Why hard shelling is a dumb idea


John ten
 

OK, Paul

before I go any further I am going to spell out the reasons why hard
shelling is dumb and my comments are only directed at the method NOT
at those who choose to use it. This is not a personal attack, please
do not take it as such. I am also not saying that you cannot get a
wing from using the process but rather that you have done far more
work than you you need to do, will most likely have have a heavier
wing and may have a less accurate product. For reasons I will expand
upon in a moment you may well also finish up with an inferior level of
finish.

Firstly lets clearly define what we are trying to achieve:

a smooth, straight, accurate, structurally efficient aerodynamically
correct airfoil with the best possible finish in the shortest possible
time.

The final shape is the outside. The outside is the resultant of (
starting at the bottom surface) paint, primer surfacer, micro/filler
,glass, glass foam interface, foam ...center line and then the same
series in reverse.

All of us only have so much sanding in us. Eventually the most
diligent and persistent of us will give up and go fly so let me submit
that the smart thing to do is to spend that resource wisely.

Finishing occurs at the point in a project when our physical,
financial, energy and enthusiasm resources are at an ebb.
Unfortunately, two factors conspire to get us. The first factor is
that the last thing we do is the first thing that everyone sees and
unfortunately the total quality is often judged by the finish. It
behooves us to get the finish to the highest possible standard (but
not at any cost or weight). What is the acceptable standard? Short
answer - luxury car paint finish is a good standard to aim for.

The second factor is that not everyone realises that the top coat is
best regarded as colour and shine on the substrate. Spraying 30
microns of paint on a cheese grater will not transform it into a
mirror. So the substrate has to be your very best work so do it once
and do it right.

Finishing is a progressive process. First flat, then increasingly
smooth. And there is a difference - a pool ball is smooth but it is
not flat, the billiard table is flat but it is not smooth. Polishing
the slate under the felt will not make the fabric finish any smoother.

All the issues that Paul as identified as being rectified could and
should have been rectified by sanding the foam. Foam is much easier
to sand than micro (we will get to glass in a moment). It is also of
uniform density so it sands evenly and quickly. You are subtracting
weight. The process is fast, easy and you are working below the final
profile.

You are neither micro cure cycle time dependent nor faced with having
to spread, smooth, cure fill, sand, fill,each time adding weight,
making dust.

Break though the shell whilst sanding and the foam is gone in a
heartbeat - more repairs needed, more weight, more wait. And what
shape do you finish the hard shell to? If you use the final finish
template (and there is is no other option) by definition when you
finish the construction process, you will be adding additional
material unevenly on top of what you have tried to make the correct
shape. Result? An inescapably incorrect shape.

But that is not all.

All that work and you have achieved a surface finish which is
inappropriate and unnecessary for that stage in the finish.

You have a surface which provides a poorer bond interface between the
glass and the foam than the chemical and mechanical bond provided
using the original approach. More resin is then required to bond the
glass to the micro surface and again it is only a mechanical bond.

The glass bundles have a rigid under surface - which means that they
do finish up lying under and over to a greater degree than the wet on
wet method combined with peel ply (which should be applied to every
square inch of the surface.) The net result is that the glass surface
is a raised mesh which is less securely bonded to the micro below and
is located above the the correct profile.

And it gets worse. Now you have to sand the glass surface to dull to
bond the micro, so off comes structural strength. The glass bundles
are not as straight as they could be and then we deliberately sand
through them...

Lets summarise then.

Hard shelling adds weight, is slower, results in the wrong profile,
degrades bond strength between glass and foam, results in a weaker
glass structure - and then you have to do it all again!! Remember the
sanding effort is a finite resource and you have spent half of it
already...

Hardshelling makes as much sense as practice bleeding..

Hope that explains the one liner a little more clearly..

John










--- In Q-LIST@..., "Paul Buckley" <paulbuckley@...> wrote:

Me too!

I actually aligned the two outer wing cores vertically on my bench,
shearweb down, between two long straight edges which matched the taper
of the wings, thus ensuring that the shearweb was flat and straight,
as were all other joined surfaces. I also pinned the joint with short
wood dowels located on the level lines, but that isn't really
necessary as you can simply lightly clamp two straight boards on each
side of the wing surfaces across the joint (as they are sitting
vertically, on the shearweb), which will ensure that the panels are
aligned accurately.
When cured both wings were then offered up to the center section,
which was firmly fastened to the wing jig.
Result:- perfectly straight and aligned wings.
Easy peasy!

As far as 'hard shelling' is concerned, I have made two sets of
wings this way, after building a set the 'wet' way.
It is much easier to make an accurate wing by 'hard shelling' with
no bumps, hollows etc, and with the glass perfectly straight, with no
micro contamination between plies, and it is much quicker to lay the
glass down on a previously prepared, smooth, surface, not to mention
being much less messy!
The only filling required on my wings were to fill the weave and the
glass spar-cap 'steps', and I would never do it any other way, now.
Hardly a 'moronic' process!

The glass bonds to the cured micro without any problems, and is just
as strong as any other bonding providing that normal 'clean' building
practices are observed. (all of the airframe is glued together)
In any case, the weakest link is in the strength of the foam,
whichever way you do it.

Paul Buckley
Cheshire, England.

Waddelow TriQ-200.....still building.



----- Original Message -----
From: Sam Hoskins
To: Q-LIST@...
Sent: Thursday, November 15, 2007 12:26 AM
Subject: Re: [Q-LIST] Re: Initial foam alignment


Re your comment: "I am inclined to "build" the exterior BL 100-51) *to
center section (BL 51-0)* on a flat surface - let the micro dry.
Then take
the two completed wings and butter up the center (at BL00) and all
the given
jigs "work" per the plans.."

I did exactly that on the last wing I built and it was sooo much
easier.

Sam Hoskins
Murphysboro, IL

On Nov 14, 2007 6:21 PM, Michael Quinn <mquinn6@...> wrote:

>
> John, Everything makes sense after you do it... I just have not
done this
> before. I wish there was someone local to Charlotte that is a
few steps
> ahead of me so I could work w/ them and learn - then mine would
be better by
> one generation of build experience! I think thru the process
many times
> before attacking it so that I can reduce the "damn I did it the
hard way..."
> I am certain w/ pracitce/experience it will become easier. I
re-re-reread
> the plans and they talk about the jig - but the female jigs only
were
> supporting one section of foam or the other (or are they
bridging it?!?! - I
> have female jigs of 3/4 plywood (scared b/c of the which hat
potential since
> they are cut square and "should" only make contact with the wing
in one
> point (lowest side of the wing). Do you micro and pin the
joints? I look at
> jigs from the picts sent to me from others and they look nothing
like the
> plans. I just am running thru the build process of the main wing
and it goes
> like - check everything for fit and alignment - recheck this at
least 100
> times. assemble the center joint less than 1/16 gap (I do not
have the plans
> in front of me - but the purpose is for complete bond and reduce
the risk of
> exothermic and melting foam and making a non bonded gap (yes?)). Ok,
> assuming gravity still is working in the downward direction -
doesn't it
> make the center section of the main wing "want" to pull apart. I
noticed the
> 5min. epoxy between the foam and female jigs - assume that give
you enough
> time to work the foam into final resting place after lathing -
then it hold
> until the micro cures. Continuing on, the external two foam wing
cores
> (already check fitted 100 times) are buttered with micro and put
onto the
> assembly that I just completed (5 min. epoxy should hold it
right?). Now -
> the female wing jig is on the center section (the plan show it
on the
> external foam cores! this would change the angles of dihedral
and make
> "curved" wings....), thus I scratch my brain (but not thru the
nose)... If
> they are on the exterior part of the wing - I am inclined to
"build" the
> exterior BL 100-51) *to center section (BL 51-0)* on a flat
surface - let
> the micro dry. Then take the two completed wings and butter up
the center
> (at BL00) and all the given jigs "work" per the plans....
Hardshelling =
> slathering and curing, sanding micro prior to starting to glass?
I have read
> several success stories about this method - my fear is the less
than optimum
> bond between the hardened micro and the glass lay-up. And weight
(which the
> argument is you will have to use that micro on the outside
otherwise). Since
> one does not peel ply the micro (since it is sanded down to
true) - the last
> sanding would be done with 60 grit to leave connection points of
pure epoxy
> prior to glass. Please be gentile I am a virgin with regards to the
> quickie.... M. *Not certain on BL measurements - just pulling
these numbers
> from what I thought I remember reading...
>
> To: Q-LIST@... <Q-LIST%40yahoogroups.comFrom>:
> johntenhave@... <johntenhave%40yahoo.comDate>: Wed, 14 Nov 2007
> 08:25:38 +0000Subject: [Q-LIST] Re: Initial foam alignment
>
> M,you are attempting to partially fix one problem whilst
ignoring therest
> of the process. The problem you are trying to fix will
beunlikely to exist
> if you follow a very well worn path.Let me add the following
suggestions
> and forgive me if some of thesethings seem so trivial as to be
too obvious
> to state.1. The final product accuracy will be dependent upon
the sum of
> theerrors in each of the steps leading to the final product. i.e.
> jig,templates, hot wiring, joining, glassing, filling.2. Get
your jig
> right, and spend as much time on it as is needed toget the
desired level of
> accuracy. Remember that a jig is a devicedesigned to permit
ordinary levels
> of skill to achieve levels ofaccuracy higher than normally
possible. 3. Get
> your hot wire templates spot on, make them as thin as
possibleand make sure
> that they permit a smooth passage of the the hot wire.errors
come from
> snagging wires, dragging drooping wires, cooling ofthe wires,
and hidden
> obstructions. Why thin? remember that you are cutting a taper
and if you use
> eachtemplate twice you will cut foam matching faces. Each face
will usethe
> same face/edge of the template. One face/edge will be adjacent
tothe foam
> but the other foam block will be spaced out by the thicknessof
the template
> and will cut oversize. To better visualise this, thinkabout
cutting a
> witches hat out of foam in two parts. Imagine a 1"thick template
halfway up
> the hat. with the hat upright, the top halfwill use the top edge
of the
> template. Cutting the bottom half willstill use the top edge of
the template
> but the taper will mean thatthe wire meets the top of the foam
on an angle
> and will cut over size. 4. Smooth passage of the wire means
smooth templates
> and smoothoperators. 5. Snagging comes from :a. the nails
holding the
> templates to the foam at an angle whichintersects the wire path
- so point
> them inwards and locate them aninch or so from the cut
surface.b. the wire
> hitting blobs of micro joining blocks prior to hot wiring- so
use very
> little, and leave the edges free of micro ~ 1/4" or so.You can
fill this
> gap later and there is no point in making thejoint any stronger
than the
> parent foam. The foam is a mold, thestructure is the glass. 6.
Drooping
> comes from wire lengthening, wire dragging and unevenheating and
poor
> technique.7. When cutting the second half of a wing block put
the core
> back intothe block from which you have just cut it.Some
suggestions : use
> 0.032" stainless steel mig welding wire whichis orders of magnitude
> stronger than lockwire, use a good power supplywhich you can
control quickly
> and easily, build a strong light hotwiresaw and heat and tighten
the wire
> till your eyes bleed.. Plucking thewire will tell you when you
have reached
> yield. Practice at different temps and speed until you get dogbone
> freeshapes. This means slow on sharp curves, faster on shallow
curves,tight
> hot wires and smooth accurate number following - at both ends.8.
> Choreograph each cut before you make it and make sure the saw
canreach the
> whole cut, the weights used to hold everything down can
becleared, and the
> saw power supply cable is long enough - remember thatif you snag
you stop,
> if you stop you burn and cut over size - sothe immediate action
if you snag
> is out at right angles to the template.9. store your cores in
the cut out
> portions.10 join the cores in the jig and run a straight edge along
> theleading edge to maximise alignment. Split differences and aim
to makeany
> error a hollow rather than a hump.11. When glued remember this -
0.020" of
> glass over corrugated ironwill not change the surface into an
ice rink so
> sand your foam with along sanding block, a long straight edge
and along the
> lines whichjoin the talking lines spanwise. Foam is much much
easier to sand
> thaneither micro or glass. and get it to within 0.030" or so.
Use lightand
> sand intelligently. One stroke of the sanding block will make
adifference.
> Do not hard shell - this is a moronic process. Lets continue the
> conversation when you get to glassing, there arelots of ways to
make that
> simpler and easier as well. Hope this helpsJohn--- In
> Q-LIST@... <Q-LIST%40yahoogroups.com>, "mtyquinn665"
> <mquinn6@> wrote:>> I am trying VERY hard not to reinvent the
wheel but I
> am attempting to > build the wing on a jig and see posting where
washout and
> wing > alignment (of the foam) caused the final product to not
be as perfect
> > as intended. (any sanding to match the other foam indicates an
inacuracy
> in following the template when hot wiring - then one sands to >
match and
> you are left with an "original" airfoil)> > My thought is to
make a slot cut
> (90 degrees perpendicular to the > surface) 1/2 inch deep at the
WL between
> the foam sections and use a > 1/16" x 1" ( x width of the wing
at that point
> minus 1 in or so) strip > of plastic as a key (this concept is
from years of
> woodworking and what > we call "biskets"). > > To test for
levelness a equal
> length wood skewer could be inserted > (using a small square to
insure
> perpendicular to skin in 2 planes) > until it makes contact w/
the plastic
> (prior to glassing)and a level > could be placed on top of the
skewers. > >
> Does this make any sense?> > M.>
>
> __________________________________________________________
> Climb to the top of the charts! Play Star Shuffle: the word scramble
> challenge with star power.
>
http://club.live.com/star_shuffle.aspx?icid=starshuffle_wlmailtextlink_oct
>
>
>
>
>
>

--
Sam Hoskins
www.MistakeProofing.Net
www.MistakeProofing.net/blog/
618-967-0016 ph.
312-212-4086 fax








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Paul Buckley
 

John

I disagree with almost everything that you have said, except maybe the dust!

It is quite obvious that you have never tried or seen this method, which is well documented.

I reiterate that my wings are as perfect as they could possibly be, without any filler, and that they only require a primer surfacer to finish.

So the substrate has to be your very best work so do it once and do it right.<<<<
Exactly!

you have done far more
work than you need to do, will most likely have a heavier
wing and may have a less accurate product <<<<<

Why more work? By all accounts, most builders spend an inordinate amount of time sanding-filling, sanding-filling, creating copious amounts of dust in the process.

Why heavier? Using the hard shell method, most of the micro is sanded away and is only there to provide a straight, hard surface on which to lay the glass.

Why less accurate? You talk about sanding the bare, foam cores. Surely, doing that destroys any accuracy that you have tried to achieve by making accurate 'thin' templates!
(and talking about your reasons for using a thin template is rather like saying that if your pitot head is on the port wing tip, turning left will give you an ASI reading that is lower than a right turn.
No doubt it will, but it is academic and unreadable.)

You talk about 'only a mechanical bond' between the glass and the hard shelled surface. Isn't virtually all of the airframe built relying on a mechanical bond? Have you ever tried to separate two mechanically bonded surfaces?
The 'mechanical' bond is every bit as strong as any other bond on the airframe, which I believe holds together pretty well, provided, like everything else, it is done using the correct techniques.
In any case, the weakest link in the 'skin to foam' bonding is the foam itself, and I have built test pieces (documented some time ago) using both methods of construction, and there was no difference
in the bonding strengths.

Break though the shell whilst sanding and the foam is gone in a
heartbeat - more repairs needed, more weight, more wait<<<<

Rubbish! Are you going to use a belt sander??
When sanding the shell, using a spline, you can clearly see when the micro is becoming thin, and that is when you stop!
And even if you do break through, it is neither catastrophic or a problem.
However, as the foam cores have been accurately cut and jigged in the first place, there will be no high spots!


And what shape do you finish the hard shell to? If you use the final finish
template (and there is is no other option) by definition when you
finish the construction process, you will be adding additional
material unevenly on top of what you have tried to make the correct
shape. Result? An inescapably incorrect shape. <<<<<

Really John? I must have missed something. In my 24 years of being on the 'Quickie' scene, I have never yet seen a 'final finish' template.
Have you? Has anyone?
The hard shell is finished to the same shape as the underlying foam cores.
Well, to 25thou. anyway! Hopefully, that is good enough!

And it gets worse. Now you have to sand the glass surface to dull to
bond the micro, so off comes structural strength. The glass bundles
are not as straight as they could be and then we deliberately sand
through them...<<<<<<<<<

Tell me John, do you not have to sand the glass surface in order to bond the micro filler when using the 'conventional' technique??
Surely you are not advocating the use of peel ply over the whole wing area? It is a well know fact that doing so is a no-no because it adds a lot of weight..........
And, using the hard shell method, it is easy to get the glass fibres dead straight......and I mean, dead straight!

There is no doubt that you are a clever and intelligent man, John, but I think that you are neither practical or experienced in the building of glass fibre aeroplanes.
You suffer from what a lot of engineers suffer from, the addiction to minutia.
You are not building a Swiss watch.........I pay avid attention to detail and am a perfectionist, but you take your arguments beyond sensible reason and practicality.

I could go on (and on and on) but I haven't the time or the patience.......if anyone would like to discuss the pros and cons I am available off list...... with lots of photos!

Paul Buckley
Cheshire
England

TriQ-200
Still building............





----- Original Message -----
From: johntenhave
To: Q-LIST@...
Sent: Thursday, November 15, 2007 8:54 AM
Subject: [Q-LIST] Why hard shelling is a dumb idea


OK, Paul

before I go any further I am going to spell out the reasons why hard
shelling is dumb and my comments are only directed at the method NOT
at those who choose to use it. This is not a personal attack, please
do not take it as such. I am also not saying that you cannot get a
wing from using the process but rather that you have done far more
work than you you need to do, will most likely have have a heavier
wing and may have a less accurate product. For reasons I will expand
upon in a moment you may well also finish up with an inferior level of
finish.

Firstly lets clearly define what we are trying to achieve:

a smooth, straight, accurate, structurally efficient aerodynamically
correct airfoil with the best possible finish in the shortest possible
time.

The final shape is the outside. The outside is the resultant of (
starting at the bottom surface) paint, primer surfacer, micro/filler
,glass, glass foam interface, foam ...center line and then the same
series in reverse.

All of us only have so much sanding in us. Eventually the most
diligent and persistent of us will give up and go fly so let me submit
that the smart thing to do is to spend that resource wisely.

Finishing occurs at the point in a project when our physical,
financial, energy and enthusiasm resources are at an ebb.
Unfortunately, two factors conspire to get us. The first factor is
that the last thing we do is the first thing that everyone sees and
unfortunately the total quality is often judged by the finish. It
behooves us to get the finish to the highest possible standard (but
not at any cost or weight). What is the acceptable standard? Short
answer - luxury car paint finish is a good standard to aim for.

The second factor is that not everyone realises that the top coat is
best regarded as colour and shine on the substrate. Spraying 30
microns of paint on a cheese grater will not transform it into a
mirror. So the substrate has to be your very best work so do it once
and do it right.

Finishing is a progressive process. First flat, then increasingly
smooth. And there is a difference - a pool ball is smooth but it is
not flat, the billiard table is flat but it is not smooth. Polishing
the slate under the felt will not make the fabric finish any smoother.

All the issues that Paul as identified as being rectified could and
should have been rectified by sanding the foam. Foam is much easier
to sand than micro (we will get to glass in a moment). It is also of
uniform density so it sands evenly and quickly. You are subtracting
weight. The process is fast, easy and you are working below the final
profile.

You are neither micro cure cycle time dependent nor faced with having
to spread, smooth, cure fill, sand, fill,each time adding weight,
making dust.

Break though the shell whilst sanding and the foam is gone in a
heartbeat - more repairs needed, more weight, more wait. And what
shape do you finish the hard shell to? If you use the final finish
template (and there is is no other option) by definition when you
finish the construction process, you will be adding additional
material unevenly on top of what you have tried to make the correct
shape. Result? An inescapably incorrect shape.

But that is not all.

All that work and you have achieved a surface finish which is
inappropriate and unnecessary for that stage in the finish.

You have a surface which provides a poorer bond interface between the
glass and the foam than the chemical and mechanical bond provided
using the original approach. More resin is then required to bond the
glass to the micro surface and again it is only a mechanical bond.

The glass bundles have a rigid under surface - which means that they
do finish up lying under and over to a greater degree than the wet on
wet method combined with peel ply (which should be applied to every
square inch of the surface.) The net result is that the glass surface
is a raised mesh which is less securely bonded to the micro below and
is located above the the correct profile.

And it gets worse. Now you have to sand the glass surface to dull to
bond the micro, so off comes structural strength. The glass bundles
are not as straight as they could be and then we deliberately sand
through them...

Lets summarise then.

Hard shelling adds weight, is slower, results in the wrong profile,
degrades bond strength between glass and foam, results in a weaker
glass structure - and then you have to do it all again!! Remember the
sanding effort is a finite resource and you have spent half of it
already...

Hardshelling makes as much sense as practice bleeding..

Hope that explains the one liner a little more clearly..

John


--- In Q-LIST@..., "Paul Buckley" <paulbuckley@...> wrote:
>
> Me too!
>
> I actually aligned the two outer wing cores vertically on my bench,
shearweb down, between two long straight edges which matched the taper
of the wings, thus ensuring that the shearweb was flat and straight,
as were all other joined surfaces. I also pinned the joint with short
wood dowels located on the level lines, but that isn't really
necessary as you can simply lightly clamp two straight boards on each
side of the wing surfaces across the joint (as they are sitting
vertically, on the shearweb), which will ensure that the panels are
aligned accurately.
> When cured both wings were then offered up to the center section,
which was firmly fastened to the wing jig.
> Result:- perfectly straight and aligned wings.
> Easy peasy!
>
> As far as 'hard shelling' is concerned, I have made two sets of
wings this way, after building a set the 'wet' way.
> It is much easier to make an accurate wing by 'hard shelling' with
no bumps, hollows etc, and with the glass perfectly straight, with no
micro contamination between plies, and it is much quicker to lay the
glass down on a previously prepared, smooth, surface, not to mention
being much less messy!
> The only filling required on my wings were to fill the weave and the
glass spar-cap 'steps', and I would never do it any other way, now.
> Hardly a 'moronic' process!
>
> The glass bonds to the cured micro without any problems, and is just
as strong as any other bonding providing that normal 'clean' building
practices are observed. (all of the airframe is glued together)
> In any case, the weakest link is in the strength of the foam,
whichever way you do it.
>
> Paul Buckley
> Cheshire, England.
>
> Waddelow TriQ-200.....still building.
>
>
>
> ----- Original Message -----
> From: Sam Hoskins
> To: Q-LIST@...
> Sent: Thursday, November 15, 2007 12:26 AM
> Subject: Re: [Q-LIST] Re: Initial foam alignment
>
>
> Re your comment: "I am inclined to "build" the exterior BL 100-51) *to
> center section (BL 51-0)* on a flat surface - let the micro dry.
Then take
> the two completed wings and butter up the center (at BL00) and all
the given
> jigs "work" per the plans.."
>
> I did exactly that on the last wing I built and it was sooo much
easier.
>
> Sam Hoskins
> Murphysboro, IL
>
> On Nov 14, 2007 6:21 PM, Michael Quinn <mquinn6@...> wrote:
>
> >
> > John, Everything makes sense after you do it... I just have not
done this
> > before. I wish there was someone local to Charlotte that is a
few steps
> > ahead of me so I could work w/ them and learn - then mine would
be better by
> > one generation of build experience! I think thru the process
many times
> > before attacking it so that I can reduce the "damn I did it the
hard way..."
> > I am certain w/ pracitce/experience it will become easier. I
re-re-reread
> > the plans and they talk about the jig - but the female jigs only
were
> > supporting one section of foam or the other (or are they
bridging it?!?! - I
> > have female jigs of 3/4 plywood (scared b/c of the which hat
potential since
> > they are cut square and "should" only make contact with the wing
in one
> > point (lowest side of the wing). Do you micro and pin the
joints? I look at
> > jigs from the picts sent to me from others and they look nothing
like the
> > plans. I just am running thru the build process of the main wing
and it goes
> > like - check everything for fit and alignment - recheck this at
least 100
> > times. assemble the center joint less than 1/16 gap (I do not
have the plans
> > in front of me - but the purpose is for complete bond and reduce
the risk of
> > exothermic and melting foam and making a non bonded gap (yes?)). Ok,
> > assuming gravity still is working in the downward direction -
doesn't it
> > make the center section of the main wing "want" to pull apart. I
noticed the
> > 5min. epoxy between the foam and female jigs - assume that give
you enough
> > time to work the foam into final resting place after lathing -
then it hold
> > until the micro cures. Continuing on, the external two foam wing
cores
> > (already check fitted 100 times) are buttered with micro and put
onto the
> > assembly that I just completed (5 min. epoxy should hold it
right?). Now -
> > the female wing jig is on the center section (the plan show it
on the
> > external foam cores! this would change the angles of dihedral
and make
> > "curved" wings....), thus I scratch my brain (but not thru the
nose)... If
> > they are on the exterior part of the wing - I am inclined to
"build" the
> > exterior BL 100-51) *to center section (BL 51-0)* on a flat
surface - let
> > the micro dry. Then take the two completed wings and butter up
the center
> > (at BL00) and all the given jigs "work" per the plans....
Hardshelling =
> > slathering and curing, sanding micro prior to starting to glass?
I have read
> > several success stories about this method - my fear is the less
than optimum
> > bond between the hardened micro and the glass lay-up. And weight
(which the
> > argument is you will have to use that micro on the outside
otherwise). Since
> > one does not peel ply the micro (since it is sanded down to
true) - the last
> > sanding would be done with 60 grit to leave connection points of
pure epoxy
> > prior to glass. Please be gentile I am a virgin with regards to the
> > quickie.... M. *Not certain on BL measurements - just pulling
these numbers
> > from what I thought I remember reading...
> >
> > To: Q-LIST@... <Q-LIST%40yahoogroups.comFrom>:
> > johntenhave@... <johntenhave%40yahoo.comDate>: Wed, 14 Nov 2007
> > 08:25:38 +0000Subject: [Q-LIST] Re: Initial foam alignment
> >
> > M,you are attempting to partially fix one problem whilst
ignoring therest
> > of the process. The problem you are trying to fix will
beunlikely to exist
> > if you follow a very well worn path.Let me add the following
suggestions
> > and forgive me if some of thesethings seem so trivial as to be
too obvious
> > to state.1. The final product accuracy will be dependent upon
the sum of
> > theerrors in each of the steps leading to the final product. i.e.
> > jig,templates, hot wiring, joining, glassing, filling.2. Get
your jig
> > right, and spend as much time on it as is needed toget the
desired level of
> > accuracy. Remember that a jig is a devicedesigned to permit
ordinary levels
> > of skill to achieve levels ofaccuracy higher than normally
possible. 3. Get
> > your hot wire templates spot on, make them as thin as
possibleand make sure
> > that they permit a smooth passage of the the hot wire.errors
come from
> > snagging wires, dragging drooping wires, cooling ofthe wires,
and hidden
> > obstructions. Why thin? remember that you are cutting a taper
and if you use
> > eachtemplate twice you will cut foam matching faces. Each face
will usethe
> > same face/edge of the template. One face/edge will be adjacent
tothe foam
> > but the other foam block will be spaced out by the thicknessof
the template
> > and will cut oversize. To better visualise this, thinkabout
cutting a
> > witches hat out of foam in two parts. Imagine a 1"thick template
halfway up
> > the hat. with the hat upright, the top halfwill use the top edge
of the
> > template. Cutting the bottom half willstill use the top edge of
the template
> > but the taper will mean thatthe wire meets the top of the foam
on an angle
> > and will cut over size. 4. Smooth passage of the wire means
smooth templates
> > and smoothoperators. 5. Snagging comes from :a. the nails
holding the
> > templates to the foam at an angle whichintersects the wire path
- so point
> > them inwards and locate them aninch or so from the cut
surface.b. the wire
> > hitting blobs of micro joining blocks prior to hot wiring- so
use very
> > little, and leave the edges free of micro ~ 1/4" or so.You can
fill this
> > gap later and there is no point in making thejoint any stronger
than the
> > parent foam. The foam is a mold, thestructure is the glass. 6.
Drooping
> > comes from wire lengthening, wire dragging and unevenheating and
poor
> > technique.7. When cutting the second half of a wing block put
the core
> > back intothe block from which you have just cut it.Some
suggestions : use
> > 0.032" stainless steel mig welding wire whichis orders of magnitude
> > stronger than lockwire, use a good power supplywhich you can
control quickly
> > and easily, build a strong light hotwiresaw and heat and tighten
the wire
> > till your eyes bleed.. Plucking thewire will tell you when you
have reached
> > yield. Practice at different temps and speed until you get dogbone
> > freeshapes. This means slow on sharp curves, faster on shallow
curves,tight
> > hot wires and smooth accurate number following - at both ends.8.
> > Choreograph each cut before you make it and make sure the saw
canreach the
> > whole cut, the weights used to hold everything down can
becleared, and the
> > saw power supply cable is long enough - remember thatif you snag
you stop,
> > if you stop you burn and cut over size - sothe immediate action
if you snag
> > is out at right angles to the template.9. store your cores in
the cut out
> > portions.10 join the cores in the jig and run a straight edge along
> > theleading edge to maximise alignment. Split differences and aim
to makeany
> > error a hollow rather than a hump.11. When glued remember this -
0.020" of
> > glass over corrugated ironwill not change the surface into an
ice rink so
> > sand your foam with along sanding block, a long straight edge
and along the
> > lines whichjoin the talking lines spanwise. Foam is much much
easier to sand
> > thaneither micro or glass. and get it to within 0.030" or so.
Use lightand
> > sand intelligently. One stroke of the sanding block will make
adifference.
> > Do not hard shell - this is a moronic process. Lets continue the
> > conversation when you get to glassing, there arelots of ways to
make that
> > simpler and easier as well. Hope this helpsJohn--- In
> > Q-LIST@... <Q-LIST%40yahoogroups.com>, "mtyquinn665"
> > <mquinn6@> wrote:>> I am trying VERY hard not to reinvent the
wheel but I
> > am attempting to > build the wing on a jig and see posting where
washout and
> > wing > alignment (of the foam) caused the final product to not
be as perfect
> > > as intended. (any sanding to match the other foam indicates an
> inacuracy
> > in following the template when hot wiring - then one sands to >
match and
> > you are left with an "original" airfoil)> > My thought is to
make a slot cut
> > (90 degrees perpendicular to the > surface) 1/2 inch deep at the
WL between
> > the foam sections and use a > 1/16" x 1" ( x width of the wing
at that point
> > minus 1 in or so) strip > of plastic as a key (this concept is
from years of
> > woodworking and what > we call "biskets"). > > To test for
levelness a equal
> > length wood skewer could be inserted > (using a small square to
insure
> > perpendicular to skin in 2 planes) > until it makes contact w/
the plastic
> > (prior to glassing)and a level > could be placed on top of the
skewers. > >
> > Does this make any sense?> > M.>
> >
> > __________________________________________________________
> > Climb to the top of the charts! Play Star Shuffle: the word scramble
> > challenge with star power.
> >
http://club.live.com/star_shuffle.aspx?icid=starshuffle_wlmailtextlink_oct
> >
> >
> >
> >
> >
> >
>
> --
> Sam Hoskins
> www.MistakeProofing.Net
> www.MistakeProofing.net/blog/
> 618-967-0016 ph.
> 312-212-4086 fax
>
>
>
>
>
>
>
>
>
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>
>
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.503 / Virus Database: 269.15.31/1129 - Release Date:
13/11/2007 21:22
>
>
>
>






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Checked by AVG Free Edition.
Version: 7.5.503 / Virus Database: 269.15.32/1131 - Release Date: 14/11/2007 16:54


Paul Buckley
 

John

Without malice, I disagree with almost everything that you have said, except maybe the dust!

It is quite obvious that you have never tried or seen this method, which is well documented.

I reiterate that my wings are as perfect as they could possibly be, with virtually no micro filler, and that they only require a primer surfacer to finish.

So the substrate has to be your very best work so do it once and do it right.<<<<
Exactly!

you have done far more
work than you need to do, will most likely have a heavier
wing and may have a less accurate product <<<<<

Why more work? By all accounts, most builders spend an inordinate amount of time sanding-filling, sanding-filling, creating copious amounts of dust in the process.

Why heavier? Using the hard shell method, most of the micro is sanded away and is only there to provide a straight, hard surface on which to lay the glass, the resultant cured surface of which is nigh on perfect.

Why less accurate? You talk about sanding the bare, foam cores. Surely, doing that destroys any accuracy that you have tried to achieve by making accurate 'thin' templates!
(and talking about your reasons for using a thin template is rather like saying that if your pitot head is on the port wing tip, turning left will give you an ASI reading that is lower than a right turn.
No doubt it will, but it is both academic and unreadable)

You talk about 'only a mechanical bond' between the glass and the hard shelled surface. Isn't virtually all of the airframe built relying on mechanical bonds? Have you ever tried to separate two mechanically bonded surfaces?
The 'mechanical' bond is every bit as strong as any other bond on the airframe, which I believe holds together pretty well, provided, like everything else, it is done using the correct techniques.
In any case, the weakest link in the 'skin to foam' bonding is the foam itself, and I have built test pieces (documented some time ago) using both methods of construction, and there was no discernable difference
in the bonding strengths.

Break though the shell whilst sanding and the foam is gone in a
heartbeat - more repairs needed, more weight, more wait<<<<

Rubbish! Are you going to use a belt sander??
When sanding the shell, using a spline, you can clearly see when the micro is becoming thin, and that is when you stop.
And as the foam cores have been accurately cut and jigged in the first place, there will be no high spots to break through!
But even if you do break through, it is neither catastrophic or a problem.

And what shape do you finish the hard shell to? If you use the final finish
template (and there is is no other option) by definition when you
finish the construction process, you will be adding additional
material unevenly on top of what you have tried to make the correct
shape. Result? An inescapably incorrect shape. <<<<<<<

Really John? I must have missed something. In my 24 years of being on the 'Quickie' scene, I have never yet seen a 'final finish' template.
Have you? Has anyone?
The hard shell is finished to the same shape as the underlying foam cores.
Well, to 25thou. anyway! Hopefully, that is good enough!

And it gets worse. Now you have to sand the glass surface to dull to
bond the micro, so off comes structural strength. The glass bundles
are not as straight as they could be and then we deliberately sand
through them...<<<<<<<<<<

Tell me John, do you not have to sand the glass wing surface in order to bond the micro filler when using the 'conventional' technique??
Surely you are not advocating the use of peel ply over the whole wing area? It is a well know fact that doing so is a no-no because it adds a lot of weight..........
And, using the hard shell method, it is easy to get the glass fibres dead straight......and I mean, dead straight!

There is no doubt that you are a clever and intelligent man, John, but I think that you are neither practical or experienced in the building of glass fibre aeroplanes.
You suffer from what a lot of engineers suffer from, the addiction to minutia.
You are not building a Swiss watch.........I pay avid attention to detail and am a perfectionist, but you take your arguments beyond sensible reason and practicality.

I could go on (and on and on) but I haven't the time or the patience.......if anyone would like to discuss the pros and cons I am available off list...... with lots of photos!

Paul Buckley
Cheshire
England

TriQ-200
Still building............





----- Original Message -----
From: johntenhave
To: Q-LIST@...
Sent: Thursday, November 15, 2007 8:54 AM
Subject: [Q-LIST] Why hard shelling is a dumb idea


OK, Paul

before I go any further I am going to spell out the reasons why hard
shelling is dumb and my comments are only directed at the method NOT
at those who choose to use it. This is not a personal attack, please
do not take it as such. I am also not saying that you cannot get a
wing from using the process but rather that you have done far more
work than you you need to do, will most likely have have a heavier
wing and may have a less accurate product. For reasons I will expand
upon in a moment you may well also finish up with an inferior level of
finish.

Firstly lets clearly define what we are trying to achieve:

a smooth, straight, accurate, structurally efficient aerodynamically
correct airfoil with the best possible finish in the shortest possible
time.

The final shape is the outside. The outside is the resultant of (
starting at the bottom surface) paint, primer surfacer, micro/filler
,glass, glass foam interface, foam ...center line and then the same
series in reverse.

All of us only have so much sanding in us. Eventually the most
diligent and persistent of us will give up and go fly so let me submit
that the smart thing to do is to spend that resource wisely.

Finishing occurs at the point in a project when our physical,
financial, energy and enthusiasm resources are at an ebb.
Unfortunately, two factors conspire to get us. The first factor is
that the last thing we do is the first thing that everyone sees and
unfortunately the total quality is often judged by the finish. It
behooves us to get the finish to the highest possible standard (but
not at any cost or weight). What is the acceptable standard? Short
answer - luxury car paint finish is a good standard to aim for.

The second factor is that not everyone realises that the top coat is
best regarded as colour and shine on the substrate. Spraying 30
microns of paint on a cheese grater will not transform it into a
mirror. So the substrate has to be your very best work so do it once
and do it right.

Finishing is a progressive process. First flat, then increasingly
smooth. And there is a difference - a pool ball is smooth but it is
not flat, the billiard table is flat but it is not smooth. Polishing
the slate under the felt will not make the fabric finish any smoother.

All the issues that Paul as identified as being rectified could and
should have been rectified by sanding the foam. Foam is much easier
to sand than micro (we will get to glass in a moment). It is also of
uniform density so it sands evenly and quickly. You are subtracting
weight. The process is fast, easy and you are working below the final
profile.

You are neither micro cure cycle time dependent nor faced with having
to spread, smooth, cure fill, sand, fill,each time adding weight,
making dust.

Break though the shell whilst sanding and the foam is gone in a
heartbeat - more repairs needed, more weight, more wait. And what
shape do you finish the hard shell to? If you use the final finish
template (and there is is no other option) by definition when you
finish the construction process, you will be adding additional
material unevenly on top of what you have tried to make the correct
shape. Result? An inescapably incorrect shape.

But that is not all.

All that work and you have achieved a surface finish which is
inappropriate and unnecessary for that stage in the finish.

You have a surface which provides a poorer bond interface between the
glass and the foam than the chemical and mechanical bond provided
using the original approach. More resin is then required to bond the
glass to the micro surface and again it is only a mechanical bond.

The glass bundles have a rigid under surface - which means that they
do finish up lying under and over to a greater degree than the wet on
wet method combined with peel ply (which should be applied to every
square inch of the surface.) The net result is that the glass surface
is a raised mesh which is less securely bonded to the micro below and
is located above the the correct profile.

And it gets worse. Now you have to sand the glass surface to dull to
bond the micro, so off comes structural strength. The glass bundles
are not as straight as they could be and then we deliberately sand
through them...

Lets summarise then.

Hard shelling adds weight, is slower, results in the wrong profile,
degrades bond strength between glass and foam, results in a weaker
glass structure - and then you have to do it all again!! Remember the
sanding effort is a finite resource and you have spent half of it
already...

Hardshelling makes as much sense as practice bleeding..

Hope that explains the one liner a little more clearly..

John


--- In Q-LIST@..., "Paul Buckley" <paulbuckley@...> wrote:
>
> Me too!
>
> I actually aligned the two outer wing cores vertically on my bench,
shearweb down, between two long straight edges which matched the taper
of the wings, thus ensuring that the shearweb was flat and straight,
as were all other joined surfaces. I also pinned the joint with short
wood dowels located on the level lines, but that isn't really
necessary as you can simply lightly clamp two straight boards on each
side of the wing surfaces across the joint (as they are sitting
vertically, on the shearweb), which will ensure that the panels are
aligned accurately.
> When cured both wings were then offered up to the center section,
which was firmly fastened to the wing jig.
> Result:- perfectly straight and aligned wings.
> Easy peasy!
>
> As far as 'hard shelling' is concerned, I have made two sets of
wings this way, after building a set the 'wet' way.
> It is much easier to make an accurate wing by 'hard shelling' with
no bumps, hollows etc, and with the glass perfectly straight, with no
micro contamination between plies, and it is much quicker to lay the
glass down on a previously prepared, smooth, surface, not to mention
being much less messy!
> The only filling required on my wings were to fill the weave and the
glass spar-cap 'steps', and I would never do it any other way, now.
> Hardly a 'moronic' process!
>
> The glass bonds to the cured micro without any problems, and is just
as strong as any other bonding providing that normal 'clean' building
practices are observed. (all of the airframe is glued together)
> In any case, the weakest link is in the strength of the foam,
whichever way you do it.
>
> Paul Buckley
> Cheshire, England.
>
> Waddelow TriQ-200.....still building.
>
>
>
> ----- Original Message -----
> From: Sam Hoskins
> To: Q-LIST@...
> Sent: Thursday, November 15, 2007 12:26 AM
> Subject: Re: [Q-LIST] Re: Initial foam alignment
>
>
> Re your comment: "I am inclined to "build" the exterior BL 100-51) *to
> center section (BL 51-0)* on a flat surface - let the micro dry.
Then take
> the two completed wings and butter up the center (at BL00) and all
the given
> jigs "work" per the plans.."
>
> I did exactly that on the last wing I built and it was sooo much
easier.
>
> Sam Hoskins
> Murphysboro, IL
>
> On Nov 14, 2007 6:21 PM, Michael Quinn <mquinn6@...> wrote:
>
> >
> > John, Everything makes sense after you do it... I just have not
done this
> > before. I wish there was someone local to Charlotte that is a
few steps
> > ahead of me so I could work w/ them and learn - then mine would
be better by
> > one generation of build experience! I think thru the process
many times
> > before attacking it so that I can reduce the "damn I did it the
hard way..."
> > I am certain w/ pracitce/experience it will become easier. I
re-re-reread
> > the plans and they talk about the jig - but the female jigs only
were
> > supporting one section of foam or the other (or are they
bridging it?!?! - I
> > have female jigs of 3/4 plywood (scared b/c of the which hat
potential since
> > they are cut square and "should" only make contact with the wing
in one
> > point (lowest side of the wing). Do you micro and pin the
joints? I look at
> > jigs from the picts sent to me from others and they look nothing
like the
> > plans. I just am running thru the build process of the main wing
and it goes
> > like - check everything for fit and alignment - recheck this at
least 100
> > times. assemble the center joint less than 1/16 gap (I do not
have the plans
> > in front of me - but the purpose is for complete bond and reduce
the risk of
> > exothermic and melting foam and making a non bonded gap (yes?)). Ok,
> > assuming gravity still is working in the downward direction -
doesn't it
> > make the center section of the main wing "want" to pull apart. I
noticed the
> > 5min. epoxy between the foam and female jigs - assume that give
you enough
> > time to work the foam into final resting place after lathing -
then it hold
> > until the micro cures. Continuing on, the external two foam wing
cores
> > (already check fitted 100 times) are buttered with micro and put
onto the
> > assembly that I just completed (5 min. epoxy should hold it
right?). Now -
> > the female wing jig is on the center section (the plan show it
on the
> > external foam cores! this would change the angles of dihedral
and make
> > "curved" wings....), thus I scratch my brain (but not thru the
nose)... If
> > they are on the exterior part of the wing - I am inclined to
"build" the
> > exterior BL 100-51) *to center section (BL 51-0)* on a flat
surface - let
> > the micro dry. Then take the two completed wings and butter up
the center
> > (at BL00) and all the given jigs "work" per the plans....
Hardshelling =
> > slathering and curing, sanding micro prior to starting to glass?
I have read
> > several success stories about this method - my fear is the less
than optimum
> > bond between the hardened micro and the glass lay-up. And weight
(which the
> > argument is you will have to use that micro on the outside
otherwise). Since
> > one does not peel ply the micro (since it is sanded down to
true) - the last
> > sanding would be done with 60 grit to leave connection points of
pure epoxy
> > prior to glass. Please be gentile I am a virgin with regards to the
> > quickie.... M. *Not certain on BL measurements - just pulling
these numbers
> > from what I thought I remember reading...
> >
> > To: Q-LIST@... <Q-LIST%40yahoogroups.comFrom>:
> > johntenhave@... <johntenhave%40yahoo.comDate>: Wed, 14 Nov 2007
> > 08:25:38 +0000Subject: [Q-LIST] Re: Initial foam alignment
> >
> > M,you are attempting to partially fix one problem whilst
ignoring therest
> > of the process. The problem you are trying to fix will
beunlikely to exist
> > if you follow a very well worn path.Let me add the following
suggestions
> > and forgive me if some of thesethings seem so trivial as to be
too obvious
> > to state.1. The final product accuracy will be dependent upon
the sum of
> > theerrors in each of the steps leading to the final product. i.e.
> > jig,templates, hot wiring, joining, glassing, filling.2. Get
your jig
> > right, and spend as much time on it as is needed toget the
desired level of
> > accuracy. Remember that a jig is a devicedesigned to permit
ordinary levels
> > of skill to achieve levels ofaccuracy higher than normally
possible. 3. Get
> > your hot wire templates spot on, make them as thin as
possibleand make sure
> > that they permit a smooth passage of the the hot wire.errors
come from
> > snagging wires, dragging drooping wires, cooling ofthe wires,
and hidden
> > obstructions. Why thin? remember that you are cutting a taper
and if you use
> > eachtemplate twice you will cut foam matching faces. Each face
will usethe
> > same face/edge of the template. One face/edge will be adjacent
tothe foam
> > but the other foam block will be spaced out by the thicknessof
the template
> > and will cut oversize. To better visualise this, thinkabout
cutting a
> > witches hat out of foam in two parts. Imagine a 1"thick template
halfway up
> > the hat. with the hat upright, the top halfwill use the top edge
of the
> > template. Cutting the bottom half willstill use the top edge of
the template
> > but the taper will mean thatthe wire meets the top of the foam
on an angle
> > and will cut over size. 4. Smooth passage of the wire means
smooth templates
> > and smoothoperators. 5. Snagging comes from :a. the nails
holding the
> > templates to the foam at an angle whichintersects the wire path
- so point
> > them inwards and locate them aninch or so from the cut
surface.b. the wire
> > hitting blobs of micro joining blocks prior to hot wiring- so
use very
> > little, and leave the edges free of micro ~ 1/4" or so.You can
fill this
> > gap later and there is no point in making thejoint any stronger
than the
> > parent foam. The foam is a mold, thestructure is the glass. 6.
Drooping
> > comes from wire lengthening, wire dragging and unevenheating and
poor
> > technique.7. When cutting the second half of a wing block put
the core
> > back intothe block from which you have just cut it.Some
suggestions : use
> > 0.032" stainless steel mig welding wire whichis orders of magnitude
> > stronger than lockwire, use a good power supplywhich you can
control quickly
> > and easily, build a strong light hotwiresaw and heat and tighten
the wire
> > till your eyes bleed.. Plucking thewire will tell you when you
have reached
> > yield. Practice at different temps and speed until you get dogbone
> > freeshapes. This means slow on sharp curves, faster on shallow
curves,tight
> > hot wires and smooth accurate number following - at both ends.8.
> > Choreograph each cut before you make it and make sure the saw
canreach the
> > whole cut, the weights used to hold everything down can
becleared, and the
> > saw power supply cable is long enough - remember thatif you snag
you stop,
> > if you stop you burn and cut over size - sothe immediate action
if you snag
> > is out at right angles to the template.9. store your cores in
the cut out
> > portions.10 join the cores in the jig and run a straight edge along
> > theleading edge to maximise alignment. Split differences and aim
to makeany
> > error a hollow rather than a hump.11. When glued remember this -
0.020" of
> > glass over corrugated ironwill not change the surface into an
ice rink so
> > sand your foam with along sanding block, a long straight edge
and along the
> > lines whichjoin the talking lines spanwise. Foam is much much
easier to sand
> > thaneither micro or glass. and get it to within 0.030" or so.
Use lightand
> > sand intelligently. One stroke of the sanding block will make
adifference.
> > Do not hard shell - this is a moronic process. Lets continue the
> > conversation when you get to glassing, there arelots of ways to
make that
> > simpler and easier as well. Hope this helpsJohn--- In
> > Q-LIST@... <Q-LIST%40yahoogroups.com>, "mtyquinn665"
> > <mquinn6@> wrote:>> I am trying VERY hard not to reinvent the
wheel but I
> > am attempting to > build the wing on a jig and see posting where
washout and
> > wing > alignment (of the foam) caused the final product to not
be as perfect
> > > as intended. (any sanding to match the other foam indicates an
> inacuracy
> > in following the template when hot wiring - then one sands to >
match and
> > you are left with an "original" airfoil)> > My thought is to
make a slot cut
> > (90 degrees perpendicular to the > surface) 1/2 inch deep at the
WL between
> > the foam sections and use a > 1/16" x 1" ( x width of the wing
at that point
> > minus 1 in or so) strip > of plastic as a key (this concept is
from years of
> > woodworking and what > we call "biskets"). > > To test for
levelness a equal
> > length wood skewer could be inserted > (using a small square to
insure
> > perpendicular to skin in 2 planes) > until it makes contact w/
the plastic
> > (prior to glassing)and a level > could be placed on top of the
skewers. > >
> > Does this make any sense?> > M.>
> >
> > __________________________________________________________
> > Climb to the top of the charts! Play Star Shuffle: the word scramble
> > challenge with star power.
> >
http://club.live.com/star_shuffle.aspx?icid=starshuffle_wlmailtextlink_oct
> >
> >
> >
> >
> >
> >
>
> --
> Sam Hoskins
> www.MistakeProofing.Net
> www.MistakeProofing.net/blog/
> 618-967-0016 ph.
> 312-212-4086 fax
>
>
>
>
>
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John ten
 

Paul,

no offence taken, and there is nothing like a healthy, reasoned debate.

Rather than clutter the bandwidth, let your comments stand. Let me
comment briefly on incorrect assumptions and may I direct you and
anyone else how is interested to the composite finishing presentation
I have posted. I was asked to explain to the SAAA how the finish on VH
XMX was achieved, so I did.

A Long Ez has 195 sq ft of wetted area. All of it has to be finished
from foam to paint. A Q2XX is a much smaller, simpler area subset.

I have seen the hardshelling method and you are right - I have not
tried it. Its shortcomings were apparent by inspection, my teachers
(mentioned in the presentation) were masters of the faster method and
that is how I decided which was best.

Yes I am advocating peel plying every square inch of the external and
internal glass work. I will explain my reasoning why in another
posting- if it is not apparent from the presentation.

Regards

John

P.S. Re practical experience? I built and surface finished the Long
Ez used as the example in the presentation - single handed.

As one wry Vari Eze builder once noted : "more like moderately
f**king difficult!"



--- In Q-LIST@..., "Paul Buckley" <paulbuckley@...> wrote:

John

Without malice, I disagree with almost everything that you have
said, except maybe the dust!

It is quite obvious that you have never tried or seen this method,
which is well documented.

I reiterate that my wings are as perfect as they could possibly be,
with virtually no micro filler, and that they only require a primer
surfacer to finish.

So the substrate has to be your very best work so do it once
and do it right.<<<<

Exactly!

you have done far more
work than you need to do, will most likely have a heavier
wing and may have a less accurate product <<<<<

Why more work? By all accounts, most builders spend an inordinate
amount of time sanding-filling, sanding-filling, creating copious
amounts of dust in the process.

Why heavier? Using the hard shell method, most of the micro is
sanded away and is only there to provide a straight, hard surface on
which to lay the glass, the resultant cured surface of which is nigh
on perfect.

Why less accurate? You talk about sanding the bare, foam cores.
Surely, doing that destroys any accuracy that you have tried to
achieve by making accurate 'thin' templates!
(and talking about your reasons for using a thin template is rather
like saying that if your pitot head is on the port wing tip, turning
left will give you an ASI reading that is lower than a right turn.
No doubt it will, but it is both academic and unreadable)

You talk about 'only a mechanical bond' between the glass and the
hard shelled surface. Isn't virtually all of the airframe built
relying on mechanical bonds? Have you ever tried to separate two
mechanically bonded surfaces?
The 'mechanical' bond is every bit as strong as any other bond on
the airframe, which I believe holds together pretty well, provided,
like everything else, it is done using the correct techniques.
In any case, the weakest link in the 'skin to foam' bonding is the
foam itself, and I have built test pieces (documented some time ago)
using both methods of construction, and there was no discernable
difference
in the bonding strengths.

Break though the shell whilst sanding and the foam is gone in a
heartbeat - more repairs needed, more weight, more wait<<<<

Rubbish! Are you going to use a belt sander??
When sanding the shell, using a spline, you can clearly see when the
micro is becoming thin, and that is when you stop.
And as the foam cores have been accurately cut and jigged in the
first place, there will be no high spots to break through!
But even if you do break through, it is neither catastrophic or a
problem.

And what shape do you finish the hard shell to? If you use the
final finish
template (and there is is no other option) by definition when you
finish the construction process, you will be adding additional
material unevenly on top of what you have tried to make the correct
shape. Result? An inescapably incorrect shape. <<<<<<<

Really John? I must have missed something. In my 24 years of being
on the 'Quickie' scene, I have never yet seen a 'final finish' template.
Have you? Has anyone?
The hard shell is finished to the same shape as the underlying foam
cores.
Well, to 25thou. anyway! Hopefully, that is good enough!

And it gets worse. Now you have to sand the glass surface
to dull to
bond the micro, so off comes structural strength. The glass bundles
are not as straight as they could be and then we deliberately sand
through them...<<<<<<<<<<

Tell me John, do you not have to sand the glass wing surface in
order to bond the micro filler when using the 'conventional' technique??
Surely you are not advocating the use of peel ply over the whole
wing area? It is a well know fact that doing so is a no-no because it
adds a lot of weight..........
And, using the hard shell method, it is easy to get the glass fibres
dead straight......and I mean, dead straight!

There is no doubt that you are a clever and intelligent man, John,
but I think that you are neither practical or experienced in the
building of glass fibre aeroplanes.
You suffer from what a lot of engineers suffer from, the addiction
to minutia.
You are not building a Swiss watch.........I pay avid attention to
detail and am a perfectionist, but you take your arguments beyond
sensible reason and practicality.

I could go on (and on and on) but I haven't the time or the
patience.......if anyone would like to discuss the pros and cons I am
available off list...... with lots of photos!

Paul Buckley
Cheshire
England

TriQ-200
Still building............





----- Original Message -----
From: johntenhave
To: Q-LIST@...
Sent: Thursday, November 15, 2007 8:54 AM
Subject: [Q-LIST] Why hard shelling is a dumb idea


OK, Paul

before I go any further I am going to spell out the reasons why hard
shelling is dumb and my comments are only directed at the method NOT
at those who choose to use it. This is not a personal attack, please
do not take it as such. I am also not saying that you cannot get a
wing from using the process but rather that you have done far more
work than you you need to do, will most likely have have a heavier
wing and may have a less accurate product. For reasons I will expand
upon in a moment you may well also finish up with an inferior level of
finish.

Firstly lets clearly define what we are trying to achieve:

a smooth, straight, accurate, structurally efficient aerodynamically
correct airfoil with the best possible finish in the shortest possible
time.

The final shape is the outside. The outside is the resultant of (
starting at the bottom surface) paint, primer surfacer, micro/filler
,glass, glass foam interface, foam ...center line and then the same
series in reverse.

All of us only have so much sanding in us. Eventually the most
diligent and persistent of us will give up and go fly so let me submit
that the smart thing to do is to spend that resource wisely.

Finishing occurs at the point in a project when our physical,
financial, energy and enthusiasm resources are at an ebb.
Unfortunately, two factors conspire to get us. The first factor is
that the last thing we do is the first thing that everyone sees and
unfortunately the total quality is often judged by the finish. It
behooves us to get the finish to the highest possible standard (but
not at any cost or weight). What is the acceptable standard? Short
answer - luxury car paint finish is a good standard to aim for.

The second factor is that not everyone realises that the top coat is
best regarded as colour and shine on the substrate. Spraying 30
microns of paint on a cheese grater will not transform it into a
mirror. So the substrate has to be your very best work so do it once
and do it right.

Finishing is a progressive process. First flat, then increasingly
smooth. And there is a difference - a pool ball is smooth but it is
not flat, the billiard table is flat but it is not smooth. Polishing
the slate under the felt will not make the fabric finish any smoother.

All the issues that Paul as identified as being rectified could and
should have been rectified by sanding the foam. Foam is much easier
to sand than micro (we will get to glass in a moment). It is also of
uniform density so it sands evenly and quickly. You are subtracting
weight. The process is fast, easy and you are working below the final
profile.

You are neither micro cure cycle time dependent nor faced with having
to spread, smooth, cure fill, sand, fill,each time adding weight,
making dust.

Break though the shell whilst sanding and the foam is gone in a
heartbeat - more repairs needed, more weight, more wait. And what
shape do you finish the hard shell to? If you use the final finish
template (and there is is no other option) by definition when you
finish the construction process, you will be adding additional
material unevenly on top of what you have tried to make the correct
shape. Result? An inescapably incorrect shape.

But that is not all.

All that work and you have achieved a surface finish which is
inappropriate and unnecessary for that stage in the finish.

You have a surface which provides a poorer bond interface between the
glass and the foam than the chemical and mechanical bond provided
using the original approach. More resin is then required to bond the
glass to the micro surface and again it is only a mechanical bond.

The glass bundles have a rigid under surface - which means that they
do finish up lying under and over to a greater degree than the wet on
wet method combined with peel ply (which should be applied to every
square inch of the surface.) The net result is that the glass surface
is a raised mesh which is less securely bonded to the micro below and
is located above the the correct profile.

And it gets worse. Now you have to sand the glass surface to dull to
bond the micro, so off comes structural strength. The glass bundles
are not as straight as they could be and then we deliberately sand
through them...

Lets summarise then.

Hard shelling adds weight, is slower, results in the wrong profile,
degrades bond strength between glass and foam, results in a weaker
glass structure - and then you have to do it all again!! Remember the
sanding effort is a finite resource and you have spent half of it
already...

Hardshelling makes as much sense as practice bleeding..

Hope that explains the one liner a little more clearly..

John


--- In Q-LIST@..., "Paul Buckley" <paulbuckley@> wrote:
>
> Me too!
>
> I actually aligned the two outer wing cores vertically on my bench,
shearweb down, between two long straight edges which matched the taper
of the wings, thus ensuring that the shearweb was flat and straight,
as were all other joined surfaces. I also pinned the joint with short
wood dowels located on the level lines, but that isn't really
necessary as you can simply lightly clamp two straight boards on each
side of the wing surfaces across the joint (as they are sitting
vertically, on the shearweb), which will ensure that the panels are
aligned accurately.
> When cured both wings were then offered up to the center section,
which was firmly fastened to the wing jig.
> Result:- perfectly straight and aligned wings.
> Easy peasy!
>
> As far as 'hard shelling' is concerned, I have made two sets of
wings this way, after building a set the 'wet' way.
> It is much easier to make an accurate wing by 'hard shelling' with
no bumps, hollows etc, and with the glass perfectly straight, with no
micro contamination between plies, and it is much quicker to lay the
glass down on a previously prepared, smooth, surface, not to mention
being much less messy!
> The only filling required on my wings were to fill the weave and the
glass spar-cap 'steps', and I would never do it any other way, now.
> Hardly a 'moronic' process!
>
> The glass bonds to the cured micro without any problems, and is just
as strong as any other bonding providing that normal 'clean' building
practices are observed. (all of the airframe is glued together)
> In any case, the weakest link is in the strength of the foam,
whichever way you do it.
>
> Paul Buckley
> Cheshire, England.
>
> Waddelow TriQ-200.....still building.
>
>
>
> ----- Original Message -----
> From: Sam Hoskins
> To: Q-LIST@...
> Sent: Thursday, November 15, 2007 12:26 AM
> Subject: Re: [Q-LIST] Re: Initial foam alignment
>
>
> Re your comment: "I am inclined to "build" the exterior BL
100-51) *to
> center section (BL 51-0)* on a flat surface - let the micro dry.
Then take
> the two completed wings and butter up the center (at BL00) and all
the given
> jigs "work" per the plans.."
>
> I did exactly that on the last wing I built and it was sooo much
easier.
>
> Sam Hoskins
> Murphysboro, IL
>
> On Nov 14, 2007 6:21 PM, Michael Quinn <mquinn6@> wrote:
>
> >
> > John, Everything makes sense after you do it... I just have not
done this
> > before. I wish there was someone local to Charlotte that is a
few steps
> > ahead of me so I could work w/ them and learn - then mine would
be better by
> > one generation of build experience! I think thru the process
many times
> > before attacking it so that I can reduce the "damn I did it the
hard way..."
> > I am certain w/ pracitce/experience it will become easier. I
re-re-reread
> > the plans and they talk about the jig - but the female jigs only
were
> > supporting one section of foam or the other (or are they
bridging it?!?! - I
> > have female jigs of 3/4 plywood (scared b/c of the which hat
potential since
> > they are cut square and "should" only make contact with the wing
in one
> > point (lowest side of the wing). Do you micro and pin the
joints? I look at
> > jigs from the picts sent to me from others and they look nothing
like the
> > plans. I just am running thru the build process of the main wing
and it goes
> > like - check everything for fit and alignment - recheck this at
least 100
> > times. assemble the center joint less than 1/16 gap (I do not
have the plans
> > in front of me - but the purpose is for complete bond and reduce
the risk of
> > exothermic and melting foam and making a non bonded gap
(yes?)). Ok,
> > assuming gravity still is working in the downward direction -
doesn't it
> > make the center section of the main wing "want" to pull apart. I
noticed the
> > 5min. epoxy between the foam and female jigs - assume that give
you enough
> > time to work the foam into final resting place after lathing -
then it hold
> > until the micro cures. Continuing on, the external two foam wing
cores
> > (already check fitted 100 times) are buttered with micro and put
onto the
> > assembly that I just completed (5 min. epoxy should hold it
right?). Now -
> > the female wing jig is on the center section (the plan show it
on the
> > external foam cores! this would change the angles of dihedral
and make
> > "curved" wings....), thus I scratch my brain (but not thru the
nose)... If
> > they are on the exterior part of the wing - I am inclined to
"build" the
> > exterior BL 100-51) *to center section (BL 51-0)* on a flat
surface - let
> > the micro dry. Then take the two completed wings and butter up
the center
> > (at BL00) and all the given jigs "work" per the plans....
Hardshelling =
> > slathering and curing, sanding micro prior to starting to glass?
I have read
> > several success stories about this method - my fear is the less
than optimum
> > bond between the hardened micro and the glass lay-up. And weight
(which the
> > argument is you will have to use that micro on the outside
otherwise). Since
> > one does not peel ply the micro (since it is sanded down to
true) - the last
> > sanding would be done with 60 grit to leave connection points of
pure epoxy
> > prior to glass. Please be gentile I am a virgin with regards
to the
> > quickie.... M. *Not certain on BL measurements - just pulling
these numbers
> > from what I thought I remember reading...
> >
> > To: Q-LIST@ <Q-LIST%40yahoogroups.comFrom>:
> > johntenhave@ <johntenhave%40yahoo.comDate>: Wed, 14 Nov 2007
> > 08:25:38 +0000Subject: [Q-LIST] Re: Initial foam alignment
> >
> > M,you are attempting to partially fix one problem whilst
ignoring therest
> > of the process. The problem you are trying to fix will
beunlikely to exist
> > if you follow a very well worn path.Let me add the following
suggestions
> > and forgive me if some of thesethings seem so trivial as to be
too obvious
> > to state.1. The final product accuracy will be dependent upon
the sum of
> > theerrors in each of the steps leading to the final product. i.e.
> > jig,templates, hot wiring, joining, glassing, filling.2. Get
your jig
> > right, and spend as much time on it as is needed toget the
desired level of
> > accuracy. Remember that a jig is a devicedesigned to permit
ordinary levels
> > of skill to achieve levels ofaccuracy higher than normally
possible. 3. Get
> > your hot wire templates spot on, make them as thin as
possibleand make sure
> > that they permit a smooth passage of the the hot wire.errors
come from
> > snagging wires, dragging drooping wires, cooling ofthe wires,
and hidden
> > obstructions. Why thin? remember that you are cutting a taper
and if you use
> > eachtemplate twice you will cut foam matching faces. Each face
will usethe
> > same face/edge of the template. One face/edge will be adjacent
tothe foam
> > but the other foam block will be spaced out by the thicknessof
the template
> > and will cut oversize. To better visualise this, thinkabout
cutting a
> > witches hat out of foam in two parts. Imagine a 1"thick template
halfway up
> > the hat. with the hat upright, the top halfwill use the top edge
of the
> > template. Cutting the bottom half willstill use the top edge of
the template
> > but the taper will mean thatthe wire meets the top of the foam
on an angle
> > and will cut over size. 4. Smooth passage of the wire means
smooth templates
> > and smoothoperators. 5. Snagging comes from :a. the nails
holding the
> > templates to the foam at an angle whichintersects the wire path
- so point
> > them inwards and locate them aninch or so from the cut
surface.b. the wire
> > hitting blobs of micro joining blocks prior to hot wiring- so
use very
> > little, and leave the edges free of micro ~ 1/4" or so.You can
fill this
> > gap later and there is no point in making thejoint any stronger
than the
> > parent foam. The foam is a mold, thestructure is the glass. 6.
Drooping
> > comes from wire lengthening, wire dragging and unevenheating and
poor
> > technique.7. When cutting the second half of a wing block put
the core
> > back intothe block from which you have just cut it.Some
suggestions : use
> > 0.032" stainless steel mig welding wire whichis orders of
magnitude
> > stronger than lockwire, use a good power supplywhich you can
control quickly
> > and easily, build a strong light hotwiresaw and heat and tighten
the wire
> > till your eyes bleed.. Plucking thewire will tell you when you
have reached
> > yield. Practice at different temps and speed until you get dogbone
> > freeshapes. This means slow on sharp curves, faster on shallow
curves,tight
> > hot wires and smooth accurate number following - at both ends.8.
> > Choreograph each cut before you make it and make sure the saw
canreach the
> > whole cut, the weights used to hold everything down can
becleared, and the
> > saw power supply cable is long enough - remember thatif you snag
you stop,
> > if you stop you burn and cut over size - sothe immediate action
if you snag
> > is out at right angles to the template.9. store your cores in
the cut out
> > portions.10 join the cores in the jig and run a straight edge
along
> > theleading edge to maximise alignment. Split differences and aim
to makeany
> > error a hollow rather than a hump.11. When glued remember this -
0.020" of
> > glass over corrugated ironwill not change the surface into an
ice rink so
> > sand your foam with along sanding block, a long straight edge
and along the
> > lines whichjoin the talking lines spanwise. Foam is much much
easier to sand
> > thaneither micro or glass. and get it to within 0.030" or so.
Use lightand
> > sand intelligently. One stroke of the sanding block will make
adifference.
> > Do not hard shell - this is a moronic process. Lets continue the
> > conversation when you get to glassing, there arelots of ways to
make that
> > simpler and easier as well. Hope this helpsJohn--- In
> > Q-LIST@... <Q-LIST%40yahoogroups.com>, "mtyquinn665"
> > <mquinn6@> wrote:>> I am trying VERY hard not to reinvent the
wheel but I
> > am attempting to > build the wing on a jig and see posting where
washout and
> > wing > alignment (of the foam) caused the final product to not
be as perfect
> > > as intended. (any sanding to match the other foam indicates an
> inacuracy
> > in following the template when hot wiring - then one sands to >
match and
> > you are left with an "original" airfoil)> > My thought is to
make a slot cut
> > (90 degrees perpendicular to the > surface) 1/2 inch deep at the
WL between
> > the foam sections and use a > 1/16" x 1" ( x width of the wing
at that point
> > minus 1 in or so) strip > of plastic as a key (this concept is
from years of
> > woodworking and what > we call "biskets"). > > To test for
levelness a equal
> > length wood skewer could be inserted > (using a small square to
insure
> > perpendicular to skin in 2 planes) > until it makes contact w/
the plastic
> > (prior to glassing)and a level > could be placed on top of the
skewers. > >
> > Does this make any sense?> > M.>
> >
> > __________________________________________________________
> > Climb to the top of the charts! Play Star Shuffle: the word
scramble
> > challenge with star power.
> >
http://club.live.com/star_shuffle.aspx?icid=starshuffle_wlmailtextlink_oct
> >
> >
> >
> >
> >
> >
>
> --
> Sam Hoskins
> www.MistakeProofing.Net
> www.MistakeProofing.net/blog/
> 618-967-0016 ph.
> 312-212-4086 fax
>
>
>
>
>
>
>
>
>
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>
>
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.503 / Virus Database: 269.15.31/1129 - Release Date:
13/11/2007 21:22
>
>
>
>






------------------------------------------------------------------------------


No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.5.503 / Virus Database: 269.15.32/1131 - Release Date:
14/11/2007 16:54


[Non-text portions of this message have been removed]


Michael Quinn
 

Paul,

I was actually going to build a "finish template" to determine how close the final profile is to the true airfoil. I see Johns point about how adding .0013 and .0009 layers can add up to a different final profile. I, however, do not think (I do not know) if John's start point in which he sands the foam accounts for this from a true LS1 or EP1212 profile (and how did he come up with that profile - b/c what I measured from what you sent me for the LS1 and what I have for the main wing EP1212 does NOT account for the lay-up of glass thickness!).

Does that mean that everyone that is currently flying with the LS1-Mod and have not done final sanding to a "finish template" have a LS1-Mod-mod profile (and same for the EP1212 main wing being a EP1212-mod)?

IF we were able to get people of flying Q planes to provide a sample of their final profile I would be interested in the results!

I am going with the hard shell method w/ everything I have read (esp. the straight fibers and ease of lay-up). I am also going to try (key word) to determine the thickness change of the glass lay-up and take that into consideration on the foam template ends (which I can see a big challenge due to the "drop off" of lay-up on the sparcap)... I read the GU canard is severly affected by even a painted leading edge or a single layer of duct tape on the leading edge making it vertually unflyable. The LS1 has less problems (so I read) - but it HAS to have some affect if it is not true to shape...

M.


To: Q-LIST@...: paulbuckley@...: Thu, 15 Nov 2007 11:13:06 +0000Subject: Re: [Q-LIST] Why hard shelling is a dumb idea

JohnWithout malice, I disagree with almost everything that you have said, except maybe the dust!It is quite obvious that you have never tried or seen this method, which is well documented.I reiterate that my wings are as perfect as they could possibly be, with virtually no micro filler, and that they only require a primer surfacer to finish.>>>> So the substrate has to be your very best work so do it once and do it right.<<<<Exactly!>>>> you have done far morework than you need to do, will most likely have a heavierwing and may have a less accurate product <<<<<Why more work? By all accounts, most builders spend an inordinate amount of time sanding-filling, sanding-filling, creating copious amounts of dust in the process.Why heavier? Using the hard shell method, most of the micro is sanded away and is only there to provide a straight, hard surface on which to lay the glass, the resultant cured surface of which is nigh on perfect.Why less accurate? You talk about sanding the bare, foam cores. Surely, doing that destroys any accuracy that you have tried to achieve by making accurate 'thin' templates!(and talking about your reasons for using a thin template is rather like saying that if your pitot head is on the port wing tip, turning left will give you an ASI reading that is lower than a right turn.No doubt it will, but it is both academic and unreadable)You talk about 'only a mechanical bond' between the glass and the hard shelled surface. Isn't virtually all of the airframe built relying on mechanical bonds? Have you ever tried to separate two mechanically bonded surfaces?The 'mechanical' bond is every bit as strong as any other bond on the airframe, which I believe holds together pretty well, provided, like everything else, it is done using the correct techniques.In any case, the weakest link in the 'skin to foam' bonding is the foam itself, and I have built test pieces (documented some time ago) using both methods of construction, and there was no discernable differencein the bonding strengths.>>>>>>Break though the shell whilst sanding and the foam is gone in aheartbeat - more repairs needed, more weight, more wait<<<<Rubbish! Are you going to use a belt sander??When sanding the shell, using a spline, you can clearly see when the micro is becoming thin, and that is when you stop.And as the foam cores have been accurately cut and jigged in the first place, there will be no high spots to break through!But even if you do break through, it is neither catastrophic or a problem.>>>>>And what shape do you finish the hard shell to? If you use the final finishtemplate (and there is is no other option) by definition when youfinish the construction process, you will be adding additionalmaterial unevenly on top of what you have tried to make the correctshape. Result? An inescapably incorrect shape. <<<<<<<Really John? I must have missed something. In my 24 years of being on the 'Quickie' scene, I have never yet seen a 'final finish' template.Have you? Has anyone?The hard shell is finished to the same shape as the underlying foam cores.Well, to 25thou. anyway! Hopefully, that is good enough!>>>>>>>>>And it gets worse. Now you have to sand the glass surface to dull tobond the micro, so off comes structural strength. The glass bundlesare not as straight as they could be and then we deliberately sandthrough them...<<<<<<<<<<Tell me John, do you not have to sand the glass wing surface in order to bond the micro filler when using the 'conventional' technique??Surely you are not advocating the use of peel ply over the whole wing area? It is a well know fact that doing so is a no-no because it adds a lot of weight..........And, using the hard shell method, it is easy to get the glass fibres dead straight......and I mean, dead straight!There is no doubt that you are a clever and intelligent man, John, but I think that you are neither practical or experienced in the building of glass fibre aeroplanes.You suffer from what a lot of engineers suffer from, the addiction to minutia.You are not building a Swiss watch.........I pay avid attention to detail and am a perfectionist, but you take your arguments beyond sensible reason and practicality.I could go on (and on and on) but I haven't the time or the patience.......if anyone would like to discuss the pros and cons I am available off list...... with lots of photos!Paul BuckleyCheshire EnglandTriQ-200Still building............----- Original Message ----- From: johntenhave To: Q-LIST@... Sent: Thursday, November 15, 2007 8:54 AMSubject: [Q-LIST] Why hard shelling is a dumb ideaOK, Paul before I go any further I am going to spell out the reasons why hardshelling is dumb and my comments are only directed at the method NOTat those who choose to use it. This is not a personal attack, pleasedo not take it as such. I am also not saying that you cannot get awing from using the process but rather that you have done far morework than you you need to do, will most likely have have a heavierwing and may have a less accurate product. For reasons I will expandupon in a moment you may well also finish up with an inferior level offinish.Firstly lets clearly define what we are trying to achieve:a smooth, straight, accurate, structurally efficient aerodynamically correct airfoil with the best possible finish in the shortest possibletime.The final shape is the outside. The outside is the resultant of (starting at the bottom surface) paint, primer surfacer, micro/filler,glass, glass foam interface, foam ...center line and then the sameseries in reverse. All of us only have so much sanding in us. Eventually the mostdiligent and persistent of us will give up and go fly so let me submitthat the smart thing to do is to spend that resource wisely.Finishing occurs at the point in a project when our physical,financial, energy and enthusiasm resources are at an ebb. Unfortunately, two factors conspire to get us. The first factor isthat the last thing we do is the first thing that everyone sees andunfortunately the total quality is often judged by the finish. Itbehooves us to get the finish to the highest possible standard (butnot at any cost or weight). What is the acceptable standard? Shortanswer - luxury car paint finish is a good standard to aim for. The second factor is that not everyone realises that the top coat isbest regarded as colour and shine on the substrate. Spraying 30microns of paint on a cheese grater will not transform it into amirror. So the substrate has to be your very best work so do it onceand do it right.Finishing is a progressive process. First flat, then increasinglysmooth. And there is a difference - a pool ball is smooth but it isnot flat, the billiard table is flat but it is not smooth. Polishingthe slate under the felt will not make the fabric finish any smoother.All the issues that Paul as identified as being rectified could andshould have been rectified by sanding the foam. Foam is much easierto sand than micro (we will get to glass in a moment). It is also ofuniform density so it sands evenly and quickly. You are subtractingweight. The process is fast, easy and you are working below the finalprofile.You are neither micro cure cycle time dependent nor faced with havingto spread, smooth, cure fill, sand, fill,each time adding weight,making dust. Break though the shell whilst sanding and the foam is gone in aheartbeat - more repairs needed, more weight, more wait. And whatshape do you finish the hard shell to? If you use the final finishtemplate (and there is is no other option) by definition when youfinish the construction process, you will be adding additionalmaterial unevenly on top of what you have tried to make the correctshape. Result? An inescapably incorrect shape. But that is not all.All that work and you have achieved a surface finish which isinappropriate and unnecessary for that stage in the finish. You have a surface which provides a poorer bond interface between theglass and the foam than the chemical and mechanical bond providedusing the original approach. More resin is then required to bond theglass to the micro surface and again it is only a mechanical bond. The glass bundles have a rigid under surface - which means that theydo finish up lying under and over to a greater degree than the wet onwet method combined with peel ply (which should be applied to everysquare inch of the surface.) The net result is that the glass surfaceis a raised mesh which is less securely bonded to the micro below andis located above the the correct profile.And it gets worse. Now you have to sand the glass surface to dull tobond the micro, so off comes structural strength. The glass bundlesare not as straight as they could be and then we deliberately sandthrough them...Lets summarise then.Hard shelling adds weight, is slower, results in the wrong profile,degrades bond strength between glass and foam, results in a weakerglass structure - and then you have to do it all again!! Remember thesanding effort is a finite resource and you have spent half of italready...Hardshelling makes as much sense as practice bleeding..Hope that explains the one liner a little more clearly..John--- In Q-LIST@..., "Paul Buckley" <paulbuckley@...> wrote:>> Me too!> > I actually aligned the two outer wing cores vertically on my bench,shearweb down, between two long straight edges which matched the taperof the wings, thus ensuring that the shearweb was flat and straight,as were all other joined surfaces. I also pinned the joint with shortwood dowels located on the level lines, but that isn't reallynecessary as you can simply lightly clamp two straight boards on eachside of the wing surfaces across the joint (as they are sittingvertically, on the shearweb), which will ensure that the panels arealigned accurately.> When cured both wings were then offered up to the center section,which was firmly fastened to the wing jig.> Result:- perfectly straight and aligned wings.> Easy peasy!> > As far as 'hard shelling' is concerned, I have made two sets ofwings this way, after building a set the 'wet' way.> It is much easier to make an accurate wing by 'hard shelling' withno bumps, hollows etc, and with the glass perfectly straight, with nomicro contamination between plies, and it is much quicker to lay theglass down on a previously prepared, smooth, surface, not to mentionbeing much less messy!> The only filling required on my wings were to fill the weave and theglass spar-cap 'steps', and I would never do it any other way, now.> Hardly a 'moronic' process!> > The glass bonds to the cured micro without any problems, and is justas strong as any other bonding providing that normal 'clean' buildingpractices are observed. (all of the airframe is glued together)> In any case, the weakest link is in the strength of the foam,whichever way you do it.> > Paul Buckley> Cheshire, England.> > Waddelow TriQ-200.....still building.> > > > ----- Original Message ----- > From: Sam Hoskins > To: Q-LIST@... > Sent: Thursday, November 15, 2007 12:26 AM> Subject: Re: [Q-LIST] Re: Initial foam alignment> > > Re your comment: "I am inclined to "build" the exterior BL 100-51) *to> center section (BL 51-0)* on a flat surface - let the micro dry.Then take> the two completed wings and butter up the center (at BL00) and allthe given> jigs "work" per the plans.."> > I did exactly that on the last wing I built and it was sooo mucheasier.> > Sam Hoskins> Murphysboro, IL> > On Nov 14, 2007 6:21 PM, Michael Quinn <mquinn6@...> wrote:> > >> > John, Everything makes sense after you do it... I just have notdone this> > before. I wish there was someone local to Charlotte that is afew steps> > ahead of me so I could work w/ them and learn - then mine wouldbe better by> > one generation of build experience! I think thru the processmany times> > before attacking it so that I can reduce the "damn I did it thehard way..."> > I am certain w/ pracitce/experience it will become easier. Ire-re-reread> > the plans and they talk about the jig - but the female jigs onlywere> > supporting one section of foam or the other (or are theybridging it?!?! - I> > have female jigs of 3/4 plywood (scared b/c of the which hatpotential since> > they are cut square and "should" only make contact with the wingin one> > point (lowest side of the wing). Do you micro and pin thejoints? I look at> > jigs from the picts sent to me from others and they look nothinglike the> > plans. I just am running thru the build process of the main wingand it goes> > like - check everything for fit and alignment - recheck this atleast 100> > times. assemble the center joint less than 1/16 gap (I do nothave the plans> > in front of me - but the purpose is for complete bond and reducethe risk of> > exothermic and melting foam and making a non bonded gap (yes?)). Ok,> > assuming gravity still is working in the downward direction -doesn't it> > make the center section of the main wing "want" to pull apart. Inoticed the> > 5min. epoxy between the foam and female jigs - assume that giveyou enough> > time to work the foam into final resting place after lathing -then it hold> > until the micro cures. Continuing on, the external two foam wingcores> > (already check fitted 100 times) are buttered with micro and putonto the> > assembly that I just completed (5 min. epoxy should hold itright?). Now -> > the female wing jig is on the center section (the plan show iton the> > external foam cores! this would change the angles of dihedraland make> > "curved" wings....), thus I scratch my brain (but not thru thenose)... If> > they are on the exterior part of the wing - I am inclined to"build" the> > exterior BL 100-51) *to center section (BL 51-0)* on a flatsurface - let> > the micro dry. Then take the two completed wings and butter upthe center> > (at BL00) and all the given jigs "work" per the plans....Hardshelling => > slathering and curing, sanding micro prior to starting to glass?I have read> > several success stories about this method - my fear is the lessthan optimum> > bond between the hardened micro and the glass lay-up. And weight(which the> > argument is you will have to use that micro on the outsideotherwise). Since> > one does not peel ply the micro (since it is sanded down totrue) - the last> > sanding would be done with 60 grit to leave connection points ofpure epoxy> > prior to glass. Please be gentile I am a virgin with regards to the> > quickie.... M. *Not certain on BL measurements - just pullingthese numbers> > from what I thought I remember reading...> >> > To: Q-LIST@... <Q-LIST%40yahoogroups.comFrom>:> > johntenhave@... <johntenhave%40yahoo.comDate>: Wed, 14 Nov 2007> > 08:25:38 +0000Subject: [Q-LIST] Re: Initial foam alignment> >> > M,you are attempting to partially fix one problem whilstignoring therest> > of the process. The problem you are trying to fix willbeunlikely to exist> > if you follow a very well worn path.Let me add the followingsuggestions> > and forgive me if some of thesethings seem so trivial as to betoo obvious> > to state.1. The final product accuracy will be dependent uponthe sum of> > theerrors in each of the steps leading to the final product. i.e.> > jig,templates, hot wiring, joining, glassing, filling.2. Getyour jig> > right, and spend as much time on it as is needed toget thedesired level of> > accuracy. Remember that a jig is a devicedesigned to permitordinary levels> > of skill to achieve levels ofaccuracy higher than normallypossible. 3. Get> > your hot wire templates spot on, make them as thin aspossibleand make sure> > that they permit a smooth passage of the the hot wire.errorscome from> > snagging wires, dragging drooping wires, cooling ofthe wires,and hidden> > obstructions. Why thin? remember that you are cutting a taperand if you use> > eachtemplate twice you will cut foam matching faces. Each facewill usethe> > same face/edge of the template. One face/edge will be adjacenttothe foam> > but the other foam block will be spaced out by the thicknessofthe template> > and will cut oversize. To better visualise this, thinkaboutcutting a> > witches hat out of foam in two parts. Imagine a 1"thick templatehalfway up> > the hat. with the hat upright, the top halfwill use the top edgeof the> > template. Cutting the bottom half willstill use the top edge ofthe template> > but the taper will mean thatthe wire meets the top of the foamon an angle> > and will cut over size. 4. Smooth passage of the wire meanssmooth templates> > and smoothoperators. 5. Snagging comes from :a. the nailsholding the> > templates to the foam at an angle whichintersects the wire path- so point> > them inwards and locate them aninch or so from the cutsurface.b. the wire> > hitting blobs of micro joining blocks prior to hot wiring- souse very> > little, and leave the edges free of micro ~ 1/4" or so.You canfill this> > gap later and there is no point in making thejoint any strongerthan the> > parent foam. The foam is a mold, thestructure is the glass. 6.Drooping> > comes from wire lengthening, wire dragging and unevenheating andpoor> > technique.7. When cutting the second half of a wing block putthe core> > back intothe block from which you have just cut it.Somesuggestions : use> > 0.032" stainless steel mig welding wire whichis orders of magnitude> > stronger than lockwire, use a good power supplywhich you cancontrol quickly> > and easily, build a strong light hotwiresaw and heat and tightenthe wire> > till your eyes bleed.. Plucking thewire will tell you when youhave reached> > yield. Practice at different temps and speed until you get dogbone> > freeshapes. This means slow on sharp curves, faster on shallowcurves,tight> > hot wires and smooth accurate number following - at both ends.8.> > Choreograph each cut before you make it and make sure the sawcanreach the> > whole cut, the weights used to hold everything down canbecleared, and the> > saw power supply cable is long enough - remember thatif you snagyou stop,> > if you stop you burn and cut over size - sothe immediate actionif you snag> > is out at right angles to the template.9. store your cores inthe cut out> > portions.10 join the cores in the jig and run a straight edge along> > theleading edge to maximise alignment. Split differences and aimto makeany> > error a hollow rather than a hump.11. When glued remember this -0.020" of> > glass over corrugated ironwill not change the surface into anice rink so> > sand your foam with along sanding block, a long straight edgeand along the> > lines whichjoin the talking lines spanwise. Foam is much mucheasier to sand> > thaneither micro or glass. and get it to within 0.030" or so.Use lightand> > sand intelligently. One stroke of the sanding block will makeadifference.> > Do not hard shell - this is a moronic process. Lets continue the> > conversation when you get to glassing, there arelots of ways tomake that> > simpler and easier as well. Hope this helpsJohn--- In> > Q-LIST@... <Q-LIST%40yahoogroups.com>, "mtyquinn665"> > <mquinn6@> wrote:>> I am trying VERY hard not to reinvent thewheel but I> > am attempting to > build the wing on a jig and see posting wherewashout and> > wing > alignment (of the foam) caused the final product to notbe as perfect> > > as intended. (any sanding to match the other foam indicates an> inacuracy> > in following the template when hot wiring - then one sands to >match and> > you are left with an "original" airfoil)> > My thought is tomake a slot cut> > (90 degrees perpendicular to the > surface) 1/2 inch deep at theWL between> > the foam sections and use a > 1/16" x 1" ( x width of the wingat that point> > minus 1 in or so) strip > of plastic as a key (this concept isfrom years of> > woodworking and what > we call "biskets"). > > To test forlevelness a equal> > length wood skewer could be inserted > (using a small square toinsure> > perpendicular to skin in 2 planes) > until it makes contact w/the plastic> > (prior to glassing)and a level > could be placed on top of theskewers. > >> > Does this make any sense?> > M.>> >> > __________________________________________________________> > Climb to the top of the charts! Play Star Shuffle: the word scramble> > challenge with star power.> >http://club.live.com/star_shuffle.aspx?icid=starshuffle_wlmailtextlink_oct> >> >> > [Non-text portions of this message have been removed]> >> > > >> > -- > Sam Hoskins> www.MistakeProofing.Net> www.MistakeProofing.net/blog/> 618-967-0016 ph.> 312-212-4086 fax> > [Non-text portions of this message have been removed]> > > > > > >----------------------------------------------------------> > > No virus found in this incoming message.> Checked by AVG Free Edition. > Version: 7.5.503 / Virus Database: 269.15.31/1129 - Release Date:13/11/2007 21:22> > > [Non-text portions of this message have been removed]>----------------------------------------------------------No virus found in this incoming message.Checked by AVG Free Edition. Version: 7.5.503 / Virus Database: 269.15.32/1131 - Release Date: 14/11/2007 16:54






_________________________________________________________________
Climb to the top of the charts!  Play Star Shuffle:  the word scramble challenge with star power.
http://club.live.com/star_shuffle.aspx?icid=starshuffle_wlmailtextlink_oct


Michael Quinn
 

Paul,

All this makes sense. I still think the bond between hardshell or micro-wet layup the weak point is between the micro (whether hard or wet) and not the rough sanded hard and glass. Yes the chemical bond on the wet lay-up will be stronger - but the chain is only as strong as the weakest link (whichever way and the foam).

The only way I see to make this better would be to take and put negative "teeth" in the foam with a nail every 1/2" (or so) to provide a better "bite" for the micro slurry to get into - IF you could be assured of getting down into the cavities. This of course would add weight.

Did you modify the original LS1 templates and EP1212 templates to account for the thickness of the glass layup? Or did you draw out the spar cap and sand down the foam where the thicker layers go? Good point about the final profile! I am curious how many true profiles after either technique are out there!!!

M.


To: Q-LIST@...: johntenhave@...: Thu, 15 Nov 2007 08:54:41 +0000Subject: [Q-LIST] Why hard shelling is a dumb idea

OK, Paul before I go any further I am going to spell out the reasons why hardshelling is dumb and my comments are only directed at the method NOTat those who choose to use it. This is not a personal attack, pleasedo not take it as such. I am also not saying that you cannot get awing from using the process but rather that you have done far morework than you you need to do, will most likely have have a heavierwing and may have a less accurate product. For reasons I will expandupon in a moment you may well also finish up with an inferior level offinish.Firstly lets clearly define what we are trying to achieve:a smooth, straight, accurate, structurally efficient aerodynamically correct airfoil with the best possible finish in the shortest possibletime.The final shape is the outside. The outside is the resultant of (starting at the bottom surface) paint, primer surfacer, micro/filler,glass, glass foam interface, foam ...center line and then the sameseries in reverse. All of us only have so much sanding in us. Eventually the mostdiligent and persistent of us will give up and go fly so let me submitthat the smart thing to do is to spend that resource wisely.Finishing occurs at the point in a project when our physical,financial, energy and enthusiasm resources are at an ebb. Unfortunately, two factors conspire to get us. The first factor isthat the last thing we do is the first thing that everyone sees andunfortunately the total quality is often judged by the finish. Itbehooves us to get the finish to the highest possible standard (butnot at any cost or weight). What is the acceptable standard? Shortanswer - luxury car paint finish is a good standard to aim for. The second factor is that not everyone realises that the top coat isbest regarded as colour and shine on the substrate. Spraying 30microns of paint on a cheese grater will not transform it into amirror. So the substrate has to be your very best work so do it onceand do it right.Finishing is a progressive process. First flat, then increasinglysmooth. And there is a difference - a pool ball is smooth but it isnot flat, the billiard table is flat but it is not smooth. Polishingthe slate under the felt will not make the fabric finish any smoother.All the issues that Paul as identified as being rectified could andshould have been rectified by sanding the foam. Foam is much easierto sand than micro (we will get to glass in a moment). It is also ofuniform density so it sands evenly and quickly. You are subtractingweight. The process is fast, easy and you are working below the finalprofile.You are neither micro cure cycle time dependent nor faced with havingto spread, smooth, cure fill, sand, fill,each time adding weight,making dust. Break though the shell whilst sanding and the foam is gone in aheartbeat - more repairs needed, more weight, more wait. And whatshape do you finish the hard shell to? If you use the final finishtemplate (and there is is no other option) by definition when youfinish the construction process, you will be adding additionalmaterial unevenly on top of what you have tried to make the correctshape. Result? An inescapably incorrect shape. But that is not all.All that work and you have achieved a surface finish which isinappropriate and unnecessary for that stage in the finish. You have a surface which provides a poorer bond interface between theglass and the foam than the chemical and mechanical bond providedusing the original approach. More resin is then required to bond theglass to the micro surface and again it is only a mechanical bond. The glass bundles have a rigid under surface - which means that theydo finish up lying under and over to a greater degree than the wet onwet method combined with peel ply (which should be applied to everysquare inch of the surface.) The net result is that the glass surfaceis a raised mesh which is less securely bonded to the micro below andis located above the the correct profile.And it gets worse. Now you have to sand the glass surface to dull tobond the micro, so off comes structural strength. The glass bundlesare not as straight as they could be and then we deliberately sandthrough them...Lets summarise then.Hard shelling adds weight, is slower, results in the wrong profile,degrades bond strength between glass and foam, results in a weakerglass structure - and then you have to do it all again!! Remember thesanding effort is a finite resource and you have spent half of italready...Hardshelling makes as much sense as practice bleeding..Hope that explains the one liner a little more clearly..John--- In Q-LIST@..., "Paul Buckley" <paulbuckley@...> wrote:>> Me too!> > I actually aligned the two outer wing cores vertically on my bench,shearweb down, between two long straight edges which matched the taperof the wings, thus ensuring that the shearweb was flat and straight,as were all other joined surfaces. I also pinned the joint with shortwood dowels located on the level lines, but that isn't reallynecessary as you can simply lightly clamp two straight boards on eachside of the wing surfaces across the joint (as they are sittingvertically, on the shearweb), which will ensure that the panels arealigned accurately.> When cured both wings were then offered up to the center section,which was firmly fastened to the wing jig.> Result:- perfectly straight and aligned wings.> Easy peasy!> > As far as 'hard shelling' is concerned, I have made two sets ofwings this way, after building a set the 'wet' way.> It is much easier to make an accurate wing by 'hard shelling' withno bumps, hollows etc, and with the glass perfectly straight, with nomicro contamination between plies, and it is much quicker to lay theglass down on a previously prepared, smooth, surface, not to mentionbeing much less messy!> The only filling required on my wings were to fill the weave and theglass spar-cap 'steps', and I would never do it any other way, now.> Hardly a 'moronic' process!> > The glass bonds to the cured micro without any problems, and is justas strong as any other bonding providing that normal 'clean' buildingpractices are observed. (all of the airframe is glued together)> In any case, the weakest link is in the strength of the foam,whichever way you do it.> > Paul Buckley> Cheshire, England.> > Waddelow TriQ-200.....still building.> > > > ----- Original Message ----- > From: Sam Hoskins > To: Q-LIST@... > Sent: Thursday, November 15, 2007 12:26 AM> Subject: Re: [Q-LIST] Re: Initial foam alignment> > > Re your comment: "I am inclined to "build" the exterior BL 100-51) *to> center section (BL 51-0)* on a flat surface - let the micro dry.Then take> the two completed wings and butter up the center (at BL00) and allthe given> jigs "work" per the plans.."> > I did exactly that on the last wing I built and it was sooo mucheasier.> > Sam Hoskins> Murphysboro, IL> > On Nov 14, 2007 6:21 PM, Michael Quinn <mquinn6@...> wrote:> > >> > John, Everything makes sense after you do it... I just have notdone this> > before. I wish there was someone local to Charlotte that is afew steps> > ahead of me so I could work w/ them and learn - then mine wouldbe better by> > one generation of build experience! I think thru the processmany times> > before attacking it so that I can reduce the "damn I did it thehard way..."> > I am certain w/ pracitce/experience it will become easier. Ire-re-reread> > the plans and they talk about the jig - but the female jigs onlywere> > supporting one section of foam or the other (or are theybridging it?!?! - I> > have female jigs of 3/4 plywood (scared b/c of the which hatpotential since> > they are cut square and "should" only make contact with the wingin one> > point (lowest side of the wing). Do you micro and pin thejoints? I look at> > jigs from the picts sent to me from others and they look nothinglike the> > plans. I just am running thru the build process of the main wingand it goes> > like - check everything for fit and alignment - recheck this atleast 100> > times. assemble the center joint less than 1/16 gap (I do nothave the plans> > in front of me - but the purpose is for complete bond and reducethe risk of> > exothermic and melting foam and making a non bonded gap (yes?)). Ok,> > assuming gravity still is working in the downward direction -doesn't it> > make the center section of the main wing "want" to pull apart. Inoticed the> > 5min. epoxy between the foam and female jigs - assume that giveyou enough> > time to work the foam into final resting place after lathing -then it hold> > until the micro cures. Continuing on, the external two foam wingcores> > (already check fitted 100 times) are buttered with micro and putonto the> > assembly that I just completed (5 min. epoxy should hold itright?). Now -> > the female wing jig is on the center section (the plan show iton the> > external foam cores! this would change the angles of dihedraland make> > "curved" wings....), thus I scratch my brain (but not thru thenose)... If> > they are on the exterior part of the wing - I am inclined to"build" the> > exterior BL 100-51) *to center section (BL 51-0)* on a flatsurface - let> > the micro dry. Then take the two completed wings and butter upthe center> > (at BL00) and all the given jigs "work" per the plans....Hardshelling => > slathering and curing, sanding micro prior to starting to glass?I have read> > several success stories about this method - my fear is the lessthan optimum> > bond between the hardened micro and the glass lay-up. And weight(which the> > argument is you will have to use that micro on the outsideotherwise). Since> > one does not peel ply the micro (since it is sanded down totrue) - the last> > sanding would be done with 60 grit to leave connection points ofpure epoxy> > prior to glass. Please be gentile I am a virgin with regards to the> > quickie.... M. *Not certain on BL measurements - just pullingthese numbers> > from what I thought I remember reading...> >> > To: Q-LIST@... <Q-LIST%40yahoogroups.comFrom>:> > johntenhave@... <johntenhave%40yahoo.comDate>: Wed, 14 Nov 2007> > 08:25:38 +0000Subject: [Q-LIST] Re: Initial foam alignment> >> > M,you are attempting to partially fix one problem whilstignoring therest> > of the process. The problem you are trying to fix willbeunlikely to exist> > if you follow a very well worn path.Let me add the followingsuggestions> > and forgive me if some of thesethings seem so trivial as to betoo obvious> > to state.1. The final product accuracy will be dependent uponthe sum of> > theerrors in each of the steps leading to the final product. i.e.> > jig,templates, hot wiring, joining, glassing, filling.2. Getyour jig> > right, and spend as much time on it as is needed toget thedesired level of> > accuracy. Remember that a jig is a devicedesigned to permitordinary levels> > of skill to achieve levels ofaccuracy higher than normallypossible. 3. Get> > your hot wire templates spot on, make them as thin aspossibleand make sure> > that they permit a smooth passage of the the hot wire.errorscome from> > snagging wires, dragging drooping wires, cooling ofthe wires,and hidden> > obstructions. Why thin? remember that you are cutting a taperand if you use> > eachtemplate twice you will cut foam matching faces. Each facewill usethe> > same face/edge of the template. One face/edge will be adjacenttothe foam> > but the other foam block will be spaced out by the thicknessofthe template> > and will cut oversize. To better visualise this, thinkaboutcutting a> > witches hat out of foam in two parts. Imagine a 1"thick templatehalfway up> > the hat. with the hat upright, the top halfwill use the top edgeof the> > template. Cutting the bottom half willstill use the top edge ofthe template> > but the taper will mean thatthe wire meets the top of the foamon an angle> > and will cut over size. 4. Smooth passage of the wire meanssmooth templates> > and smoothoperators. 5. Snagging comes from :a. the nailsholding the> > templates to the foam at an angle whichintersects the wire path- so point> > them inwards and locate them aninch or so from the cutsurface.b. the wire> > hitting blobs of micro joining blocks prior to hot wiring- souse very> > little, and leave the edges free of micro ~ 1/4" or so.You canfill this> > gap later and there is no point in making thejoint any strongerthan the> > parent foam. The foam is a mold, thestructure is the glass. 6.Drooping> > comes from wire lengthening, wire dragging and unevenheating andpoor> > technique.7. When cutting the second half of a wing block putthe core> > back intothe block from which you have just cut it.Somesuggestions : use> > 0.032" stainless steel mig welding wire whichis orders of magnitude> > stronger than lockwire, use a good power supplywhich you cancontrol quickly> > and easily, build a strong light hotwiresaw and heat and tightenthe wire> > till your eyes bleed.. Plucking thewire will tell you when youhave reached> > yield. Practice at different temps and speed until you get dogbone> > freeshapes. This means slow on sharp curves, faster on shallowcurves,tight> > hot wires and smooth accurate number following - at both ends.8.> > Choreograph each cut before you make it and make sure the sawcanreach the> > whole cut, the weights used to hold everything down canbecleared, and the> > saw power supply cable is long enough - remember thatif you snagyou stop,> > if you stop you burn and cut over size - sothe immediate actionif you snag> > is out at right angles to the template.9. store your cores inthe cut out> > portions.10 join the cores in the jig and run a straight edge along> > theleading edge to maximise alignment. Split differences and aimto makeany> > error a hollow rather than a hump.11. When glued remember this -0.020" of> > glass over corrugated ironwill not change the surface into anice rink so> > sand your foam with along sanding block, a long straight edgeand along the> > lines whichjoin the talking lines spanwise. Foam is much mucheasier to sand> > thaneither micro or glass. and get it to within 0.030" or so.Use lightand> > sand intelligently. One stroke of the sanding block will makeadifference.> > Do not hard shell - this is a moronic process. Lets continue the> > conversation when you get to glassing, there arelots of ways tomake that> > simpler and easier as well. Hope this helpsJohn--- In> > Q-LIST@... <Q-LIST%40yahoogroups.com>, "mtyquinn665"> > <mquinn6@> wrote:>> I am trying VERY hard not to reinvent thewheel but I> > am attempting to > build the wing on a jig and see posting wherewashout and> > wing > alignment (of the foam) caused the final product to notbe as perfect> > > as intended. (any sanding to match the other foam indicates an> inacuracy> > in following the template when hot wiring - then one sands to >match and> > you are left with an "original" airfoil)> > My thought is tomake a slot cut> > (90 degrees perpendicular to the > surface) 1/2 inch deep at theWL between> > the foam sections and use a > 1/16" x 1" ( x width of the wingat that point> > minus 1 in or so) strip > of plastic as a key (this concept isfrom years of> > woodworking and what > we call "biskets"). > > To test forlevelness a equal> > length wood skewer could be inserted > (using a small square toinsure> > perpendicular to skin in 2 planes) > until it makes contact w/the plastic> > (prior to glassing)and a level > could be placed on top of theskewers. > >> > Does this make any sense?> > M.>> >> > __________________________________________________________> > Climb to the top of the charts! Play Star Shuffle: the word scramble> > challenge with star power.> >http://club.live.com/star_shuffle.aspx?icid=starshuffle_wlmailtextlink_oct> >> >> > [Non-text portions of this message have been removed]> >> > > >> > -- > Sam Hoskins> www.MistakeProofing.Net> www.MistakeProofing.net/blog/> 618-967-0016 ph.> 312-212-4086 fax> > [Non-text portions of this message have been removed]> > > > > > >----------------------------------------------------------> > > No virus found in this incoming message.> Checked by AVG Free Edition. > Version: 7.5.503 / Virus Database: 269.15.31/1129 - Release Date:13/11/2007 21:22> > > [Non-text portions of this message have been removed]>






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Paul Buckley
 

Hi Mike

I find John Tenhave very irritating with his arrogant and patronising manner!
I know I shouldn't let it get to me (and I am not the first) and usually I don't, but this time it did!!
Sorry!
Comments below........

----- Original Message -----
From: Michael Quinn
To: q-list@...
Sent: Thursday, November 15, 2007 9:10 PM
Subject: RE: [Q-LIST] Why hard shelling is a dumb idea



Paul,

All this makes sense. I still think the bond between hardshell or micro-wet layup the weak point is between the micro (whether hard or wet) and not the rough sanded hard and glass. Yes the chemical bond on the wet lay-up will be stronger - but the chain is only as strong as the weakest link (whichever way and the foam). Exactly my point......I can see where the argument is coming from, but the perceived problem simply does not exist.

The only way I see to make this better would be to take and put negative "teeth" in the foam with a nail every 1/2" (or so) to provide a better "bite" for the micro slurry to get into - IF you could be assured of getting down into the cavities. This of course would add weight. Yes, it would, but the original foam was orange and had a larger cell size than the blue. This, it was originally claimed, made for a better 'peel' strength. However, builders have been using the blue variety for years now, with no adverse problems. If it worries you, why not make an indentation tool out of a small cog wheel, and run it along the foam? Quicker than using a nail.

Did you modify the original LS1 templates and EP1212 templates to account for the thickness of the glass layup? Or did you draw out the spar cap and sand down the foam where the thicker layers go? Good point about the final profile! I am curious how many true profiles after either technique are out there!!! No, and I know of no one who has. I don't even know if the original templates were drawn to allow for the glass, but I seriously doubt it. Modifying them would add an inordinate amount of work, and for what? Why do it when so many Quickies are flying successfully without any thought being given to it?
The airfoils are tapered so if you want to make a 'final profile' template it will only fit in one place along the span. What about the rest of the wing? Are you going to make one for every foot or so? I don't think so, but that doesn't mean that I think that some sort of profile template, for a particular spot, wouldn't be a bad idea.
There are several reasons why I think that 'hard shelling' is a better way to go and not one of the 'reasons' that John came up with has convinced me otherwise.
I really don't think that he can see the wood for the trees and does not think in a practical way!
However, I am not saying that everyone should build their wings the 'hard shell' way, it is a matter of assessment and personal choice.
I, personally, assessed it (from experience) and made my choice. I would, now, never make wing any other way...I think that the method is far superior BUT, I do not expect everyone to agree with me and I certainly will not stop talking to you if you decide to go the 'wet' way!

Kind regards

Paul
M.


To: Q-LIST@...: johntenhave@...: Thu, 15 Nov 2007 08:54:41 +0000Subject: [Q-LIST] Why hard shelling is a dumb idea




OK, Paul before I go any further I am going to spell out the reasons why hardshelling is dumb and my comments are only directed at the method NOTat those who choose to use it. This is not a personal attack, pleasedo not take it as such. I am also not saying that you cannot get awing from using the process but rather that you have done far morework than you you need to do, will most likely have have a heavierwing and may have a less accurate product. For reasons I will expandupon in a moment you may well also finish up with an inferior level offinish.Firstly lets clearly define what we are trying to achieve:a smooth, straight, accurate, structurally efficient aerodynamically correct airfoil with the best possible finish in the shortest possibletime.The final shape is the outside. The outside is the resultant of (starting at the bottom surface) paint, primer surfacer, micro/filler,glass, glass foam interface, foam ...center line and then the sameseries in reverse. All of us only have so much sanding in us. Eventually the mostdiligent and persistent of us will give up and go fly so let me submitthat the smart thing to do is to spend that resource wisely.Finishing occurs at the point in a project when our physical,financial, energy and enthusiasm resources are at an ebb. Unfortunately, two factors conspire to get us. The first factor isthat the last thing we do is the first thing that everyone sees andunfortunately the total quality is often judged by the finish. Itbehooves us to get the finish to the highest possible standard (butnot at any cost or weight). What is the acceptable standard? Shortanswer - luxury car paint finish is a good standard to aim for. The second factor is that not everyone realises that the top coat isbest regarded as colour and shine on the substrate. Spraying 30microns of paint on a cheese grater will not transform it into amirror. So the substrate has to be your very best work so do it onceand do it right.Finishing is a progressive process. First flat, then increasinglysmooth. And there is a difference - a pool ball is smooth but it isnot flat, the billiard table is flat but it is not smooth. Polishingthe slate under the felt will not make the fabric finish any smoother.All the issues that Paul as identified as being rectified could andshould have been rectified by sanding the foam. Foam is much easierto sand than micro (we will get to glass in a moment). It is also ofuniform density so it sands evenly and quickly. You are subtractingweight. The process is fast, easy and you are working below the finalprofile.You are neither micro cure cycle time dependent nor faced with havingto spread, smooth, cure fill, sand, fill,each time adding weight,making dust. Break though the shell whilst sanding and the foam is gone in aheartbeat - more repairs needed, more weight, more wait. And whatshape do you finish the hard shell to? If you use the final finishtemplate (and there is is no other option) by definition when youfinish the construction process, you will be adding additionalmaterial unevenly on top of what you have tried to make the correctshape. Result? An inescapably incorrect shape. But that is not all.All that work and you have achieved a surface finish which isinappropriate and unnecessary for that stage in the finish. You have a surface which provides a poorer bond interface between theglass and the foam than the chemical and mechanical bond providedusing the original approach. More resin is then required to bond theglass to the micro surface and again it is only a mechanical bond. The glass bundles have a rigid under surface - which means that theydo finish up lying under and over to a greater degree than the wet onwet method combined with peel ply (which should be applied to everysquare inch of the surface.) The net result is that the glass surfaceis a raised mesh which is less securely bonded to the micro below andis located above the the correct profile.And it gets worse. Now you have to sand the glass surface to dull tobond the micro, so off comes structural strength. The glass bundlesare not as straight as they could be and then we deliberately sandthrough them...Lets summarise then.Hard shelling adds weight, is slower, results in the wrong profile,degrades bond strength between glass and foam, results in a weakerglass structure - and then you have to do it all again!! Remember thesanding effort is a finite resource and you have spent half of italready...Hardshelling makes as much sense as practice bleeding..Hope that explains the one liner a little more clearly..John--- In Q-LIST@..., "Paul Buckley" <paulbuckley@...> wrote:>> Me too!> > I actually aligned the two outer wing cores vertically on my bench,shearweb down, between two long straight edges which matched the taperof the wings, thus ensuring that the shearweb was flat and straight,as were all other joined surfaces. I also pinned the joint with shortwood dowels located on the level lines, but that isn't reallynecessary as you can simply lightly clamp two straight boards on eachside of the wing surfaces across the joint (as they are sittingvertically, on the shearweb), which will ensure that the panels arealigned accurately.> When cured both wings were then offered up to the center section,which was firmly fastened to the wing jig.> Result:- perfectly straight and aligned wings.> Easy peasy!> > As far as 'hard shelling' is concerned, I have made two sets ofwings this way, after building a set the 'wet' way.> It is much easier to make an accurate wing by 'hard shelling' withno bumps, hollows etc, and with the glass perfectly straight, with nomicro contamination between plies, and it is much quicker to lay theglass down on a previously prepared, smooth, surface, not to mentionbeing much less messy!> The only filling required on my wings were to fill the weave and theglass spar-cap 'steps', and I would never do it any other way, now.> Hardly a 'moronic' process!> > The glass bonds to the cured micro without any problems, and is justas strong as any other bonding providing that normal 'clean' buildingpractices are observed. (all of the airframe is glued together)> In any case, the weakest link is in the strength of the foam,whichever way you do it.> > Paul Buckley> Cheshire, England.> > Waddelow TriQ-200.....still building.> > > > ----- Original Message ----- > From: Sam Hoskins > To: Q-LIST@... > Sent: Thursday, November 15, 2007 12:26 AM> Subject: Re: [Q-LIST] Re: Initial foam alignment> > > Re your comment: "I am inclined to "build" the exterior BL 100-51) *to> center section (BL 51-0)* on a flat surface - let the micro dry.Then take> the two completed wings and butter up the center (at BL00) and allthe given> jigs "work" per the plans.."> > I did exactly that on the last wing I built and it was sooo mucheasier.> > Sam Hoskins> Murphysboro, IL> > On Nov 14, 2007 6:21 PM, Michael Quinn <mquinn6@...> wrote:> > >> > John, Everything makes sense after you do it... I just have notdone this> > before. I wish there was someone local to Charlotte that is afew steps> > ahead of me so I could work w/ them and learn - then mine wouldbe better by> > one generation of build experience! I think thru the processmany times> > before attacking it so that I can reduce the "damn I did it thehard way..."> > I am certain w/ pracitce/experience it will become easier. Ire-re-reread> > the plans and they talk about the jig - but the female jigs onlywere> > supporting one section of foam or the other (or are theybridging it?!?! - I> > have female jigs of 3/4 plywood (scared b/c of the which hatpotential since> > they are cut square and "should" only make contact with the wingin one> > point (lowest side of the wing). Do you micro and pin thejoints? I look at> > jigs from the picts sent to me from others and they look nothinglike the> > plans. I just am running thru the build process of the main wingand it goes> > like - check everything for fit and alignment - recheck this atleast 100> > times. assemble the center joint less than 1/16 gap (I do nothave the plans> > in front of me - but the purpose is for complete bond and reducethe risk of> > exothermic and melting foam and making a non bonded gap (yes?)). Ok,> > assuming gravity still is working in the downward direction -doesn't it> > make the center section of the main wing "want" to pull apart. Inoticed the> > 5min. epoxy between the foam and female jigs - assume that giveyou enough> > time to work the foam into final resting place after lathing -then it hold> > until the micro cures. Continuing on, the external two foam wingcores> > (already check fitted 100 times) are buttered with micro and putonto the> > assembly that I just completed (5 min. epoxy should hold itright?). Now -> > the female wing jig is on the center section (the plan show iton the> > external foam cores! this would change the angles of dihedraland make> > "curved" wings....), thus I scratch my brain (but not thru thenose)... If> > they are on the exterior part of the wing - I am inclined to"build" the> > exterior BL 100-51) *to center section (BL 51-0)* on a flatsurface - let> > the micro dry. Then take the two completed wings and butter upthe center> > (at BL00) and all the given jigs "work" per the plans....Hardshelling => > slathering and curing, sanding micro prior to starting to glass?I have read> > several success stories about this method - my fear is the lessthan optimum> > bond between the hardened micro and the glass lay-up. And weight(which the> > argument is you will have to use that micro on the outsideotherwise). Since> > one does not peel ply the micro (since it is sanded down totrue) - the last> > sanding would be done with 60 grit to leave connection points ofpure epoxy> > prior to glass. Please be gentile I am a virgin with regards to the> > quickie.... M. *Not certain on BL measurements - just pullingthese numbers> > from what I thought I remember reading...> >> > To: Q-LIST@... <Q-LIST%40yahoogroups.comFrom>:> > johntenhave@... <johntenhave%40yahoo.comDate>: Wed, 14 Nov 2007> > 08:25:38 +0000Subject: [Q-LIST] Re: Initial foam alignment> >> > M,you are attempting to partially fix one problem whilstignoring therest> > of the process. The problem you are trying to fix willbeunlikely to exist> > if you follow a very well worn path.Let me add the followingsuggestions> > and forgive me if some of thesethings seem so trivial as to betoo obvious> > to state.1. The final product accuracy will be dependent uponthe sum of> > theerrors in each of the steps leading to the final product. i.e.> > jig,templates, hot wiring, joining, glassing, filling.2. Getyour jig> > right, and spend as much time on it as is needed toget thedesired level of> > accuracy. Remember that a jig is a devicedesigned to permitordinary levels> > of skill to achieve levels ofaccuracy higher than normallypossible. 3. Get> > your hot wire templates spot on, make them as thin aspossibleand make sure> > that they permit a smooth passage of the the hot wire.errorscome from> > snagging wires, dragging drooping wires, cooling ofthe wires,and hidden> > obstructions. Why thin? remember that you are cutting a taperand if you use> > eachtemplate twice you will cut foam matching faces. Each facewill usethe> > same face/edge of the template. One face/edge will be adjacenttothe foam> > but the other foam block will be spaced out by the thicknessofthe template> > and will cut oversize. To better visualise this, thinkaboutcutting a> > witches hat out of foam in two parts. Imagine a 1"thick templatehalfway up> > the hat. with the hat upright, the top halfwill use the top edgeof the> > template. Cutting the bottom half willstill use the top edge ofthe template> > but the taper will mean thatthe wire meets the top of the foamon an angle> > and will cut over size. 4. Smooth passage of the wire meanssmooth templates> > and smoothoperators. 5. Snagging comes from :a. the nailsholding the> > templates to the foam at an angle whichintersects the wire path- so point> > them inwards and locate them aninch or so from the cutsurface.b. the wire> > hitting blobs of micro joining blocks prior to hot wiring- souse very> > little, and leave the edges free of micro ~ 1/4" or so.You canfill this> > gap later and there is no point in making thejoint any strongerthan the> > parent foam. The foam is a mold, thestructure is the glass. 6.Drooping> > comes from wire lengthening, wire dragging and unevenheating andpoor> > technique.7. When cutting the second half of a wing block putthe core> > back intothe block from which you have just cut it.Somesuggestions : use> > 0.032" stainless steel mig welding wire whichis orders of magnitude> > stronger than lockwire, use a good power supplywhich you cancontrol quickly> > and easily, build a strong light hotwiresaw and heat and tightenthe wire> > till your eyes bleed.. Plucking thewire will tell you when youhave reached> > yield. Practice at different temps and speed until you get dogbone> > freeshapes. This means slow on sharp curves, faster on shallowcurves,tight> > hot wires and smooth accurate number following - at both ends.8.> > Choreograph each cut before you make it and make sure the sawcanreach the> > whole cut, the weights used to hold everything down canbecleared, and the> > saw power supply cable is long enough - remember thatif you snagyou stop,> > if you stop you burn and cut over size - sothe immediate actionif you snag> > is out at right angles to the template.9. store your cores inthe cut out> > portions.10 join the cores in the jig and run a straight edge along> > theleading edge to maximise alignment. Split differences and aimto makeany> > error a hollow rather than a hump.11. When glued remember this -0.020" of> > glass over corrugated ironwill not change the surface into anice rink so> > sand your foam with along sanding block, a long straight edgeand along the> > lines whichjoin the talking lines spanwise. Foam is much mucheasier to sand> > thaneither micro or glass. and get it to within 0.030" or so.Use lightand> > sand intelligently. One stroke of the sanding block will makeadifference.> > Do not hard shell - this is a moronic process. Lets continue the> > conversation when you get to glassing, there arelots of ways tomake that> > simpler and easier as well. Hope this helpsJohn--- In> > Q-LIST@... <Q-LIST%40yahoogroups.com>, "mtyquinn665"> > <mquinn6@> wrote:>> I am trying VERY hard not to reinvent thewheel but I> > am attempting to > build the wing on a jig and see posting wherewashout and> > wing > alignment (of the foam) caused the final product to notbe as perfect> > > as intended. (any sanding to match the other foam indicates an> inacuracy> > in following the template when hot wiring - then one sands to >match and> > you are left with an "original" airfoil)> > My thought is tomake a slot cut> > (90 degrees perpendicular to the > surface) 1/2 inch deep at theWL between> > the foam sections and use a > 1/16" x 1" ( x width of the wingat that point> > minus 1 in or so) strip > of plastic as a key (this concept isfrom years of> > woodworking and what > we call "biskets"). > > To test forlevelness a equal> > length wood skewer could be inserted > (using a small square toinsure> > perpendicular to skin in 2 planes) > until it makes contact w/the plastic> > (prior to glassing)and a level > could be placed on top of theskewers. > >> > Does this make any sense?> > M.>> >> > __________________________________________________________> > Climb to the top of the charts! Play Star Shuffle: the word scramble> > challenge with star power.> >http://club.live.com/star_shuffle.aspx?icid=starshuffle_wlmailtextlink_oct> >> >> > [Non-text portions of this message have been removed]> >> > > >> > -- > Sam Hoskins> www.MistakeProofing.Net> www.MistakeProofing.net/blog/> 618-967-0016 ph.> 312-212-4086 fax> > > > > > > > >----------------------------------------------------------> > > No virus found in this incoming message.> Checked by AVG Free Edition. > Version: 7.5.503 / Virus Database: 269.15.31/1129 - Release Date:13/11/2007 21:22> > > >






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Quickie Builders Association WEB site
http://www.quickiebuilders.org


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Dave Dugas
 

John,

Could you post some pictures of your Q? Dave D.

johntenhave <johntenhave@...> wrote:
Paul,

no offence taken, and there is nothing like a healthy, reasoned debate.

Rather than clutter the bandwidth, let your comments stand. Let me
comment briefly on incorrect assumptions and may I direct you and
anyone else how is interested to the composite finishing presentation
I have posted. I was asked to explain to the SAAA how the finish on VH
XMX was achieved, so I did.

A Long Ez has 195 sq ft of wetted area. All of it has to be finished
from foam to paint. A Q2XX is a much smaller, simpler area subset.

I have seen the hardshelling method and you are right - I have not
tried it. Its shortcomings were apparent by inspection, my teachers
(mentioned in the presentation) were masters of the faster method and
that is how I decided which was best.

Yes I am advocating peel plying every square inch of the external and
internal glass work. I will explain my reasoning why in another
posting- if it is not apparent from the presentation.

Regards

John

P.S. Re practical experience? I built and surface finished the Long
Ez used as the example in the presentation - single handed.

As one wry Vari Eze builder once noted : "more like moderately
f**king difficult!"

--- In Q-LIST@..., "Paul Buckley" <paulbuckley@...> wrote:

John

Without malice, I disagree with almost everything that you have
said, except maybe the dust!

It is quite obvious that you have never tried or seen this method,
which is well documented.

I reiterate that my wings are as perfect as they could possibly be,
with virtually no micro filler, and that they only require a primer
surfacer to finish.

So the substrate has to be your very best work so do it once
and do it right.<<<<

Exactly!

you have done far more
work than you need to do, will most likely have a heavier
wing and may have a less accurate product <<<<<

Why more work? By all accounts, most builders spend an inordinate
amount of time sanding-filling, sanding-filling, creating copious
amounts of dust in the process.

Why heavier? Using the hard shell method, most of the micro is
sanded away and is only there to provide a straight, hard surface on
which to lay the glass, the resultant cured surface of which is nigh
on perfect.

Why less accurate? You talk about sanding the bare, foam cores.
Surely, doing that destroys any accuracy that you have tried to
achieve by making accurate 'thin' templates!
(and talking about your reasons for using a thin template is rather
like saying that if your pitot head is on the port wing tip, turning
left will give you an ASI reading that is lower than a right turn.
No doubt it will, but it is both academic and unreadable)

You talk about 'only a mechanical bond' between the glass and the
hard shelled surface. Isn't virtually all of the airframe built
relying on mechanical bonds? Have you ever tried to separate two
mechanically bonded surfaces?
The 'mechanical' bond is every bit as strong as any other bond on
the airframe, which I believe holds together pretty well, provided,
like everything else, it is done using the correct techniques.
In any case, the weakest link in the 'skin to foam' bonding is the
foam itself, and I have built test pieces (documented some time ago)
using both methods of construction, and there was no discernable
difference
in the bonding strengths.

Break though the shell whilst sanding and the foam is gone in a
heartbeat - more repairs needed, more weight, more wait<<<<

Rubbish! Are you going to use a belt sander??
When sanding the shell, using a spline, you can clearly see when the
micro is becoming thin, and that is when you stop.
And as the foam cores have been accurately cut and jigged in the
first place, there will be no high spots to break through!
But even if you do break through, it is neither catastrophic or a
problem.

And what shape do you finish the hard shell to? If you use the
final finish
template (and there is is no other option) by definition when you
finish the construction process, you will be adding additional
material unevenly on top of what you have tried to make the correct
shape. Result? An inescapably incorrect shape. <<<<<<<

Really John? I must have missed something. In my 24 years of being
on the 'Quickie' scene, I have never yet seen a 'final finish' template.
Have you? Has anyone?
The hard shell is finished to the same shape as the underlying foam
cores.
Well, to 25thou. anyway! Hopefully, that is good enough!

And it gets worse. Now you have to sand the glass surface
to dull to
bond the micro, so off comes structural strength. The glass bundles
are not as straight as they could be and then we deliberately sand
through them...<<<<<<<<<<

Tell me John, do you not have to sand the glass wing surface in
order to bond the micro filler when using the 'conventional' technique??
Surely you are not advocating the use of peel ply over the whole
wing area? It is a well know fact that doing so is a no-no because it
adds a lot of weight..........
And, using the hard shell method, it is easy to get the glass fibres
dead straight......and I mean, dead straight!

There is no doubt that you are a clever and intelligent man, John,
but I think that you are neither practical or experienced in the
building of glass fibre aeroplanes.
You suffer from what a lot of engineers suffer from, the addiction
to minutia.
You are not building a Swiss watch.........I pay avid attention to
detail and am a perfectionist, but you take your arguments beyond
sensible reason and practicality.

I could go on (and on and on) but I haven't the time or the
patience.......if anyone would like to discuss the pros and cons I am
available off list...... with lots of photos!

Paul Buckley
Cheshire
England

TriQ-200
Still building............





----- Original Message -----
From: johntenhave
To: Q-LIST@...
Sent: Thursday, November 15, 2007 8:54 AM
Subject: [Q-LIST] Why hard shelling is a dumb idea


OK, Paul

before I go any further I am going to spell out the reasons why hard
shelling is dumb and my comments are only directed at the method NOT
at those who choose to use it. This is not a personal attack, please
do not take it as such. I am also not saying that you cannot get a
wing from using the process but rather that you have done far more
work than you you need to do, will most likely have have a heavier
wing and may have a less accurate product. For reasons I will expand
upon in a moment you may well also finish up with an inferior level of
finish.

Firstly lets clearly define what we are trying to achieve:

a smooth, straight, accurate, structurally efficient aerodynamically
correct airfoil with the best possible finish in the shortest possible
time.

The final shape is the outside. The outside is the resultant of (
starting at the bottom surface) paint, primer surfacer, micro/filler
,glass, glass foam interface, foam ...center line and then the same
series in reverse.

All of us only have so much sanding in us. Eventually the most
diligent and persistent of us will give up and go fly so let me submit
that the smart thing to do is to spend that resource wisely.

Finishing occurs at the point in a project when our physical,
financial, energy and enthusiasm resources are at an ebb.
Unfortunately, two factors conspire to get us. The first factor is
that the last thing we do is the first thing that everyone sees and
unfortunately the total quality is often judged by the finish. It
behooves us to get the finish to the highest possible standard (but
not at any cost or weight). What is the acceptable standard? Short
answer - luxury car paint finish is a good standard to aim for.

The second factor is that not everyone realises that the top coat is
best regarded as colour and shine on the substrate. Spraying 30
microns of paint on a cheese grater will not transform it into a
mirror. So the substrate has to be your very best work so do it once
and do it right.

Finishing is a progressive process. First flat, then increasingly
smooth. And there is a difference - a pool ball is smooth but it is
not flat, the billiard table is flat but it is not smooth. Polishing
the slate under the felt will not make the fabric finish any smoother.

All the issues that Paul as identified as being rectified could and
should have been rectified by sanding the foam. Foam is much easier
to sand than micro (we will get to glass in a moment). It is also of
uniform density so it sands evenly and quickly. You are subtracting
weight. The process is fast, easy and you are working below the final
profile.

You are neither micro cure cycle time dependent nor faced with having
to spread, smooth, cure fill, sand, fill,each time adding weight,
making dust.

Break though the shell whilst sanding and the foam is gone in a
heartbeat - more repairs needed, more weight, more wait. And what
shape do you finish the hard shell to? If you use the final finish
template (and there is is no other option) by definition when you
finish the construction process, you will be adding additional
material unevenly on top of what you have tried to make the correct
shape. Result? An inescapably incorrect shape.

But that is not all.

All that work and you have achieved a surface finish which is
inappropriate and unnecessary for that stage in the finish.

You have a surface which provides a poorer bond interface between the
glass and the foam than the chemical and mechanical bond provided
using the original approach. More resin is then required to bond the
glass to the micro surface and again it is only a mechanical bond.

The glass bundles have a rigid under surface - which means that they
do finish up lying under and over to a greater degree than the wet on
wet method combined with peel ply (which should be applied to every
square inch of the surface.) The net result is that the glass surface
is a raised mesh which is less securely bonded to the micro below and
is located above the the correct profile.

And it gets worse. Now you have to sand the glass surface to dull to
bond the micro, so off comes structural strength. The glass bundles
are not as straight as they could be and then we deliberately sand
through them...

Lets summarise then.

Hard shelling adds weight, is slower, results in the wrong profile,
degrades bond strength between glass and foam, results in a weaker
glass structure - and then you have to do it all again!! Remember the
sanding effort is a finite resource and you have spent half of it
already...

Hardshelling makes as much sense as practice bleeding..

Hope that explains the one liner a little more clearly..

John


--- In Q-LIST@..., "Paul Buckley" <paulbuckley@> wrote:

Me too!

I actually aligned the two outer wing cores vertically on my bench,
shearweb down, between two long straight edges which matched the taper
of the wings, thus ensuring that the shearweb was flat and straight,
as were all other joined surfaces. I also pinned the joint with short
wood dowels located on the level lines, but that isn't really
necessary as you can simply lightly clamp two straight boards on each
side of the wing surfaces across the joint (as they are sitting
vertically, on the shearweb), which will ensure that the panels are
aligned accurately.
When cured both wings were then offered up to the center section,
which was firmly fastened to the wing jig.
Result:- perfectly straight and aligned wings.
Easy peasy!

As far as 'hard shelling' is concerned, I have made two sets of
wings this way, after building a set the 'wet' way.
It is much easier to make an accurate wing by 'hard shelling' with
no bumps, hollows etc, and with the glass perfectly straight, with no
micro contamination between plies, and it is much quicker to lay the
glass down on a previously prepared, smooth, surface, not to mention
being much less messy!
The only filling required on my wings were to fill the weave and the
glass spar-cap 'steps', and I would never do it any other way, now.
Hardly a 'moronic' process!

The glass bonds to the cured micro without any problems, and is just
as strong as any other bonding providing that normal 'clean' building
practices are observed. (all of the airframe is glued together)
In any case, the weakest link is in the strength of the foam,
whichever way you do it.

Paul Buckley
Cheshire, England.

Waddelow TriQ-200.....still building.



----- Original Message -----
From: Sam Hoskins
To: Q-LIST@...
Sent: Thursday, November 15, 2007 12:26 AM
Subject: Re: [Q-LIST] Re: Initial foam alignment


Re your comment: "I am inclined to "build" the exterior BL
100-51) *to
center section (BL 51-0)* on a flat surface - let the micro dry.
Then take
the two completed wings and butter up the center (at BL00) and all
the given
jigs "work" per the plans.."

I did exactly that on the last wing I built and it was sooo much
easier.

Sam Hoskins
Murphysboro, IL

On Nov 14, 2007 6:21 PM, Michael Quinn <mquinn6@> wrote:


John, Everything makes sense after you do it... I just have not
done this
before. I wish there was someone local to Charlotte that is a
few steps
ahead of me so I could work w/ them and learn - then mine would
be better by
one generation of build experience! I think thru the process
many times
before attacking it so that I can reduce the "damn I did it the
hard way..."
I am certain w/ pracitce/experience it will become easier. I
re-re-reread
the plans and they talk about the jig - but the female jigs only
were
supporting one section of foam or the other (or are they
bridging it?!?! - I
have female jigs of 3/4 plywood (scared b/c of the which hat
potential since
they are cut square and "should" only make contact with the wing
in one
point (lowest side of the wing). Do you micro and pin the
joints? I look at
jigs from the picts sent to me from others and they look nothing
like the
plans. I just am running thru the build process of the main wing
and it goes
like - check everything for fit and alignment - recheck this at
least 100
times. assemble the center joint less than 1/16 gap (I do not
have the plans
in front of me - but the purpose is for complete bond and reduce
the risk of
exothermic and melting foam and making a non bonded gap
(yes?)). Ok,
assuming gravity still is working in the downward direction -
doesn't it
make the center section of the main wing "want" to pull apart. I
noticed the
5min. epoxy between the foam and female jigs - assume that give
you enough
time to work the foam into final resting place after lathing -
then it hold
until the micro cures. Continuing on, the external two foam wing
cores
(already check fitted 100 times) are buttered with micro and put
onto the
assembly that I just completed (5 min. epoxy should hold it
right?). Now -
the female wing jig is on the center section (the plan show it
on the
external foam cores! this would change the angles of dihedral
and make
"curved" wings....), thus I scratch my brain (but not thru the
nose)... If
they are on the exterior part of the wing - I am inclined to
"build" the
exterior BL 100-51) *to center section (BL 51-0)* on a flat
surface - let
the micro dry. Then take the two completed wings and butter up
the center
(at BL00) and all the given jigs "work" per the plans....
Hardshelling =
slathering and curing, sanding micro prior to starting to glass?
I have read
several success stories about this method - my fear is the less
than optimum
bond between the hardened micro and the glass lay-up. And weight
(which the
argument is you will have to use that micro on the outside
otherwise). Since
one does not peel ply the micro (since it is sanded down to
true) - the last
sanding would be done with 60 grit to leave connection points of
pure epoxy
prior to glass. Please be gentile I am a virgin with regards
to the
quickie.... M. *Not certain on BL measurements - just pulling
these numbers
from what I thought I remember reading...

To: Q-LIST@ <Q-LIST%40yahoogroups.comFrom>:
johntenhave@ <johntenhave%40yahoo.comDate>: Wed, 14 Nov 2007
08:25:38 +0000Subject: [Q-LIST] Re: Initial foam alignment

M,you are attempting to partially fix one problem whilst
ignoring therest
of the process. The problem you are trying to fix will
beunlikely to exist
if you follow a very well worn path.Let me add the following
suggestions
and forgive me if some of thesethings seem so trivial as to be
too obvious
to state.1. The final product accuracy will be dependent upon
the sum of
theerrors in each of the steps leading to the final product. i.e.
jig,templates, hot wiring, joining, glassing, filling.2. Get
your jig
right, and spend as much time on it as is needed toget the
desired level of
accuracy. Remember that a jig is a devicedesigned to permit
ordinary levels
of skill to achieve levels ofaccuracy higher than normally
possible. 3. Get
your hot wire templates spot on, make them as thin as
possibleand make sure
that they permit a smooth passage of the the hot wire.errors
come from
snagging wires, dragging drooping wires, cooling ofthe wires,
and hidden
obstructions. Why thin? remember that you are cutting a taper
and if you use
eachtemplate twice you will cut foam matching faces. Each face
will usethe
same face/edge of the template. One face/edge will be adjacent
tothe foam
but the other foam block will be spaced out by the thicknessof
the template
and will cut oversize. To better visualise this, thinkabout
cutting a
witches hat out of foam in two parts. Imagine a 1"thick template
halfway up
the hat. with the hat upright, the top halfwill use the top edge
of the
template. Cutting the bottom half willstill use the top edge of
the template
but the taper will mean thatthe wire meets the top of the foam
on an angle
and will cut over size. 4. Smooth passage of the wire means
smooth templates
and smoothoperators. 5. Snagging comes from :a. the nails
holding the
templates to the foam at an angle whichintersects the wire path
- so point
them inwards and locate them aninch or so from the cut
surface.b. the wire
hitting blobs of micro joining blocks prior to hot wiring- so
use very
little, and leave the edges free of micro ~ 1/4" or so.You can
fill this
gap later and there is no point in making thejoint any stronger
than the
parent foam. The foam is a mold, thestructure is the glass. 6.
Drooping
comes from wire lengthening, wire dragging and unevenheating and
poor
technique.7. When cutting the second half of a wing block put
the core
back intothe block from which you have just cut it.Some
suggestions : use
0.032" stainless steel mig welding wire whichis orders of
magnitude
stronger than lockwire, use a good power supplywhich you can
control quickly
and easily, build a strong light hotwiresaw and heat and tighten
the wire
till your eyes bleed.. Plucking thewire will tell you when you
have reached
yield. Practice at different temps and speed until you get dogbone
freeshapes. This means slow on sharp curves, faster on shallow
curves,tight
hot wires and smooth accurate number following - at both ends.8.
Choreograph each cut before you make it and make sure the saw
canreach the
whole cut, the weights used to hold everything down can
becleared, and the
saw power supply cable is long enough - remember thatif you snag
you stop,
if you stop you burn and cut over size - sothe immediate action
if you snag
is out at right angles to the template.9. store your cores in
the cut out
portions.10 join the cores in the jig and run a straight edge
along
theleading edge to maximise alignment. Split differences and aim
to makeany
error a hollow rather than a hump.11. When glued remember this -
0.020" of
glass over corrugated ironwill not change the surface into an
ice rink so
sand your foam with along sanding block, a long straight edge
and along the
lines whichjoin the talking lines spanwise. Foam is much much
easier to sand
thaneither micro or glass. and get it to within 0.030" or so.
Use lightand
sand intelligently. One stroke of the sanding block will make
adifference.
Do not hard shell - this is a moronic process. Lets continue the
conversation when you get to glassing, there arelots of ways to
make that
simpler and easier as well. Hope this helpsJohn--- In
Q-LIST@... <Q-LIST%40yahoogroups.com>, "mtyquinn665"
<mquinn6@> wrote:>> I am trying VERY hard not to reinvent the
wheel but I
am attempting to > build the wing on a jig and see posting where
washout and
wing > alignment (of the foam) caused the final product to not
be as perfect
as intended. (any sanding to match the other foam indicates an
inacuracy
in following the template when hot wiring - then one sands to >
match and
you are left with an "original" airfoil)> > My thought is to
make a slot cut
(90 degrees perpendicular to the > surface) 1/2 inch deep at the
WL between
the foam sections and use a > 1/16" x 1" ( x width of the wing
at that point
minus 1 in or so) strip > of plastic as a key (this concept is
from years of
woodworking and what > we call "biskets"). > > To test for
levelness a equal
length wood skewer could be inserted > (using a small square to
insure
perpendicular to skin in 2 planes) > until it makes contact w/
the plastic
(prior to glassing)and a level > could be placed on top of the
skewers. > >
Does this make any sense?> > M.>

__________________________________________________________
Climb to the top of the charts! Play Star Shuffle: the word
scramble
challenge with star power.
http://club.live.com/star_shuffle.aspx?icid=starshuffle_wlmailtextlink_oct





--
Sam Hoskins
www.MistakeProofing.Net
www.MistakeProofing.net/blog/
618-967-0016 ph.
312-212-4086 fax








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---------------------------------
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John ten
 

Sure,

check the presentation I posted this morning in the files section.

John

--- In Q-LIST@..., Dave Dugas <davedq2@...> wrote:

John,

Could you post some pictures of your Q? Dave D.

johntenhave <johntenhave@...> wrote:
Paul,

no offence taken, and there is nothing like a healthy, reasoned debate.

Rather than clutter the bandwidth, let your comments stand. Let me
comment briefly on incorrect assumptions and may I direct you and
anyone else how is interested to the composite finishing presentation
I have posted. I was asked to explain to the SAAA how the finish on VH
XMX was achieved, so I did.

A Long Ez has 195 sq ft of wetted area. All of it has to be finished
from foam to paint. A Q2XX is a much smaller, simpler area subset.

I have seen the hardshelling method and you are right - I have not
tried it. Its shortcomings were apparent by inspection, my teachers
(mentioned in the presentation) were masters of the faster method and
that is how I decided which was best.

Yes I am advocating peel plying every square inch of the external and
internal glass work. I will explain my reasoning why in another
posting- if it is not apparent from the presentation.

Regards

John

P.S. Re practical experience? I built and surface finished the Long
Ez used as the example in the presentation - single handed.

As one wry Vari Eze builder once noted : "more like moderately
f**king difficult!"

--- In Q-LIST@..., "Paul Buckley" <paulbuckley@> wrote:

John

Without malice, I disagree with almost everything that you have
said, except maybe the dust!

It is quite obvious that you have never tried or seen this method,
which is well documented.

I reiterate that my wings are as perfect as they could possibly be,
with virtually no micro filler, and that they only require a primer
surfacer to finish.

So the substrate has to be your very best work so do it once
and do it right.<<<<

Exactly!

you have done far more
work than you need to do, will most likely have a heavier
wing and may have a less accurate product <<<<<

Why more work? By all accounts, most builders spend an inordinate
amount of time sanding-filling, sanding-filling, creating copious
amounts of dust in the process.

Why heavier? Using the hard shell method, most of the micro is
sanded away and is only there to provide a straight, hard surface on
which to lay the glass, the resultant cured surface of which is nigh
on perfect.

Why less accurate? You talk about sanding the bare, foam cores.
Surely, doing that destroys any accuracy that you have tried to
achieve by making accurate 'thin' templates!
(and talking about your reasons for using a thin template is rather
like saying that if your pitot head is on the port wing tip, turning
left will give you an ASI reading that is lower than a right turn.
No doubt it will, but it is both academic and unreadable)

You talk about 'only a mechanical bond' between the glass and the
hard shelled surface. Isn't virtually all of the airframe built
relying on mechanical bonds? Have you ever tried to separate two
mechanically bonded surfaces?
The 'mechanical' bond is every bit as strong as any other bond on
the airframe, which I believe holds together pretty well, provided,
like everything else, it is done using the correct techniques.
In any case, the weakest link in the 'skin to foam' bonding is the
foam itself, and I have built test pieces (documented some time ago)
using both methods of construction, and there was no discernable
difference
in the bonding strengths.

Break though the shell whilst sanding and the foam is gone in a
heartbeat - more repairs needed, more weight, more wait<<<<

Rubbish! Are you going to use a belt sander??
When sanding the shell, using a spline, you can clearly see when the
micro is becoming thin, and that is when you stop.
And as the foam cores have been accurately cut and jigged in the
first place, there will be no high spots to break through!
But even if you do break through, it is neither catastrophic or a
problem.

And what shape do you finish the hard shell to? If you use the
final finish
template (and there is is no other option) by definition when you
finish the construction process, you will be adding additional
material unevenly on top of what you have tried to make the correct
shape. Result? An inescapably incorrect shape. <<<<<<<

Really John? I must have missed something. In my 24 years of being
on the 'Quickie' scene, I have never yet seen a 'final finish' template.
Have you? Has anyone?
The hard shell is finished to the same shape as the underlying foam
cores.
Well, to 25thou. anyway! Hopefully, that is good enough!

And it gets worse. Now you have to sand the glass surface
to dull to
bond the micro, so off comes structural strength. The glass bundles
are not as straight as they could be and then we deliberately sand
through them...<<<<<<<<<<

Tell me John, do you not have to sand the glass wing surface in
order to bond the micro filler when using the 'conventional' technique??
Surely you are not advocating the use of peel ply over the whole
wing area? It is a well know fact that doing so is a no-no because it
adds a lot of weight..........
And, using the hard shell method, it is easy to get the glass fibres
dead straight......and I mean, dead straight!

There is no doubt that you are a clever and intelligent man, John,
but I think that you are neither practical or experienced in the
building of glass fibre aeroplanes.
You suffer from what a lot of engineers suffer from, the addiction
to minutia.
You are not building a Swiss watch.........I pay avid attention to
detail and am a perfectionist, but you take your arguments beyond
sensible reason and practicality.

I could go on (and on and on) but I haven't the time or the
patience.......if anyone would like to discuss the pros and cons I am
available off list...... with lots of photos!

Paul Buckley
Cheshire
England

TriQ-200
Still building............





----- Original Message -----
From: johntenhave
To: Q-LIST@...
Sent: Thursday, November 15, 2007 8:54 AM
Subject: [Q-LIST] Why hard shelling is a dumb idea


OK, Paul

before I go any further I am going to spell out the reasons why hard
shelling is dumb and my comments are only directed at the method NOT
at those who choose to use it. This is not a personal attack, please
do not take it as such. I am also not saying that you cannot get a
wing from using the process but rather that you have done far more
work than you you need to do, will most likely have have a heavier
wing and may have a less accurate product. For reasons I will expand
upon in a moment you may well also finish up with an inferior level of
finish.

Firstly lets clearly define what we are trying to achieve:

a smooth, straight, accurate, structurally efficient aerodynamically
correct airfoil with the best possible finish in the shortest possible
time.

The final shape is the outside. The outside is the resultant of (
starting at the bottom surface) paint, primer surfacer, micro/filler
,glass, glass foam interface, foam ...center line and then the same
series in reverse.

All of us only have so much sanding in us. Eventually the most
diligent and persistent of us will give up and go fly so let me submit
that the smart thing to do is to spend that resource wisely.

Finishing occurs at the point in a project when our physical,
financial, energy and enthusiasm resources are at an ebb.
Unfortunately, two factors conspire to get us. The first factor is
that the last thing we do is the first thing that everyone sees and
unfortunately the total quality is often judged by the finish. It
behooves us to get the finish to the highest possible standard (but
not at any cost or weight). What is the acceptable standard? Short
answer - luxury car paint finish is a good standard to aim for.

The second factor is that not everyone realises that the top coat is
best regarded as colour and shine on the substrate. Spraying 30
microns of paint on a cheese grater will not transform it into a
mirror. So the substrate has to be your very best work so do it once
and do it right.

Finishing is a progressive process. First flat, then increasingly
smooth. And there is a difference - a pool ball is smooth but it is
not flat, the billiard table is flat but it is not smooth. Polishing
the slate under the felt will not make the fabric finish any smoother.

All the issues that Paul as identified as being rectified could and
should have been rectified by sanding the foam. Foam is much easier
to sand than micro (we will get to glass in a moment). It is also of
uniform density so it sands evenly and quickly. You are subtracting
weight. The process is fast, easy and you are working below the final
profile.

You are neither micro cure cycle time dependent nor faced with having
to spread, smooth, cure fill, sand, fill,each time adding weight,
making dust.

Break though the shell whilst sanding and the foam is gone in a
heartbeat - more repairs needed, more weight, more wait. And what
shape do you finish the hard shell to? If you use the final finish
template (and there is is no other option) by definition when you
finish the construction process, you will be adding additional
material unevenly on top of what you have tried to make the correct
shape. Result? An inescapably incorrect shape.

But that is not all.

All that work and you have achieved a surface finish which is
inappropriate and unnecessary for that stage in the finish.

You have a surface which provides a poorer bond interface between the
glass and the foam than the chemical and mechanical bond provided
using the original approach. More resin is then required to bond the
glass to the micro surface and again it is only a mechanical bond.

The glass bundles have a rigid under surface - which means that they
do finish up lying under and over to a greater degree than the wet on
wet method combined with peel ply (which should be applied to every
square inch of the surface.) The net result is that the glass surface
is a raised mesh which is less securely bonded to the micro below and
is located above the the correct profile.

And it gets worse. Now you have to sand the glass surface to dull to
bond the micro, so off comes structural strength. The glass bundles
are not as straight as they could be and then we deliberately sand
through them...

Lets summarise then.

Hard shelling adds weight, is slower, results in the wrong profile,
degrades bond strength between glass and foam, results in a weaker
glass structure - and then you have to do it all again!! Remember the
sanding effort is a finite resource and you have spent half of it
already...

Hardshelling makes as much sense as practice bleeding..

Hope that explains the one liner a little more clearly..

John


--- In Q-LIST@..., "Paul Buckley" <paulbuckley@> wrote:

Me too!

I actually aligned the two outer wing cores vertically on my bench,
shearweb down, between two long straight edges which matched the taper
of the wings, thus ensuring that the shearweb was flat and straight,
as were all other joined surfaces. I also pinned the joint with short
wood dowels located on the level lines, but that isn't really
necessary as you can simply lightly clamp two straight boards on each
side of the wing surfaces across the joint (as they are sitting
vertically, on the shearweb), which will ensure that the panels are
aligned accurately.
When cured both wings were then offered up to the center section,
which was firmly fastened to the wing jig.
Result:- perfectly straight and aligned wings.
Easy peasy!

As far as 'hard shelling' is concerned, I have made two sets of
wings this way, after building a set the 'wet' way.
It is much easier to make an accurate wing by 'hard shelling' with
no bumps, hollows etc, and with the glass perfectly straight, with no
micro contamination between plies, and it is much quicker to lay the
glass down on a previously prepared, smooth, surface, not to mention
being much less messy!
The only filling required on my wings were to fill the weave and the
glass spar-cap 'steps', and I would never do it any other way, now.
Hardly a 'moronic' process!

The glass bonds to the cured micro without any problems, and is just
as strong as any other bonding providing that normal 'clean' building
practices are observed. (all of the airframe is glued together)
In any case, the weakest link is in the strength of the foam,
whichever way you do it.

Paul Buckley
Cheshire, England.

Waddelow TriQ-200.....still building.



----- Original Message -----
From: Sam Hoskins
To: Q-LIST@...
Sent: Thursday, November 15, 2007 12:26 AM
Subject: Re: [Q-LIST] Re: Initial foam alignment


Re your comment: "I am inclined to "build" the exterior BL
100-51) *to
center section (BL 51-0)* on a flat surface - let the micro dry.
Then take
the two completed wings and butter up the center (at BL00) and all
the given
jigs "work" per the plans.."

I did exactly that on the last wing I built and it was sooo much
easier.

Sam Hoskins
Murphysboro, IL

On Nov 14, 2007 6:21 PM, Michael Quinn <mquinn6@> wrote:


John, Everything makes sense after you do it... I just have not
done this
before. I wish there was someone local to Charlotte that is a
few steps
ahead of me so I could work w/ them and learn - then mine would
be better by
one generation of build experience! I think thru the process
many times
before attacking it so that I can reduce the "damn I did it the
hard way..."
I am certain w/ pracitce/experience it will become easier. I
re-re-reread
the plans and they talk about the jig - but the female jigs only
were
supporting one section of foam or the other (or are they
bridging it?!?! - I
have female jigs of 3/4 plywood (scared b/c of the which hat
potential since
they are cut square and "should" only make contact with the wing
in one
point (lowest side of the wing). Do you micro and pin the
joints? I look at
jigs from the picts sent to me from others and they look nothing
like the
plans. I just am running thru the build process of the main wing
and it goes
like - check everything for fit and alignment - recheck this at
least 100
times. assemble the center joint less than 1/16 gap (I do not
have the plans
in front of me - but the purpose is for complete bond and reduce
the risk of
exothermic and melting foam and making a non bonded gap
(yes?)). Ok,
assuming gravity still is working in the downward direction -
doesn't it
make the center section of the main wing "want" to pull apart. I
noticed the
5min. epoxy between the foam and female jigs - assume that give
you enough
time to work the foam into final resting place after lathing -
then it hold
until the micro cures. Continuing on, the external two foam wing
cores
(already check fitted 100 times) are buttered with micro and put
onto the
assembly that I just completed (5 min. epoxy should hold it
right?). Now -
the female wing jig is on the center section (the plan show it
on the
external foam cores! this would change the angles of dihedral
and make
"curved" wings....), thus I scratch my brain (but not thru the
nose)... If
they are on the exterior part of the wing - I am inclined to
"build" the
exterior BL 100-51) *to center section (BL 51-0)* on a flat
surface - let
the micro dry. Then take the two completed wings and butter up
the center
(at BL00) and all the given jigs "work" per the plans....
Hardshelling =
slathering and curing, sanding micro prior to starting to glass?
I have read
several success stories about this method - my fear is the less
than optimum
bond between the hardened micro and the glass lay-up. And weight
(which the
argument is you will have to use that micro on the outside
otherwise). Since
one does not peel ply the micro (since it is sanded down to
true) - the last
sanding would be done with 60 grit to leave connection points of
pure epoxy
prior to glass. Please be gentile I am a virgin with regards
to the
quickie.... M. *Not certain on BL measurements - just pulling
these numbers
from what I thought I remember reading...

To: Q-LIST@ <Q-LIST%40yahoogroups.comFrom>:
johntenhave@ <johntenhave%40yahoo.comDate>: Wed, 14 Nov 2007
08:25:38 +0000Subject: [Q-LIST] Re: Initial foam alignment

M,you are attempting to partially fix one problem whilst
ignoring therest
of the process. The problem you are trying to fix will
beunlikely to exist
if you follow a very well worn path.Let me add the following
suggestions
and forgive me if some of thesethings seem so trivial as to be
too obvious
to state.1. The final product accuracy will be dependent upon
the sum of
theerrors in each of the steps leading to the final product. i.e.
jig,templates, hot wiring, joining, glassing, filling.2. Get
your jig
right, and spend as much time on it as is needed toget the
desired level of
accuracy. Remember that a jig is a devicedesigned to permit
ordinary levels
of skill to achieve levels ofaccuracy higher than normally
possible. 3. Get
your hot wire templates spot on, make them as thin as
possibleand make sure
that they permit a smooth passage of the the hot wire.errors
come from
snagging wires, dragging drooping wires, cooling ofthe wires,
and hidden
obstructions. Why thin? remember that you are cutting a taper
and if you use
eachtemplate twice you will cut foam matching faces. Each face
will usethe
same face/edge of the template. One face/edge will be adjacent
tothe foam
but the other foam block will be spaced out by the thicknessof
the template
and will cut oversize. To better visualise this, thinkabout
cutting a
witches hat out of foam in two parts. Imagine a 1"thick template
halfway up
the hat. with the hat upright, the top halfwill use the top edge
of the
template. Cutting the bottom half willstill use the top edge of
the template
but the taper will mean thatthe wire meets the top of the foam
on an angle
and will cut over size. 4. Smooth passage of the wire means
smooth templates
and smoothoperators. 5. Snagging comes from :a. the nails
holding the
templates to the foam at an angle whichintersects the wire path
- so point
them inwards and locate them aninch or so from the cut
surface.b. the wire
hitting blobs of micro joining blocks prior to hot wiring- so
use very
little, and leave the edges free of micro ~ 1/4" or so.You can
fill this
gap later and there is no point in making thejoint any stronger
than the
parent foam. The foam is a mold, thestructure is the glass. 6.
Drooping
comes from wire lengthening, wire dragging and unevenheating and
poor
technique.7. When cutting the second half of a wing block put
the core
back intothe block from which you have just cut it.Some
suggestions : use
0.032" stainless steel mig welding wire whichis orders of
magnitude
stronger than lockwire, use a good power supplywhich you can
control quickly
and easily, build a strong light hotwiresaw and heat and tighten
the wire
till your eyes bleed.. Plucking thewire will tell you when you
have reached
yield. Practice at different temps and speed until you get dogbone
freeshapes. This means slow on sharp curves, faster on shallow
curves,tight
hot wires and smooth accurate number following - at both ends.8.
Choreograph each cut before you make it and make sure the saw
canreach the
whole cut, the weights used to hold everything down can
becleared, and the
saw power supply cable is long enough - remember thatif you snag
you stop,
if you stop you burn and cut over size - sothe immediate action
if you snag
is out at right angles to the template.9. store your cores in
the cut out
portions.10 join the cores in the jig and run a straight edge
along
theleading edge to maximise alignment. Split differences and aim
to makeany
error a hollow rather than a hump.11. When glued remember this -
0.020" of
glass over corrugated ironwill not change the surface into an
ice rink so
sand your foam with along sanding block, a long straight edge
and along the
lines whichjoin the talking lines spanwise. Foam is much much
easier to sand
thaneither micro or glass. and get it to within 0.030" or so.
Use lightand
sand intelligently. One stroke of the sanding block will make
adifference.
Do not hard shell - this is a moronic process. Lets continue the
conversation when you get to glassing, there arelots of ways to
make that
simpler and easier as well. Hope this helpsJohn--- In
Q-LIST@... <Q-LIST%40yahoogroups.com>, "mtyquinn665"
<mquinn6@> wrote:>> I am trying VERY hard not to reinvent the
wheel but I
am attempting to > build the wing on a jig and see posting where
washout and
wing > alignment (of the foam) caused the final product to not
be as perfect
as intended. (any sanding to match the other foam indicates an
inacuracy
in following the template when hot wiring - then one sands to >
match and
you are left with an "original" airfoil)> > My thought is to
make a slot cut
(90 degrees perpendicular to the > surface) 1/2 inch deep at the
WL between
the foam sections and use a > 1/16" x 1" ( x width of the wing
at that point
minus 1 in or so) strip > of plastic as a key (this concept is
from years of
woodworking and what > we call "biskets"). > > To test for
levelness a equal
length wood skewer could be inserted > (using a small square to
insure
perpendicular to skin in 2 planes) > until it makes contact w/
the plastic
(prior to glassing)and a level > could be placed on top of the
skewers. > >
Does this make any sense?> > M.>

__________________________________________________________
Climb to the top of the charts! Play Star Shuffle: the word
scramble
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--
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www.MistakeProofing.Net
www.MistakeProofing.net/blog/
618-967-0016 ph.
312-212-4086 fax








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---------------------------------
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[Non-text portions of this message have been removed]


Allan Farr
 

Paul. John T H knows what he is talking about and I (for one) appreciate his very detailed expert posts.
Allan F

----- Original Message -----
From: Paul Buckley
To: Q-LIST@...
Sent: Friday, 16 November 2007 11:43
Subject: Re: [Q-LIST] Why hard shelling is a dumb idea


Hi Mike

I find John Tenhave very irritating with his arrogant and patronising manner!
I know I shouldn't let it get to me (and I am not the first) and usually I don't, but this time it did!!
Sorry!
Comments below........
----- Original Message -----
From: Michael Quinn
To: q-list@...
Sent: Thursday, November 15, 2007 9:10 PM
Subject: RE: [Q-LIST] Why hard shelling is a dumb idea



Paul,

All this makes sense. I still think the bond between hardshell or micro-wet layup the weak point is between the micro (whether hard or wet) and not the rough sanded hard and glass. Yes the chemical bond on the wet lay-up will be stronger - but the chain is only as strong as the weakest link (whichever way and the foam). Exactly my point......I can see where the argument is coming from, but the perceived problem simply does not exist.

The only way I see to make this better would be to take and put negative "teeth" in the foam with a nail every 1/2" (or so) to provide a better "bite" for the micro slurry to get into - IF you could be assured of getting down into the cavities. This of course would add weight. Yes, it would, but the original foam was orange and had a larger cell size than the blue. This, it was originally claimed, made for a better 'peel' strength. However, builders have been using the blue variety for years now, with no adverse problems. If it worries you, why not make an indentation tool out of a small cog wheel, and run it along the foam? Quicker than using a nail.

Did you modify the original LS1 templates and EP1212 templates to account for the thickness of the glass layup? Or did you draw out the spar cap and sand down the foam where the thicker layers go? Good point about the final profile! I am curious how many true profiles after either technique are out there!!! No, and I know of no one who has. I don't even know if the original templates were drawn to allow for the glass, but I seriously doubt it. Modifying them would add an inordinate amount of work, and for what? Why do it when so many Quickies are flying successfully without any thought being given to it?
The airfoils are tapered so if you want to make a 'final profile' template it will only fit in one place along the span. What about the rest of the wing? Are you going to make one for every foot or so? I don't think so, but that doesn't mean that I think that some sort of profile template, for a particular spot, wouldn't be a bad idea.
There are several reasons why I think that 'hard shelling' is a better way to go and not one of the 'reasons' that John came up with has convinced me otherwise.
I really don't think that he can see the wood for the trees and does not think in a practical way!
However, I am not saying that everyone should build their wings the 'hard shell' way, it is a matter of assessment and personal choice.
I, personally, assessed it (from experience) and made my choice. I would, now, never make wing any other way...I think that the method is far superior BUT, I do not expect everyone to agree with me and I certainly will not stop talking to you if you decide to go the 'wet' way!

Kind regards

Paul
M.


To: Q-LIST@...: johntenhave@...: Thu, 15 Nov 2007 08:54:41 +0000Subject: [Q-LIST] Why hard shelling is a dumb idea




OK, Paul before I go any further I am going to spell out the reasons why hardshelling is dumb and my comments are only directed at the method NOTat those who choose to use it. This is not a personal attack, pleasedo not take it as such. I am also not saying that you cannot get awing from using the process but rather that you have done far morework than you you need to do, will most likely have have a heavierwing and may have a less accurate product. For reasons I will expandupon in a moment you may well also finish up with an inferior level offinish.Firstly lets clearly define what we are trying to achieve:a smooth, straight, accurate, structurally efficient aerodynamically correct airfoil with the best possible finish in the shortest possibletime.The final shape is the outside. The outside is the resultant of (starting at the bottom surface) paint, primer surfacer, micro/filler,glass, glass foam interface, foam ...center line and then the sameseries in reverse. All of us only have so much sanding in us. Eventually the mostdiligent and persistent of us will give up and go fly so let me submitthat the smart thing to do is to spend that resource wisely.Finishing occurs at the point in a project when our physical,financial, energy and enthusiasm resources are at an ebb. Unfortunately, two factors conspire to get us. The first factor isthat the last thing we do is the first thing that everyone sees andunfortunately the total quality is often judged by the finish. Itbehooves us to get the finish to the highest possible standard (butnot at any cost or weight). What is the acceptable standard? Shortanswer - luxury car paint finish is a good standard to aim for. The second factor is that not everyone realises that the top coat isbest regarded as colour and shine on the substrate. Spraying 30microns of paint on a cheese grater will not transform it into amirror. So the substrate has to be your very best work so do it onceand do it right.Finishing is a progressive process. First flat, then increasinglysmooth. And there is a difference - a pool ball is smooth but it isnot flat, the billiard table is flat but it is not smooth. Polishingthe slate under the felt will not make the fabric finish any smoother.All the issues that Paul as identified as being rectified could andshould have been rectified by sanding the foam. Foam is much easierto sand than micro (we will get to glass in a moment). It is also ofuniform density so it sands evenly and quickly. You are subtractingweight. The process is fast, easy and you are working below the finalprofile.You are neither micro cure cycle time dependent nor faced with havingto spread, smooth, cure fill, sand, fill,each time adding weight,making dust. Break though the shell whilst sanding and the foam is gone in aheartbeat - more repairs needed, more weight, more wait. And whatshape do you finish the hard shell to? If you use the final finishtemplate (and there is is no other option) by definition when youfinish the construction process, you will be adding additionalmaterial unevenly on top of what you have tried to make the correctshape. Result? An inescapably incorrect shape. But that is not all.All that work and you have achieved a surface finish which isinappropriate and unnecessary for that stage in the finish. You have a surface which provides a poorer bond interface between theglass and the foam than the chemical and mechanical bond providedusing the original approach. More resin is then required to bond theglass to the micro surface and again it is only a mechanical bond. The glass bundles have a rigid under surface - which means that theydo finish up lying under and over to a greater degree than the wet onwet method combined with peel ply (which should be applied to everysquare inch of the surface.) The net result is that the glass surfaceis a raised mesh which is less securely bonded to the micro below andis located above the the correct profile.And it gets worse. Now you have to sand the glass surface to dull tobond the micro, so off comes structural strength. The glass bundlesare not as straight as they could be and then we deliberately sandthrough them...Lets summarise then.Hard shelling adds weight, is slower, results in the wrong profile,degrades bond strength between glass and foam, results in a weakerglass structure - and then you have to do it all again!! Remember thesanding effort is a finite resource and you have spent half of italready...Hardshelling makes as much sense as practice bleeding..Hope that explains the one liner a little more clearly..John--- In Q-LIST@..., "Paul Buckley" <paulbuckley@...> wrote:>> Me too!> > I actually aligned the two outer wing cores vertically on my bench,shearweb down, between two long straight edges which matched the taperof the wings, thus ensuring that the shearweb was flat and straight,as were all other joined surfaces. I also pinned the joint with shortwood dowels located on the level lines, but that isn't reallynecessary as you can simply lightly clamp two straight boards on eachside of the wing surfaces across the joint (as they are sittingvertically, on the shearweb), which will ensure that the panels arealigned accurately.> When cured both wings were then offered up to the center section,which was firmly fastened to the wing jig.> Result:- perfectly straight and aligned wings.> Easy peasy!> > As far as 'hard shelling' is concerned, I have made two sets ofwings this way, after building a set the 'wet' way.> It is much easier to make an accurate wing by 'hard shelling' withno bumps, hollows etc, and with the glass perfectly straight, with nomicro contamination between plies, and it is much quicker to lay theglass down on a previously prepared, smooth, surface, not to mentionbeing much less messy!> The only filling required on my wings were to fill the weave and theglass spar-cap 'steps', and I would never do it any other way, now.> Hardly a 'moronic' process!> > The glass bonds to the cured micro without any problems, and is justas strong as any other bonding providing that normal 'clean' buildingpractices are observed. (all of the airframe is glued together)> In any case, the weakest link is in the strength of the foam,whichever way you do it.> > Paul Buckley> Cheshire, England.> > Waddelow TriQ-200.....still building.> > > > ----- Original Message ----- > From: Sam Hoskins > To: Q-LIST@... > Sent: Thursday, November 15, 2007 12:26 AM> Subject: Re: [Q-LIST] Re: Initial foam alignment> > > Re your comment: "I am inclined to "build" the exterior BL 100-51) *to> center section (BL 51-0)* on a flat surface - let the micro dry.Then take> the two completed wings and butter up the center (at BL00) and allthe given> jigs "work" per the plans.."> > I did exactly that on the last wing I built and it was sooo mucheasier.> > Sam Hoskins> Murphysboro, IL> > On Nov 14, 2007 6:21 PM, Michael Quinn <mquinn6@...> wrote:> > >> > John, Everything makes sense after you do it... I just have notdone this> > before. I wish there was someone local to Charlotte that is afew steps> > ahead of me so I could work w/ them and learn - then mine wouldbe better by> > one generation of build experience! I think thru the processmany times> > before attacking it so that I can reduce the "damn I did it thehard way..."> > I am certain w/ pracitce/experience it will become easier. Ire-re-reread> > the plans and they talk about the jig - but the female jigs onlywere> > supporting one section of foam or the other (or are theybridging it?!?! - I> > have female jigs of 3/4 plywood (scared b/c of the which hatpotential since> > they are cut square and "should" only make contact with the wingin one> > point (lowest side of the wing). Do you micro and pin thejoints? I look at> > jigs from the picts sent to me from others and they look nothinglike the> > plans. I just am running thru the build process of the main wingand it goes> > like - check everything for fit and alignment - recheck this atleast 100> > times. assemble the center joint less than 1/16 gap (I do nothave the plans> > in front of me - but the purpose is for complete bond and reducethe risk of> > exothermic and melting foam and making a non bonded gap (yes?)). Ok,> > assuming gravity still is working in the downward direction -doesn't it> > make the center section of the main wing "want" to pull apart. Inoticed the> > 5min. epoxy between the foam and female jigs - assume that giveyou enough> > time to work the foam into final resting place after lathing -then it hold> > until the micro cures. Continuing on, the external two foam wingcores> > (already check fitted 100 times) are buttered with micro and putonto the> > assembly that I just completed (5 min. epoxy should hold itright?). Now -> > the female wing jig is on the center section (the plan show iton the> > external foam cores! this would change the angles of dihedraland make> > "curved" wings....), thus I scratch my brain (but not thru thenose)... If> > they are on the exterior part of the wing - I am inclined to"build" the> > exterior BL 100-51) *to center section (BL 51-0)* on a flatsurface - let> > the micro dry. Then take the two completed wings and butter upthe center> > (at BL00) and all the given jigs "work" per the plans....Hardshelling => > slathering and curing, sanding micro prior to starting to glass?I have read> > several success stories about this method - my fear is the lessthan optimum> > bond between the hardened micro and the glass lay-up. And weight(which the> > argument is you will have to use that micro on the outsideotherwise). Since> > one does not peel ply the micro (since it is sanded down totrue) - the last> > sanding would be done with 60 grit to leave connection points ofpure epoxy> > prior to glass. Please be gentile I am a virgin with regards to the> > quickie.... M. *Not certain on BL measurements - just pullingthese numbers> > from what I thought I remember reading...> >> > To: Q-LIST@... <Q-LIST%40yahoogroups.comFrom>:> > johntenhave@... <johntenhave%40yahoo.comDate>: Wed, 14 Nov 2007> > 08:25:38 +0000Subject: [Q-LIST] Re: Initial foam alignment> >> > M,you are attempting to partially fix one problem whilstignoring therest> > of the process. The problem you are trying to fix willbeunlikely to exist> > if you follow a very well worn path.Let me add the followingsuggestions> > and forgive me if some of thesethings seem so trivial as to betoo obvious> > to state.1. The final product accuracy will be dependent uponthe sum of> > theerrors in each of the steps leading to the final product. i.e.> > jig,templates, hot wiring, joining, glassing, filling.2. Getyour jig> > right, and spend as much time on it as is needed toget thedesired level of> > accuracy. Remember that a jig is a devicedesigned to permitordinary levels> > of skill to achieve levels ofaccuracy higher than normallypossible. 3. Get> > your hot wire templates spot on, make them as thin aspossibleand make sure> > that they permit a smooth passage of the the hot wire.errorscome from> > snagging wires, dragging drooping wires, cooling ofthe wires,and hidden> > obstructions. Why thin? remember that you are cutting a taperand if you use> > eachtemplate twice you will cut foam matching faces. Each facewill usethe> > same face/edge of the template. One face/edge will be adjacenttothe foam> > but the other foam block will be spaced out by the thicknessofthe template> > and will cut oversize. To better visualise this, thinkaboutcutting a> > witches hat out of foam in two parts. Imagine a 1"thick templatehalfway up> > the hat. with the hat upright, the top halfwill use the top edgeof the> > template. Cutting the bottom half willstill use the top edge ofthe template> > but the taper will mean thatthe wire meets the top of the foamon an angle> > and will cut over size. 4. Smooth passage of the wire meanssmooth templates> > and smoothoperators. 5. Snagging comes from :a. the nailsholding the> > templates to the foam at an angle whichintersects the wire path- so point> > them inwards and locate them aninch or so from the cutsurface.b. the wire> > hitting blobs of micro joining blocks prior to hot wiring- souse very> > little, and leave the edges free of micro ~ 1/4" or so.You canfill this> > gap later and there is no point in making thejoint any strongerthan the> > parent foam. The foam is a mold, thestructure is the glass. 6.Drooping> > comes from wire lengthening, wire dragging and unevenheating andpoor> > technique.7. When cutting the second half of a wing block putthe core> > back intothe block from which you have just cut it.Somesuggestions : use> > 0.032" stainless steel mig welding wire whichis orders of magnitude> > stronger than lockwire, use a good power supplywhich you cancontrol quickly> > and easily, build a strong light hotwiresaw and heat and tightenthe wire> > till your eyes bleed.. Plucking thewire will tell you when youhave reached> > yield. Practice at different temps and speed until you get dogbone> > freeshapes. This means slow on sharp curves, faster on shallowcurves,tight> > hot wires and smooth accurate number following - at both ends.8.> > Choreograph each cut before you make it and make sure the sawcanreach the> > whole cut, the weights used to hold everything down canbecleared, and the> > saw power supply cable is long enough - remember thatif you snagyou stop,> > if you stop you burn and cut over size - sothe immediate actionif you snag> > is out at right angles to the template.9. store your cores inthe cut out> > portions.10 join the cores in the jig and run a straight edge along> > theleading edge to maximise alignment. Split differences and aimto makeany> > error a hollow rather than a hump.11. When glued remember this -0.020" of> > glass over corrugated ironwill not change the surface into anice rink so> > sand your foam with along sanding block, a long straight edgeand along the> > lines whichjoin the talking lines spanwise. Foam is much mucheasier to sand> > thaneither micro or glass. and get it to within 0.030" or so.Use lightand> > sand intelligently. One stroke of the sanding block will makeadifference.> > Do not hard shell - this is a moronic process. Lets continue the> > conversation when you get to glassing, there arelots of ways tomake that> > simpler and easier as well. Hope this helpsJohn--- In> > Q-LIST@... <Q-LIST%40yahoogroups.com>, "mtyquinn665"> > <mquinn6@> wrote:>> I am trying VERY hard not to reinvent thewheel but I> > am attempting to > build the wing on a jig and see posting wherewashout and> > wing > alignment (of the foam) caused the final product to notbe as perfect> > > as intended. (any sanding to match the other foam indicates an> inacuracy> > in following the template when hot wiring - then one sands to >match and> > you are left with an "original" airfoil)> > My thought is tomake a slot cut> > (90 degrees perpendicular to the > surface) 1/2 inch deep at theWL between> > the foam sections and use a > 1/16" x 1" ( x width of the wingat that point> > minus 1 in or so) strip > of plastic as a key (this concept isfrom years of> > woodworking and what > we call "biskets"). > > To test forlevelness a equal> > length wood skewer could be inserted > (using a small square toinsure> > perpendicular to skin in 2 planes) > until it makes contact w/the plastic> > (prior to glassing)and a level > could be placed on top of theskewers. > >> > Does this make any sense?> > M.>> >> > __________________________________________________________> > Climb to the top of the charts! Play Star Shuffle: the word scramble> > challenge with star power.> >http://club.live.com/star_shuffle.aspx?icid=starshuffle_wlmailtextlink_oct> >> >> > > >> > > >> > -- > Sam Hoskins> www.MistakeProofing.Net> www.MistakeProofing.net/blog/> 618-967-0016 ph.> 312-212-4086 fax> > > > > > > > >----------------------------------------------------------> > > No virus found in this incoming message.> Checked by AVG Free Edition. > Version: 7.5.503 / Virus Database: 269.15.31/1129 - Release Date:13/11/2007 21:22> > > >






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Richard Hole <rickhole@...>
 

I asked the Velocity production people about their wing construction and
hard-shelling. These guys make wings for a living and have done it
hundreds of times. Do they use the wet application or hard-shell?

The answer is that it depends on temperature, humidity, and time of day.
When temperatures are rising, especially with higher humidity, the micro
slurry will out-gas and leave bubbles of delamination, so they may hard
shell instead. Normally they prefer the faster wet application as John
TenHave described.

There is no appreciable difference in final weight, the same amount of
slurry is applied, and, since this is NOT applied to correct surface
irregularities, not much of it is sanded off, just roughen the surface.

Rick


Michael Quinn
 

If they had only 2 or three people able to measure/mix and layup - would they choose the hard? I read other sites and this seems to be one of the arguments (reasons) for homebuilders (vs. production builders) going w/ hardshell.

M.


To: Q-LIST@...: rickhole@...: Fri, 16 Nov 2007 23:46:56 +0000Subject: [Q-LIST] Re: Why hard shelling is a dumb idea




I asked the Velocity production people about their wing construction andhard-shelling. These guys make wings for a living and have done ithundreds of times. Do they use the wet application or hard-shell?The answer is that it depends on temperature, humidity, and time of day.When temperatures are rising, especially with higher humidity, the microslurry will out-gas and leave bubbles of delamination, so they may hardshell instead. Normally they prefer the faster wet application as JohnTenHave described.There is no appreciable difference in final weight, the same amount ofslurry is applied, and, since this is NOT applied to correct surfaceirregularities, not much of it is sanded off, just roughen the surface.Rick






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Peter Harris <peterjfharris@...>
 

Paul,

It is just too easy to have a misunderstanding by email. I know.

John is actually not in any way arrogant (not allowed by Kiwis living in OZ
the survival rate is too low)

He is an expert practicing engineer, a perfectionist and a good teacher.

Cheers

Peter



_____

From: Q-LIST@... [mailto:Q-LIST@...] On Behalf Of
Allan Farr
Sent: Saturday, 17 November 2007 8:30 AM
To: Q-LIST@...
Subject: Re: [Q-LIST] Why hard shelling is a dumb idea



Paul. John T H knows what he is talking about and I (for one) appreciate his
very detailed expert posts.
Allan F

----- Original Message -----
From: Paul Buckley
To: Q-LIST@yahoogroups. <mailto:Q-LIST%40yahoogroups.com> com
Sent: Friday, 16 November 2007 11:43
Subject: Re: [Q-LIST] Why hard shelling is a dumb idea

Hi Mike

I find John Tenhave very irritating with his arrogant and patronising
manner!
I know I shouldn't let it get to me (and I am not the first) and usually I
don't, but this time it did!!
Sorry!
Comments below........
----- Original Message -----
From: Michael Quinn
To: q-list@yahoogroups. <mailto:q-list%40yahoogroups.com> com
Sent: Thursday, November 15, 2007 9:10 PM
Subject: RE: [Q-LIST] Why hard shelling is a dumb idea

Paul,

All this makes sense. I still think the bond between hardshell or micro-wet
layup the weak point is between the micro (whether hard or wet) and not the
rough sanded hard and glass. Yes the chemical bond on the wet lay-up will be
stronger - but the chain is only as strong as the weakest link (whichever
way and the foam). Exactly my point......I can see where the argument is
coming from, but the perceived problem simply does not exist.

The only way I see to make this better would be to take and put negative
"teeth" in the foam with a nail every 1/2" (or so) to provide a better
"bite" for the micro slurry to get into - IF you could be assured of getting
down into the cavities. This of course would add weight. Yes, it would, but
the original foam was orange and had a larger cell size than the blue. This,
it was originally claimed, made for a better 'peel' strength. However,
builders have been using the blue variety for years now, with no adverse
problems. If it worries you, why not make an indentation tool out of a small
cog wheel, and run it along the foam? Quicker than using a nail.

Did you modify the original LS1 templates and EP1212 templates to account
for the thickness of the glass layup? Or did you draw out the spar cap and
sand down the foam where the thicker layers go? Good point about the final
profile! I am curious how many true profiles after either technique are out
there!!! No, and I know of no one who has. I don't even know if the original
templates were drawn to allow for the glass, but I seriously doubt it.
Modifying them would add an inordinate amount of work, and for what? Why do
it when so many Quickies are flying successfully without any thought being
given to it?
The airfoils are tapered so if you want to make a 'final profile' template
it will only fit in one place along the span. What about the rest of the
wing? Are you going to make one for every foot or so? I don't think so, but
that doesn't mean that I think that some sort of profile template, for a
particular spot, wouldn't be a bad idea.
There are several reasons why I think that 'hard shelling' is a better way
to go and not one of the 'reasons' that John came up with has convinced me
otherwise.
I really don't think that he can see the wood for the trees and does not
think in a practical way!
However, I am not saying that everyone should build their wings the 'hard
shell' way, it is a matter of assessment and personal choice.
I, personally, assessed it (from experience) and made my choice. I would,
now, never make wing any other way...I think that the method is far superior
BUT, I do not expect everyone to agree with me and I certainly will not stop
talking to you if you decide to go the 'wet' way!

Kind regards

Paul
M.

To: Q-LIST@yahoogroups. <mailto:Q-LIST%40yahoogroups.comFrom> comFrom:
johntenhave@ <mailto:johntenhave%40yahoo.comDate> yahoo.comDate: Thu, 15 Nov
2007 08:54:41 +0000Subject: [Q-LIST] Why hard shelling is a dumb idea

OK, Paul before I go any further I am going to spell out the reasons why
hardshelling is dumb and my comments are only directed at the method NOTat
those who choose to use it. This is not a personal attack, pleasedo not take
it as such. I am also not saying that you cannot get awing from using the
process but rather that you have done far morework than you you need to do,
will most likely have have a heavierwing and may have a less accurate
product. For reasons I will expandupon in a moment you may well also finish
up with an inferior level offinish.Firstly lets clearly define what we are
trying to achieve:a smooth, straight, accurate, structurally efficient
aerodynamically correct airfoil with the best possible finish in the
shortest possibletime.The final shape is the outside. The outside is the
resultant of (starting at the bottom surface) paint, primer surfacer,
micro/filler,glass, glass foam interface, foam ...center line and then the
sameseries in reverse. All of us only have so much sanding in us. Eventually
the mostdiligent and persistent of us will give up and go fly so let me
submitthat the smart thing to do is to spend that resource wisely.Finishing
occurs at the point in a project when our physical,financial, energy and
enthusiasm resources are at an ebb. Unfortunately, two factors conspire to
get us. The first factor isthat the last thing we do is the first thing that
everyone sees andunfortunately the total quality is often judged by the
finish. Itbehooves us to get the finish to the highest possible standard
(butnot at any cost or weight). What is the acceptable standard? Shortanswer
- luxury car paint finish is a good standard to aim for. The second factor
is that not everyone realises that the top coat isbest regarded as colour
and shine on the substrate. Spraying 30microns of paint on a cheese grater
will not transform it into amirror. So the substrate has to be your very
best work so do it onceand do it right.Finishing is a progressive process.
First flat, then increasinglysmooth. And there is a difference - a pool ball
is smooth but it isnot flat, the billiard table is flat but it is not
smooth. Polishingthe slate under the felt will not make the fabric finish
any smoother.All the issues that Paul as identified as being rectified could
andshould have been rectified by sanding the foam. Foam is much easierto
sand than micro (we will get to glass in a moment). It is also ofuniform
density so it sands evenly and quickly. You are subtractingweight. The
process is fast, easy and you are working below the finalprofile.You are
neither micro cure cycle time dependent nor faced with havingto spread,
smooth, cure fill, sand, fill,each time adding weight,making dust. Break
though the shell whilst sanding and the foam is gone in aheartbeat - more
repairs needed, more weight, more wait. And whatshape do you finish the hard
shell to? If you use the final finishtemplate (and there is is no other
option) by definition when youfinish the construction process, you will be
adding additionalmaterial unevenly on top of what you have tried to make the
correctshape. Result? An inescapably incorrect shape. But that is not
all.All that work and you have achieved a surface finish which
isinappropriate and unnecessary for that stage in the finish. You have a
surface which provides a poorer bond interface between theglass and the foam
than the chemical and mechanical bond providedusing the original approach.
More resin is then required to bond theglass to the micro surface and again
it is only a mechanical bond. The glass bundles have a rigid under surface -
which means that theydo finish up lying under and over to a greater degree
than the wet onwet method combined with peel ply (which should be applied to
everysquare inch of the surface.) The net result is that the glass surfaceis
a raised mesh which is less securely bonded to the micro below andis located
above the the correct profile.And it gets worse. Now you have to sand the
glass surface to dull tobond the micro, so off comes structural strength.
The glass bundlesare not as straight as they could be and then we
deliberately sandthrough them...Lets summarise then.Hard shelling adds
weight, is slower, results in the wrong profile,degrades bond strength
between glass and foam, results in a weakerglass structure - and then you
have to do it all again!! Remember thesanding effort is a finite resource
and you have spent half of italready...Hardshelling makes as much sense as
practice bleeding..Hope that explains the one liner a little more
clearly..John--- In Q-LIST@yahoogroups. <mailto:Q-LIST%40yahoogroups.com>
com, "Paul Buckley" <paulbuckley@...> wrote:>> Me too!> > I actually aligned
the two outer wing cores vertically on my bench,shearweb down, between two
long straight edges which matched the taperof the wings, thus ensuring that
the shearweb was flat and straight,as were all other joined surfaces. I also
pinned the joint with shortwood dowels located on the level lines, but that
isn't reallynecessary as you can simply lightly clamp two straight boards on
eachside of the wing surfaces across the joint (as they are
sittingvertically, on the shearweb), which will ensure that the panels
arealigned accurately.> When cured both wings were then offered up to the
center section,which was firmly fastened to the wing jig.> Result:-
perfectly straight and aligned wings.> Easy peasy!> > As far as 'hard
shelling' is concerned, I have made two sets ofwings this way, after
building a set the 'wet' way.> It is much easier to make an accurate wing by
'hard shelling' withno bumps, hollows etc, and with the glass perfectly
straight, with nomicro contamination between plies, and it is much quicker
to lay theglass down on a previously prepared, smooth, surface, not to
mentionbeing much less messy!> The only filling required on my wings were to
fill the weave and theglass spar-cap 'steps', and I would never do it any
other way, now.> Hardly a 'moronic' process!> > The glass bonds to the cured
micro without any problems, and is justas strong as any other bonding
providing that normal 'clean' buildingpractices are observed. (all of the
airframe is glued together)> In any case, the weakest link is in the
strength of the foam,whichever way you do it.> > Paul Buckley> Cheshire,
England.> > Waddelow TriQ-200.....still building.> > > > ----- Original
Message ----- > From: Sam Hoskins > To: Q-LIST@yahoogroups.
<mailto:Q-LIST%40yahoogroups.com> com > Sent: Thursday, November 15, 2007
12:26 AM> Subject: Re: [Q-LIST] Re: Initial foam alignment> > > Re your
comment: "I am inclined to "build" the exterior BL 100-51) *to> center
section (BL 51-0)* on a flat surface - let the micro dry.Then take> the two
completed wings and butter up the center (at BL00) and allthe given> jigs
"work" per the plans.."> > I did exactly that on the last wing I built and
it was sooo mucheasier.> > Sam Hoskins> Murphysboro, IL> > On Nov 14, 2007
6:21 PM, Michael Quinn <mquinn6@...> wrote:> > >> > John, Everything makes
sense after you do it... I just have notdone this> > before. I wish there
was someone local to Charlotte that is afew steps> > ahead of me so I could
work w/ them and learn - then mine wouldbe better by> > one generation of
build experience! I think thru the processmany times> > before attacking it
so that I can reduce the "damn I did it thehard way..."> > I am certain w/
pracitce/experience it will become easier. Ire-re-reread> > the plans and
they talk about the jig - but the female jigs onlywere> > supporting one
section of foam or the other (or are theybridging it?!?! - I> > have female
jigs of 3/4 plywood (scared b/c of the which hatpotential since> > they are
cut square and "should" only make contact with the wingin one> > point
(lowest side of the wing). Do you micro and pin thejoints? I look at> > jigs
from the picts sent to me from others and they look nothinglike the> >
plans. I just am running thru the build process of the main wingand it goes>
like - check everything for fit and alignment - recheck this atleast 100>
times. assemble the center joint less than 1/16 gap (I do nothave the
plans> > in front of me - but the purpose is for complete bond and reducethe
risk of> > exothermic and melting foam and making a non bonded gap (yes?)).
Ok,> > assuming gravity still is working in the downward direction -doesn't
it> > make the center section of the main wing "want" to pull apart.
Inoticed the> > 5min. epoxy between the foam and female jigs - assume that
giveyou enough> > time to work the foam into final resting place after
lathing -then it hold> > until the micro cures. Continuing on, the external
two foam wingcores> > (already check fitted 100 times) are buttered with
micro and putonto the> > assembly that I just completed (5 min. epoxy should
hold itright?). Now -> > the female wing jig is on the center section (the
plan show iton the> > external foam cores! this would change the angles of
dihedraland make> > "curved" wings....), thus I scratch my brain (but not
thru thenose)... If> > they are on the exterior part of the wing - I am
inclined to"build" the> > exterior BL 100-51) *to center section (BL 51-0)*
on a flatsurface - let> > the micro dry. Then take the two completed wings
and butter upthe center> > (at BL00) and all the given jigs "work" per the
plans....Hardshelling => > slathering and curing, sanding micro prior to
starting to glass?I have read> > several success stories about this method -
my fear is the lessthan optimum> > bond between the hardened micro and the
glass lay-up. And weight(which the> > argument is you will have to use that
micro on the outsideotherwise). Since> > one does not peel ply the micro
(since it is sanded down totrue) - the last> > sanding would be done with 60
grit to leave connection points ofpure epoxy> > prior to glass. Please be
gentile I am a virgin with regards to the> > quickie.... M. *Not certain on
BL measurements - just pullingthese numbers> > from what I thought I
remember reading...> >> > To: Q-LIST@... <Q-LIST%40yahoogroups.comFrom>:> >
johntenhave@... <johntenhave%40yahoo.comDate>: Wed, 14 Nov 2007> > 08:25:38
+0000Subject: [Q-LIST] Re: Initial foam alignment> >> > M,you are attempting
to partially fix one problem whilstignoring therest> > of the process. The
problem you are trying to fix willbeunlikely to exist> > if you follow a
very well worn path.Let me add the followingsuggestions> > and forgive me if
some of thesethings seem so trivial as to betoo obvious> > to state.1. The
final product accuracy will be dependent uponthe sum of> > theerrors in each
of the steps leading to the final product. i.e.> > jig,templates, hot
wiring, joining, glassing, filling.2. Getyour jig> > right, and spend as
much time on it as is needed toget thedesired level of> > accuracy. Remember
that a jig is a devicedesigned to permitordinary levels> > of skill to
achieve levels ofaccuracy higher than normallypossible. 3. Get> > your hot
wire templates spot on, make them as thin aspossibleand make sure> > that
they permit a smooth passage of the the hot wire.errorscome from> > snagging
wires, dragging drooping wires, cooling ofthe wires,and hidden> >
obstructions. Why thin? remember that you are cutting a taperand if you use>
eachtemplate twice you will cut foam matching faces. Each facewill usethe>
same face/edge of the template. One face/edge will be adjacenttothe foam>
but the other foam block will be spaced out by the thicknessofthe
template> > and will cut oversize. To better visualise this,
thinkaboutcutting a> > witches hat out of foam in two parts. Imagine a
1"thick templatehalfway up> > the hat. with the hat upright, the top
halfwill use the top edgeof the> > template. Cutting the bottom half
willstill use the top edge ofthe template> > but the taper will mean thatthe
wire meets the top of the foamon an angle> > and will cut over size. 4.
Smooth passage of the wire meanssmooth templates> > and smoothoperators. 5.
Snagging comes from :a. the nailsholding the> > templates to the foam at an
angle whichintersects the wire path- so point> > them inwards and locate
them aninch or so from the cutsurface.b. the wire> > hitting blobs of micro
joining blocks prior to hot wiring- souse very> > little, and leave the
edges free of micro ~ 1/4" or so.You canfill this> > gap later and there is
no point in making thejoint any strongerthan the> > parent foam. The foam is
a mold, thestructure is the glass. 6.Drooping> > comes from wire
lengthening, wire dragging and unevenheating andpoor> > technique.7. When
cutting the second half of a wing block putthe core> > back intothe block
from which you have just cut it.Somesuggestions : use> > 0.032" stainless
steel mig welding wire whichis orders of magnitude> > stronger than
lockwire, use a good power supplywhich you cancontrol quickly> > and easily,
build a strong light hotwiresaw and heat and tightenthe wire> > till your
eyes bleed.. Plucking thewire will tell you when youhave reached> > yield.
Practice at different temps and speed until you get dogbone> > freeshapes.
This means slow on sharp curves, faster on shallowcurves,tight> > hot wires
and smooth accurate number following - at both ends.8.> > Choreograph each
cut before you make it and make sure the sawcanreach the> > whole cut, the
weights used to hold everything down canbecleared, and the> > saw power
supply cable is long enough - remember thatif you snagyou stop,> > if you
stop you burn and cut over size - sothe immediate actionif you snag> > is
out at right angles to the template.9. store your cores inthe cut out> >
portions.10 join the cores in the jig and run a straight edge along> >
theleading edge to maximise alignment. Split differences and aimto makeany>
error a hollow rather than a hump.11. When glued remember this -0.020" of>
glass over corrugated ironwill not change the surface into anice rink so>
sand your foam with along sanding block, a long straight edgeand along
the> > lines whichjoin the talking lines spanwise. Foam is much mucheasier
to sand> > thaneither micro or glass. and get it to within 0.030" or so.Use
lightand> > sand intelligently. One stroke of the sanding block will
makeadifference.> > Do not hard shell - this is a moronic process. Lets
continue the> > conversation when you get to glassing, there arelots of ways
tomake that> > simpler and easier as well. Hope this helpsJohn--- In> >
Q-LIST@yahoogroups. <mailto:Q-LIST%40yahoogroups.com> com
<Q-LIST%40yahoogroups.com>, "mtyquinn665"> > <mquinn6@> wrote:>> I am trying
VERY hard not to reinvent thewheel but I> > am attempting to > build the
wing on a jig and see posting wherewashout and> > wing > alignment (of the
foam) caused the final product to notbe as perfect> > > as intended. (any
sanding to match the other foam indicates an> inacuracy> > in following the
template when hot wiring - then one sands to >match and> > you are left with
an "original" airfoil)> > My thought is tomake a slot cut> > (90 degrees
perpendicular to the > surface) 1/2 inch deep at theWL between> > the foam
sections and use a > 1/16" x 1" ( x width of the wingat that point> > minus
1 in or so) strip > of plastic as a key (this concept isfrom years of> >
woodworking and what > we call "biskets"). > > To test forlevelness a equal>
length wood skewer could be inserted > (using a small square toinsure> >
perpendicular to skin in 2 planes) > until it makes contact w/the plastic> >
(prior to glassing)and a level > could be placed on top of theskewers. > >>
Does this make any sense?> > M.>> >> >
__________________________________________________________> > Climb to the
top of the charts! Play Star Shuffle: the word scramble> > challenge with
star power.> >http://club.
<http://club.live.com/star_shuffle.aspx?icid=starshuffle_wlmailtextlink_oct>
live.com/star_shuffle.aspx?icid=starshuffle_wlmailtextlink_oct> >> >> >
-- > Sam
Hoskins> www.MistakeProofing.Net> www.MistakeProofing.net/blog/>
618-967-0016 ph.> 312-212-4086 fax> > [Non-text portions of this message
have been removed]> > > > > >
----------------------------------------------------------> > > No virus
found in this incoming message.> Checked by AVG Free Edition. > Version:
7.5.503 / Virus Database: 269.15.31/1129 - Release Date:13/11/2007 21:22> >
__________________________________________________________
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Quickie Builders Association WEB site
http://www.quickieb <http://www.quickiebuilders.org> uilders.org

Yahoo! Groups Links

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Quickie Builders Association WEB site
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Yahoo! Groups Links

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12:56


Bruce Crain
 

I did the hard shelling on my TriQ200 Waddelow 228" wing and canard. It worked fine and is still flying perfectly. It gave me a chance to bond the skins to the vertical mid spar flox dam without getting micro in between the two. But we are talking "apples to oranges" in the build approach.

Bruce Crain
N96BJ




_____________________________________________________________
Make nail fungus a thing of the past by clicking here now!
http://thirdpartyoffers.juno.com/TGL2111/fc/Ioyw6iiepcJ2GMKgOavxNVLBrR3cFhD0WAere5I8gO7yqvsmiqUOdq/


Paul Buckley
 

You are right Peter, email has a way of doing that.
I would like the list to know that my comments were meant to be private, and I have apologised to John for accidentally making them public.
I am sure that he is a fine fellow and accept that he is in no way arrogant, face to face, even tho' he does appear to come across that way.
I also really do consider him to be a clever and intelligent man, as I said.
Perhaps someday I will have the pleasure of meeting you both.

Ciao

Paul.

----- Original Message -----
From: Peter Harris
To: Q-LIST@...
Sent: Saturday, November 17, 2007 12:45 AM
Subject: RE: [Q-LIST] Why hard shelling is a dumb idea


Paul,

It is just too easy to have a misunderstanding by email. I know.

John is actually not in any way arrogant (not allowed by Kiwis living in OZ
the survival rate is too low)

He is an expert practicing engineer, a perfectionist and a good teacher.

Cheers

Peter

_____

From: Q-LIST@... [mailto:Q-LIST@...] On Behalf Of
Allan Farr
Sent: Saturday, 17 November 2007 8:30 AM
To: Q-LIST@...
Subject: Re: [Q-LIST] Why hard shelling is a dumb idea

Paul. John T H knows what he is talking about and I (for one) appreciate his
very detailed expert posts.
Allan F
----- Original Message -----
From: Paul Buckley
To: Q-LIST@yahoogroups. <mailto:Q-LIST%40yahoogroups.com> com
Sent: Friday, 16 November 2007 11:43
Subject: Re: [Q-LIST] Why hard shelling is a dumb idea

Hi Mike

I find John Tenhave very irritating with his arrogant and patronising
manner!
I know I shouldn't let it get to me (and I am not the first) and usually I
don't, but this time it did!!
Sorry!
Comments below........
----- Original Message -----
From: Michael Quinn
To: q-list@yahoogroups. <mailto:q-list%40yahoogroups.com> com
Sent: Thursday, November 15, 2007 9:10 PM
Subject: RE: [Q-LIST] Why hard shelling is a dumb idea

Paul,

All this makes sense. I still think the bond between hardshell or micro-wet
layup the weak point is between the micro (whether hard or wet) and not the
rough sanded hard and glass. Yes the chemical bond on the wet lay-up will be
stronger - but the chain is only as strong as the weakest link (whichever
way and the foam). Exactly my point......I can see where the argument is
coming from, but the perceived problem simply does not exist.

The only way I see to make this better would be to take and put negative
"teeth" in the foam with a nail every 1/2" (or so) to provide a better
"bite" for the micro slurry to get into - IF you could be assured of getting
down into the cavities. This of course would add weight. Yes, it would, but
the original foam was orange and had a larger cell size than the blue. This,
it was originally claimed, made for a better 'peel' strength. However,
builders have been using the blue variety for years now, with no adverse
problems. If it worries you, why not make an indentation tool out of a small
cog wheel, and run it along the foam? Quicker than using a nail.

Did you modify the original LS1 templates and EP1212 templates to account
for the thickness of the glass layup? Or did you draw out the spar cap and
sand down the foam where the thicker layers go? Good point about the final
profile! I am curious how many true profiles after either technique are out
there!!! No, and I know of no one who has. I don't even know if the original
templates were drawn to allow for the glass, but I seriously doubt it.
Modifying them would add an inordinate amount of work, and for what? Why do
it when so many Quickies are flying successfully without any thought being
given to it?
The airfoils are tapered so if you want to make a 'final profile' template
it will only fit in one place along the span. What about the rest of the
wing? Are you going to make one for every foot or so? I don't think so, but
that doesn't mean that I think that some sort of profile template, for a
particular spot, wouldn't be a bad idea.
There are several reasons why I think that 'hard shelling' is a better way
to go and not one of the 'reasons' that John came up with has convinced me
otherwise.
I really don't think that he can see the wood for the trees and does not
think in a practical way!
However, I am not saying that everyone should build their wings the 'hard
shell' way, it is a matter of assessment and personal choice.
I, personally, assessed it (from experience) and made my choice. I would,
now, never make wing any other way...I think that the method is far superior
BUT, I do not expect everyone to agree with me and I certainly will not stop
talking to you if you decide to go the 'wet' way!

Kind regards

Paul
M.

To: Q-LIST@yahoogroups. <mailto:Q-LIST%40yahoogroups.comFrom> comFrom:
johntenhave@ <mailto:johntenhave%40yahoo.comDate> yahoo.comDate: Thu, 15 Nov
2007 08:54:41 +0000Subject: [Q-LIST] Why hard shelling is a dumb idea

OK, Paul before I go any further I am going to spell out the reasons why
hardshelling is dumb and my comments are only directed at the method NOTat
those who choose to use it. This is not a personal attack, pleasedo not take
it as such. I am also not saying that you cannot get awing from using the
process but rather that you have done far morework than you you need to do,
will most likely have have a heavierwing and may have a less accurate
product. For reasons I will expandupon in a moment you may well also finish
up with an inferior level offinish.Firstly lets clearly define what we are
trying to achieve:a smooth, straight, accurate, structurally efficient
aerodynamically correct airfoil with the best possible finish in the
shortest possibletime.The final shape is the outside. The outside is the
resultant of (starting at the bottom surface) paint, primer surfacer,
micro/filler,glass, glass foam interface, foam ...center line and then the
sameseries in reverse. All of us only have so much sanding in us. Eventually
the mostdiligent and persistent of us will give up and go fly so let me
submitthat the smart thing to do is to spend that resource wisely.Finishing
occurs at the point in a project when our physical,financial, energy and
enthusiasm resources are at an ebb. Unfortunately, two factors conspire to
get us. The first factor isthat the last thing we do is the first thing that
everyone sees andunfortunately the total quality is often judged by the
finish. Itbehooves us to get the finish to the highest possible standard
(butnot at any cost or weight). What is the acceptable standard? Shortanswer
- luxury car paint finish is a good standard to aim for. The second factor
is that not everyone realises that the top coat isbest regarded as colour
and shine on the substrate. Spraying 30microns of paint on a cheese grater
will not transform it into amirror. So the substrate has to be your very
best work so do it onceand do it right.Finishing is a progressive process.
First flat, then increasinglysmooth. And there is a difference - a pool ball
is smooth but it isnot flat, the billiard table is flat but it is not
smooth. Polishingthe slate under the felt will not make the fabric finish
any smoother.All the issues that Paul as identified as being rectified could
andshould have been rectified by sanding the foam. Foam is much easierto
sand than micro (we will get to glass in a moment). It is also ofuniform
density so it sands evenly and quickly. You are subtractingweight. The
process is fast, easy and you are working below the finalprofile.You are
neither micro cure cycle time dependent nor faced with havingto spread,
smooth, cure fill, sand, fill,each time adding weight,making dust. Break
though the shell whilst sanding and the foam is gone in aheartbeat - more
repairs needed, more weight, more wait. And whatshape do you finish the hard
shell to? If you use the final finishtemplate (and there is is no other
option) by definition when youfinish the construction process, you will be
adding additionalmaterial unevenly on top of what you have tried to make the
correctshape. Result? An inescapably incorrect shape. But that is not
all.All that work and you have achieved a surface finish which
isinappropriate and unnecessary for that stage in the finish. You have a
surface which provides a poorer bond interface between theglass and the foam
than the chemical and mechanical bond providedusing the original approach.
More resin is then required to bond theglass to the micro surface and again
it is only a mechanical bond. The glass bundles have a rigid under surface -
which means that theydo finish up lying under and over to a greater degree
than the wet onwet method combined with peel ply (which should be applied to
everysquare inch of the surface.) The net result is that the glass surfaceis
a raised mesh which is less securely bonded to the micro below andis located
above the the correct profile.And it gets worse. Now you have to sand the
glass surface to dull tobond the micro, so off comes structural strength.
The glass bundlesare not as straight as they could be and then we
deliberately sandthrough them...Lets summarise then.Hard shelling adds
weight, is slower, results in the wrong profile,degrades bond strength
between glass and foam, results in a weakerglass structure - and then you
have to do it all again!! Remember thesanding effort is a finite resource
and you have spent half of italready...Hardshelling makes as much sense as
practice bleeding..Hope that explains the one liner a little more
clearly..John--- In Q-LIST@yahoogroups. <mailto:Q-LIST%40yahoogroups.com>
com, "Paul Buckley" <paulbuckley@...> wrote:>> Me too!> > I actually aligned
the two outer wing cores vertically on my bench,shearweb down, between two
long straight edges which matched the taperof the wings, thus ensuring that
the shearweb was flat and straight,as were all other joined surfaces. I also
pinned the joint with shortwood dowels located on the level lines, but that
isn't reallynecessary as you can simply lightly clamp two straight boards on
eachside of the wing surfaces across the joint (as they are
sittingvertically, on the shearweb), which will ensure that the panels
arealigned accurately.> When cured both wings were then offered up to the
center section,which was firmly fastened to the wing jig.> Result:-
perfectly straight and aligned wings.> Easy peasy!> > As far as 'hard
shelling' is concerned, I have made two sets ofwings this way, after
building a set the 'wet' way.> It is much easier to make an accurate wing by
'hard shelling' withno bumps, hollows etc, and with the glass perfectly
straight, with nomicro contamination between plies, and it is much quicker
to lay theglass down on a previously prepared, smooth, surface, not to
mentionbeing much less messy!> The only filling required on my wings were to
fill the weave and theglass spar-cap 'steps', and I would never do it any
other way, now.> Hardly a 'moronic' process!> > The glass bonds to the cured
micro without any problems, and is justas strong as any other bonding
providing that normal 'clean' buildingpractices are observed. (all of the
airframe is glued together)> In any case, the weakest link is in the
strength of the foam,whichever way you do it.> > Paul Buckley> Cheshire,
England.> > Waddelow TriQ-200.....still building.> > > > ----- Original
Message ----- > From: Sam Hoskins > To: Q-LIST@yahoogroups.
<mailto:Q-LIST%40yahoogroups.com> com > Sent: Thursday, November 15, 2007
12:26 AM> Subject: Re: [Q-LIST] Re: Initial foam alignment> > > Re your
comment: "I am inclined to "build" the exterior BL 100-51) *to> center
section (BL 51-0)* on a flat surface - let the micro dry.Then take> the two
completed wings and butter up the center (at BL00) and allthe given> jigs
"work" per the plans.."> > I did exactly that on the last wing I built and
it was sooo mucheasier.> > Sam Hoskins> Murphysboro, IL> > On Nov 14, 2007
6:21 PM, Michael Quinn <mquinn6@...> wrote:> > >> > John, Everything makes
sense after you do it... I just have notdone this> > before. I wish there
was someone local to Charlotte that is afew steps> > ahead of me so I could
work w/ them and learn - then mine wouldbe better by> > one generation of
build experience! I think thru the processmany times> > before attacking it
so that I can reduce the "damn I did it thehard way..."> > I am certain w/
pracitce/experience it will become easier. Ire-re-reread> > the plans and
they talk about the jig - but the female jigs onlywere> > supporting one
section of foam or the other (or are theybridging it?!?! - I> > have female
jigs of 3/4 plywood (scared b/c of the which hatpotential since> > they are
cut square and "should" only make contact with the wingin one> > point
(lowest side of the wing). Do you micro and pin thejoints? I look at> > jigs
from the picts sent to me from others and they look nothinglike the> >
plans. I just am running thru the build process of the main wingand it goes>
> like - check everything for fit and alignment - recheck this atleast 100>
> times. assemble the center joint less than 1/16 gap (I do nothave the
plans> > in front of me - but the purpose is for complete bond and reducethe
risk of> > exothermic and melting foam and making a non bonded gap (yes?)).
Ok,> > assuming gravity still is working in the downward direction -doesn't
it> > make the center section of the main wing "want" to pull apart.
Inoticed the> > 5min. epoxy between the foam and female jigs - assume that
giveyou enough> > time to work the foam into final resting place after
lathing -then it hold> > until the micro cures. Continuing on, the external
two foam wingcores> > (already check fitted 100 times) are buttered with
micro and putonto the> > assembly that I just completed (5 min. epoxy should
hold itright?). Now -> > the female wing jig is on the center section (the
plan show iton the> > external foam cores! this would change the angles of
dihedraland make> > "curved" wings....), thus I scratch my brain (but not
thru thenose)... If> > they are on the exterior part of the wing - I am
inclined to"build" the> > exterior BL 100-51) *to center section (BL 51-0)*
on a flatsurface - let> > the micro dry. Then take the two completed wings
and butter upthe center> > (at BL00) and all the given jigs "work" per the
plans....Hardshelling => > slathering and curing, sanding micro prior to
starting to glass?I have read> > several success stories about this method -
my fear is the lessthan optimum> > bond between the hardened micro and the
glass lay-up. And weight(which the> > argument is you will have to use that
micro on the outsideotherwise). Since> > one does not peel ply the micro
(since it is sanded down totrue) - the last> > sanding would be done with 60
grit to leave connection points ofpure epoxy> > prior to glass. Please be
gentile I am a virgin with regards to the> > quickie.... M. *Not certain on
BL measurements - just pullingthese numbers> > from what I thought I
remember reading...> >> > To: Q-LIST@... <Q-LIST%40yahoogroups.comFrom>:> >
johntenhave@... <johntenhave%40yahoo.comDate>: Wed, 14 Nov 2007> > 08:25:38
+0000Subject: [Q-LIST] Re: Initial foam alignment> >> > M,you are attempting
to partially fix one problem whilstignoring therest> > of the process. The
problem you are trying to fix willbeunlikely to exist> > if you follow a
very well worn path.Let me add the followingsuggestions> > and forgive me if
some of thesethings seem so trivial as to betoo obvious> > to state.1. The
final product accuracy will be dependent uponthe sum of> > theerrors in each
of the steps leading to the final product. i.e.> > jig,templates, hot
wiring, joining, glassing, filling.2. Getyour jig> > right, and spend as
much time on it as is needed toget thedesired level of> > accuracy. Remember
that a jig is a devicedesigned to permitordinary levels> > of skill to
achieve levels ofaccuracy higher than normallypossible. 3. Get> > your hot
wire templates spot on, make them as thin aspossibleand make sure> > that
they permit a smooth passage of the the hot wire.errorscome from> > snagging
wires, dragging drooping wires, cooling ofthe wires,and hidden> >
obstructions. Why thin? remember that you are cutting a taperand if you use>
> eachtemplate twice you will cut foam matching faces. Each facewill usethe>
> same face/edge of the template. One face/edge will be adjacenttothe foam>
> but the other foam block will be spaced out by the thicknessofthe
template> > and will cut oversize. To better visualise this,
thinkaboutcutting a> > witches hat out of foam in two parts. Imagine a
1"thick templatehalfway up> > the hat. with the hat upright, the top
halfwill use the top edgeof the> > template. Cutting the bottom half
willstill use the top edge ofthe template> > but the taper will mean thatthe
wire meets the top of the foamon an angle> > and will cut over size. 4.
Smooth passage of the wire meanssmooth templates> > and smoothoperators. 5.
Snagging comes from :a. the nailsholding the> > templates to the foam at an
angle whichintersects the wire path- so point> > them inwards and locate
them aninch or so from the cutsurface.b. the wire> > hitting blobs of micro
joining blocks prior to hot wiring- souse very> > little, and leave the
edges free of micro ~ 1/4" or so.You canfill this> > gap later and there is
no point in making thejoint any strongerthan the> > parent foam. The foam is
a mold, thestructure is the glass. 6.Drooping> > comes from wire
lengthening, wire dragging and unevenheating andpoor> > technique.7. When
cutting the second half of a wing block putthe core> > back intothe block
from which you have just cut it.Somesuggestions : use> > 0.032" stainless
steel mig welding wire whichis orders of magnitude> > stronger than
lockwire, use a good power supplywhich you cancontrol quickly> > and easily,
build a strong light hotwiresaw and heat and tightenthe wire> > till your
eyes bleed.. Plucking thewire will tell you when youhave reached> > yield.
Practice at different temps and speed until you get dogbone> > freeshapes.
This means slow on sharp curves, faster on shallowcurves,tight> > hot wires
and smooth accurate number following - at both ends.8.> > Choreograph each
cut before you make it and make sure the sawcanreach the> > whole cut, the
weights used to hold everything down canbecleared, and the> > saw power
supply cable is long enough - remember thatif you snagyou stop,> > if you
stop you burn and cut over size - sothe immediate actionif you snag> > is
out at right angles to the template.9. store your cores inthe cut out> >
portions.10 join the cores in the jig and run a straight edge along> >
theleading edge to maximise alignment. Split differences and aimto makeany>
> error a hollow rather than a hump.11. When glued remember this -0.020" of>
> glass over corrugated ironwill not change the surface into anice rink so>
> sand your foam with along sanding block, a long straight edgeand along
the> > lines whichjoin the talking lines spanwise. Foam is much mucheasier
to sand> > thaneither micro or glass. and get it to within 0.030" or so.Use
lightand> > sand intelligently. One stroke of the sanding block will
makeadifference.> > Do not hard shell - this is a moronic process. Lets
continue the> > conversation when you get to glassing, there arelots of ways
tomake that> > simpler and easier as well. Hope this helpsJohn--- In> >
Q-LIST@yahoogroups. <mailto:Q-LIST%40yahoogroups.com> com
<Q-LIST%40yahoogroups.com>, "mtyquinn665"> > <mquinn6@> wrote:>> I am trying
VERY hard not to reinvent thewheel but I> > am attempting to > build the
wing on a jig and see posting wherewashout and> > wing > alignment (of the
foam) caused the final product to notbe as perfect> > > as intended. (any
sanding to match the other foam indicates an> inacuracy> > in following the
template when hot wiring - then one sands to >match and> > you are left with
an "original" airfoil)> > My thought is tomake a slot cut> > (90 degrees
perpendicular to the > surface) 1/2 inch deep at theWL between> > the foam
sections and use a > 1/16" x 1" ( x width of the wingat that point> > minus
1 in or so) strip > of plastic as a key (this concept isfrom years of> >
woodworking and what > we call "biskets"). > > To test forlevelness a equal>
> length wood skewer could be inserted > (using a small square toinsure> >
perpendicular to skin in 2 planes) > until it makes contact w/the plastic> >
(prior to glassing)and a level > could be placed on top of theskewers. > >>
> Does this make any sense?> > M.>> >> >
__________________________________________________________> > Climb to the
top of the charts! Play Star Shuffle: the word scramble> > challenge with
star power.> >http://club.
<http://club.live.com/star_shuffle.aspx?icid=starshuffle_wlmailtextlink_oct>
live.com/star_shuffle.aspx?icid=starshuffle_wlmailtextlink_oct> >> >> >
> >> > > >> > -- > Sam
Hoskins> www.MistakeProofing.Net> www.MistakeProofing.net/blog/>
618-967-0016 ph.> 312-212-4086 fax> > [Non-text portions of this message
have been removed]> > > > > >
>----------------------------------------------------------> > > No virus
found in this incoming message.> Checked by AVG Free Edition. > Version:
7.5.503 / Virus Database: 269.15.31/1129 - Release Date:13/11/2007 21:22> >
> >

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Yahoo! Groups Links

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Dave Dugas
 

Sorry John.....couldn't find them. Dave D

johntenhave <johntenhave@...> wrote: Sure,

check the presentation I posted this morning in the files section.

John

--- In Q-LIST@..., Dave Dugas <davedq2@...> wrote:

John,

Could you post some pictures of your Q? Dave D.

johntenhave <johntenhave@...> wrote:
Paul,

no offence taken, and there is nothing like a healthy, reasoned debate.

Rather than clutter the bandwidth, let your comments stand. Let me
comment briefly on incorrect assumptions and may I direct you and
anyone else how is interested to the composite finishing presentation
I have posted. I was asked to explain to the SAAA how the finish on VH
XMX was achieved, so I did.

A Long Ez has 195 sq ft of wetted area. All of it has to be finished
from foam to paint. A Q2XX is a much smaller, simpler area subset.

I have seen the hardshelling method and you are right - I have not
tried it. Its shortcomings were apparent by inspection, my teachers
(mentioned in the presentation) were masters of the faster method and
that is how I decided which was best.

Yes I am advocating peel plying every square inch of the external and
internal glass work. I will explain my reasoning why in another
posting- if it is not apparent from the presentation.

Regards

John

P.S. Re practical experience? I built and surface finished the Long
Ez used as the example in the presentation - single handed.

As one wry Vari Eze builder once noted : "more like moderately
f**king difficult!"

--- In Q-LIST@..., "Paul Buckley" <paulbuckley@> wrote:

John

Without malice, I disagree with almost everything that you have
said, except maybe the dust!

It is quite obvious that you have never tried or seen this method,
which is well documented.

I reiterate that my wings are as perfect as they could possibly be,
with virtually no micro filler, and that they only require a primer
surfacer to finish.

So the substrate has to be your very best work so do it once
and do it right.<<<<

Exactly!

you have done far more
work than you need to do, will most likely have a heavier
wing and may have a less accurate product <<<<<

Why more work? By all accounts, most builders spend an inordinate
amount of time sanding-filling, sanding-filling, creating copious
amounts of dust in the process.

Why heavier? Using the hard shell method, most of the micro is
sanded away and is only there to provide a straight, hard surface on
which to lay the glass, the resultant cured surface of which is nigh
on perfect.

Why less accurate? You talk about sanding the bare, foam cores.
Surely, doing that destroys any accuracy that you have tried to
achieve by making accurate 'thin' templates!
(and talking about your reasons for using a thin template is rather
like saying that if your pitot head is on the port wing tip, turning
left will give you an ASI reading that is lower than a right turn.
No doubt it will, but it is both academic and unreadable)

You talk about 'only a mechanical bond' between the glass and the
hard shelled surface. Isn't virtually all of the airframe built
relying on mechanical bonds? Have you ever tried to separate two
mechanically bonded surfaces?
The 'mechanical' bond is every bit as strong as any other bond on
the airframe, which I believe holds together pretty well, provided,
like everything else, it is done using the correct techniques.
In any case, the weakest link in the 'skin to foam' bonding is the
foam itself, and I have built test pieces (documented some time ago)
using both methods of construction, and there was no discernable
difference
in the bonding strengths.

Break though the shell whilst sanding and the foam is gone in a
heartbeat - more repairs needed, more weight, more wait<<<<

Rubbish! Are you going to use a belt sander??
When sanding the shell, using a spline, you can clearly see when the
micro is becoming thin, and that is when you stop.
And as the foam cores have been accurately cut and jigged in the
first place, there will be no high spots to break through!
But even if you do break through, it is neither catastrophic or a
problem.

And what shape do you finish the hard shell to? If you use the
final finish
template (and there is is no other option) by definition when you
finish the construction process, you will be adding additional
material unevenly on top of what you have tried to make the correct
shape. Result? An inescapably incorrect shape. <<<<<<<

Really John? I must have missed something. In my 24 years of being
on the 'Quickie' scene, I have never yet seen a 'final finish' template.
Have you? Has anyone?
The hard shell is finished to the same shape as the underlying foam
cores.
Well, to 25thou. anyway! Hopefully, that is good enough!

And it gets worse. Now you have to sand the glass surface
to dull to
bond the micro, so off comes structural strength. The glass bundles
are not as straight as they could be and then we deliberately sand
through them...<<<<<<<<<<

Tell me John, do you not have to sand the glass wing surface in
order to bond the micro filler when using the 'conventional' technique??
Surely you are not advocating the use of peel ply over the whole
wing area? It is a well know fact that doing so is a no-no because it
adds a lot of weight..........
And, using the hard shell method, it is easy to get the glass fibres
dead straight......and I mean, dead straight!

There is no doubt that you are a clever and intelligent man, John,
but I think that you are neither practical or experienced in the
building of glass fibre aeroplanes.
You suffer from what a lot of engineers suffer from, the addiction
to minutia.
You are not building a Swiss watch.........I pay avid attention to
detail and am a perfectionist, but you take your arguments beyond
sensible reason and practicality.

I could go on (and on and on) but I haven't the time or the
patience.......if anyone would like to discuss the pros and cons I am
available off list...... with lots of photos!

Paul Buckley
Cheshire
England

TriQ-200
Still building............





----- Original Message -----
From: johntenhave
To: Q-LIST@...
Sent: Thursday, November 15, 2007 8:54 AM
Subject: [Q-LIST] Why hard shelling is a dumb idea


OK, Paul

before I go any further I am going to spell out the reasons why hard
shelling is dumb and my comments are only directed at the method NOT
at those who choose to use it. This is not a personal attack, please
do not take it as such. I am also not saying that you cannot get a
wing from using the process but rather that you have done far more
work than you you need to do, will most likely have have a heavier
wing and may have a less accurate product. For reasons I will expand
upon in a moment you may well also finish up with an inferior level of
finish.

Firstly lets clearly define what we are trying to achieve:

a smooth, straight, accurate, structurally efficient aerodynamically
correct airfoil with the best possible finish in the shortest possible
time.

The final shape is the outside. The outside is the resultant of (
starting at the bottom surface) paint, primer surfacer, micro/filler
,glass, glass foam interface, foam ...center line and then the same
series in reverse.

All of us only have so much sanding in us. Eventually the most
diligent and persistent of us will give up and go fly so let me submit
that the smart thing to do is to spend that resource wisely.

Finishing occurs at the point in a project when our physical,
financial, energy and enthusiasm resources are at an ebb.
Unfortunately, two factors conspire to get us. The first factor is
that the last thing we do is the first thing that everyone sees and
unfortunately the total quality is often judged by the finish. It
behooves us to get the finish to the highest possible standard (but
not at any cost or weight). What is the acceptable standard? Short
answer - luxury car paint finish is a good standard to aim for.

The second factor is that not everyone realises that the top coat is
best regarded as colour and shine on the substrate. Spraying 30
microns of paint on a cheese grater will not transform it into a
mirror. So the substrate has to be your very best work so do it once
and do it right.

Finishing is a progressive process. First flat, then increasingly
smooth. And there is a difference - a pool ball is smooth but it is
not flat, the billiard table is flat but it is not smooth. Polishing
the slate under the felt will not make the fabric finish any smoother.

All the issues that Paul as identified as being rectified could and
should have been rectified by sanding the foam. Foam is much easier
to sand than micro (we will get to glass in a moment). It is also of
uniform density so it sands evenly and quickly. You are subtracting
weight. The process is fast, easy and you are working below the final
profile.

You are neither micro cure cycle time dependent nor faced with having
to spread, smooth, cure fill, sand, fill,each time adding weight,
making dust.

Break though the shell whilst sanding and the foam is gone in a
heartbeat - more repairs needed, more weight, more wait. And what
shape do you finish the hard shell to? If you use the final finish
template (and there is is no other option) by definition when you
finish the construction process, you will be adding additional
material unevenly on top of what you have tried to make the correct
shape. Result? An inescapably incorrect shape.

But that is not all.

All that work and you have achieved a surface finish which is
inappropriate and unnecessary for that stage in the finish.

You have a surface which provides a poorer bond interface between the
glass and the foam than the chemical and mechanical bond provided
using the original approach. More resin is then required to bond the
glass to the micro surface and again it is only a mechanical bond.

The glass bundles have a rigid under surface - which means that they
do finish up lying under and over to a greater degree than the wet on
wet method combined with peel ply (which should be applied to every
square inch of the surface.) The net result is that the glass surface
is a raised mesh which is less securely bonded to the micro below and
is located above the the correct profile.

And it gets worse. Now you have to sand the glass surface to dull to
bond the micro, so off comes structural strength. The glass bundles
are not as straight as they could be and then we deliberately sand
through them...

Lets summarise then.

Hard shelling adds weight, is slower, results in the wrong profile,
degrades bond strength between glass and foam, results in a weaker
glass structure - and then you have to do it all again!! Remember the
sanding effort is a finite resource and you have spent half of it
already...

Hardshelling makes as much sense as practice bleeding..

Hope that explains the one liner a little more clearly..

John


--- In Q-LIST@..., "Paul Buckley" <paulbuckley@> wrote:

Me too!

I actually aligned the two outer wing cores vertically on my bench,
shearweb down, between two long straight edges which matched the taper
of the wings, thus ensuring that the shearweb was flat and straight,
as were all other joined surfaces. I also pinned the joint with short
wood dowels located on the level lines, but that isn't really
necessary as you can simply lightly clamp two straight boards on each
side of the wing surfaces across the joint (as they are sitting
vertically, on the shearweb), which will ensure that the panels are
aligned accurately.
When cured both wings were then offered up to the center section,
which was firmly fastened to the wing jig.
Result:- perfectly straight and aligned wings.
Easy peasy!

As far as 'hard shelling' is concerned, I have made two sets of
wings this way, after building a set the 'wet' way.
It is much easier to make an accurate wing by 'hard shelling' with
no bumps, hollows etc, and with the glass perfectly straight, with no
micro contamination between plies, and it is much quicker to lay the
glass down on a previously prepared, smooth, surface, not to mention
being much less messy!
The only filling required on my wings were to fill the weave and the
glass spar-cap 'steps', and I would never do it any other way, now.
Hardly a 'moronic' process!

The glass bonds to the cured micro without any problems, and is just
as strong as any other bonding providing that normal 'clean' building
practices are observed. (all of the airframe is glued together)
In any case, the weakest link is in the strength of the foam,
whichever way you do it.

Paul Buckley
Cheshire, England.

Waddelow TriQ-200.....still building.



----- Original Message -----
From: Sam Hoskins
To: Q-LIST@...
Sent: Thursday, November 15, 2007 12:26 AM
Subject: Re: [Q-LIST] Re: Initial foam alignment


Re your comment: "I am inclined to "build" the exterior BL
100-51) *to
center section (BL 51-0)* on a flat surface - let the micro dry.
Then take
the two completed wings and butter up the center (at BL00) and all
the given
jigs "work" per the plans.."

I did exactly that on the last wing I built and it was sooo much
easier.

Sam Hoskins
Murphysboro, IL

On Nov 14, 2007 6:21 PM, Michael Quinn <mquinn6@> wrote:


John, Everything makes sense after you do it... I just have not
done this
before. I wish there was someone local to Charlotte that is a
few steps
ahead of me so I could work w/ them and learn - then mine would
be better by
one generation of build experience! I think thru the process
many times
before attacking it so that I can reduce the "damn I did it the
hard way..."
I am certain w/ pracitce/experience it will become easier. I
re-re-reread
the plans and they talk about the jig - but the female jigs only
were
supporting one section of foam or the other (or are they
bridging it?!?! - I
have female jigs of 3/4 plywood (scared b/c of the which hat
potential since
they are cut square and "should" only make contact with the wing
in one
point (lowest side of the wing). Do you micro and pin the
joints? I look at
jigs from the picts sent to me from others and they look nothing
like the
plans. I just am running thru the build process of the main wing
and it goes
like - check everything for fit and alignment - recheck this at
least 100
times. assemble the center joint less than 1/16 gap (I do not
have the plans
in front of me - but the purpose is for complete bond and reduce
the risk of
exothermic and melting foam and making a non bonded gap
(yes?)). Ok,
assuming gravity still is working in the downward direction -
doesn't it
make the center section of the main wing "want" to pull apart. I
noticed the
5min. epoxy between the foam and female jigs - assume that give
you enough
time to work the foam into final resting place after lathing -
then it hold
until the micro cures. Continuing on, the external two foam wing
cores
(already check fitted 100 times) are buttered with micro and put
onto the
assembly that I just completed (5 min. epoxy should hold it
right?). Now -
the female wing jig is on the center section (the plan show it
on the
external foam cores! this would change the angles of dihedral
and make
"curved" wings....), thus I scratch my brain (but not thru the
nose)... If
they are on the exterior part of the wing - I am inclined to
"build" the
exterior BL 100-51) *to center section (BL 51-0)* on a flat
surface - let
the micro dry. Then take the two completed wings and butter up
the center
(at BL00) and all the given jigs "work" per the plans....
Hardshelling =
slathering and curing, sanding micro prior to starting to glass?
I have read
several success stories about this method - my fear is the less
than optimum
bond between the hardened micro and the glass lay-up. And weight
(which the
argument is you will have to use that micro on the outside
otherwise). Since
one does not peel ply the micro (since it is sanded down to
true) - the last
sanding would be done with 60 grit to leave connection points of
pure epoxy
prior to glass. Please be gentile I am a virgin with regards
to the
quickie.... M. *Not certain on BL measurements - just pulling
these numbers
from what I thought I remember reading...

To: Q-LIST@ <Q-LIST%40yahoogroups.comFrom>:
johntenhave@ <johntenhave%40yahoo.comDate>: Wed, 14 Nov 2007
08:25:38 +0000Subject: [Q-LIST] Re: Initial foam alignment

M,you are attempting to partially fix one problem whilst
ignoring therest
of the process. The problem you are trying to fix will
beunlikely to exist
if you follow a very well worn path.Let me add the following
suggestions
and forgive me if some of thesethings seem so trivial as to be
too obvious
to state.1. The final product accuracy will be dependent upon
the sum of
theerrors in each of the steps leading to the final product. i.e.
jig,templates, hot wiring, joining, glassing, filling.2. Get
your jig
right, and spend as much time on it as is needed toget the
desired level of
accuracy. Remember that a jig is a devicedesigned to permit
ordinary levels
of skill to achieve levels ofaccuracy higher than normally
possible. 3. Get
your hot wire templates spot on, make them as thin as
possibleand make sure
that they permit a smooth passage of the the hot wire.errors
come from
snagging wires, dragging drooping wires, cooling ofthe wires,
and hidden
obstructions. Why thin? remember that you are cutting a taper
and if you use
eachtemplate twice you will cut foam matching faces. Each face
will usethe
same face/edge of the template. One face/edge will be adjacent
tothe foam
but the other foam block will be spaced out by the thicknessof
the template
and will cut oversize. To better visualise this, thinkabout
cutting a
witches hat out of foam in two parts. Imagine a 1"thick template
halfway up
the hat. with the hat upright, the top halfwill use the top edge
of the
template. Cutting the bottom half willstill use the top edge of
the template
but the taper will mean thatthe wire meets the top of the foam
on an angle
and will cut over size. 4. Smooth passage of the wire means
smooth templates
and smoothoperators. 5. Snagging comes from :a. the nails
holding the
templates to the foam at an angle whichintersects the wire path
- so point
them inwards and locate them aninch or so from the cut
surface.b. the wire
hitting blobs of micro joining blocks prior to hot wiring- so
use very
little, and leave the edges free of micro ~ 1/4" or so.You can
fill this
gap later and there is no point in making thejoint any stronger
than the
parent foam. The foam is a mold, thestructure is the glass. 6.
Drooping
comes from wire lengthening, wire dragging and unevenheating and
poor
technique.7. When cutting the second half of a wing block put
the core
back intothe block from which you have just cut it.Some
suggestions : use
0.032" stainless steel mig welding wire whichis orders of
magnitude
stronger than lockwire, use a good power supplywhich you can
control quickly
and easily, build a strong light hotwiresaw and heat and tighten
the wire
till your eyes bleed.. Plucking thewire will tell you when you
have reached
yield. Practice at different temps and speed until you get dogbone
freeshapes. This means slow on sharp curves, faster on shallow
curves,tight
hot wires and smooth accurate number following - at both ends.8.
Choreograph each cut before you make it and make sure the saw
canreach the
whole cut, the weights used to hold everything down can
becleared, and the
saw power supply cable is long enough - remember thatif you snag
you stop,
if you stop you burn and cut over size - sothe immediate action
if you snag
is out at right angles to the template.9. store your cores in
the cut out
portions.10 join the cores in the jig and run a straight edge
along
theleading edge to maximise alignment. Split differences and aim
to makeany
error a hollow rather than a hump.11. When glued remember this -
0.020" of
glass over corrugated ironwill not change the surface into an
ice rink so
sand your foam with along sanding block, a long straight edge
and along the
lines whichjoin the talking lines spanwise. Foam is much much
easier to sand
thaneither micro or glass. and get it to within 0.030" or so.
Use lightand
sand intelligently. One stroke of the sanding block will make
adifference.
Do not hard shell - this is a moronic process. Lets continue the
conversation when you get to glassing, there arelots of ways to
make that
simpler and easier as well. Hope this helpsJohn--- In
Q-LIST@... <Q-LIST%40yahoogroups.com>, "mtyquinn665"
<mquinn6@> wrote:>> I am trying VERY hard not to reinvent the
wheel but I
am attempting to > build the wing on a jig and see posting where
washout and
wing > alignment (of the foam) caused the final product to not
be as perfect
as intended. (any sanding to match the other foam indicates an
inacuracy
in following the template when hot wiring - then one sands to >
match and
you are left with an "original" airfoil)> > My thought is to
make a slot cut
(90 degrees perpendicular to the > surface) 1/2 inch deep at the
WL between
the foam sections and use a > 1/16" x 1" ( x width of the wing
at that point
minus 1 in or so) strip > of plastic as a key (this concept is
from years of
woodworking and what > we call "biskets"). > > To test for
levelness a equal
length wood skewer could be inserted > (using a small square to
insure
perpendicular to skin in 2 planes) > until it makes contact w/
the plastic
(prior to glassing)and a level > could be placed on top of the
skewers. > >
Does this make any sense?> > M.>

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Richard Hole <rickhole@...>
 

No, the wet technique doesn't require a lot of help, three is about the
normal crew for that work anyway, and with metering epoxy dispensors a
person to mix can help lay down the glass. The hard shell question for
them is merely a matter of weather. I must admit that surprised me.

--- In Q-LIST@..., Michael Quinn <mquinn6@...> wrote:


If they had only 2 or three people able to measure/mix and layup -
would they choose the hard? I read other sites and this seems to be
one of the arguments (reasons) for homebuilders (vs. production
builders) going w/ hardshell.


John ten
 

Hi Dave,

Goodness me!

What did you find?

John

--- In Q-LIST@..., Dave Dugas <davedq2@...> wrote:

Sorry John.....couldn't find them. Dave D

johntenhave <johntenhave@...> wrote: Sure,

check the presentation I posted this morning in the files section.

John


Dave Dugas
 

John,
I found a nice presentation on finishing composite aircraft but must have missed something. Dave D.

johntenhave <johntenhave@...> wrote:
Hi Dave,

Goodness me!

What did you find?

John

--- In Q-LIST@..., Dave Dugas <davedq2@...> wrote:

Sorry John.....couldn't find them. Dave D

johntenhave <johntenhave@...> wrote: Sure,

check the presentation I posted this morning in the files section.

John





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John ten
 

Dave,

I think that was the topic under discussion..
If you have any questions on the subject I will try and and answer them.

John


--- In Q-LIST@..., Dave Dugas <davedq2@...> wrote:

John,
I found a nice presentation on finishing composite aircraft but
must have missed something. Dave D.

johntenhave <johntenhave@...> wrote:
Hi Dave,

Goodness me!

What did you find?

John

--- In Q-LIST@..., Dave Dugas <davedq2@> wrote:

Sorry John.....couldn't find them. Dave D

johntenhave <johntenhave@> wrote: Sure,

check the presentation I posted this morning in the files section.

John





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