UV damage


Allan Farr <afarr@...>
 

Some of the visible fibreglass on my plane (cockpit, elevator slots on canard, etc.) shows a lot of cloth & very little resin. Does anyone know if this is likely to be UV damage, or perhaps just a dry layup? Also, I would like some info on manufacturing the elevator trim system, is this available?
Allan F.
Q2 Rev 99% completed by others.


Mike Dwyer <mdwyer@...>
 

That is absolutely UV damage. I would scrap the plane as you don't know how much delamination/damage was done to the underlying foam. Your life is worth more than it would cost to build new parts.
Mike Q200 N3QP 1000+ hours

Allan Farr wrote:

Some of the visible fibreglass on my plane (cockpit, elevator slots on canard, etc.) shows a lot of cloth & very little resin. Does anyone know if this is likely to be UV damage, or perhaps just a dry layup? Also, I would like some info on manufacturing the elevator trim system, is this available?
Allan F.
Q2 Rev 99% completed by others.


Allan Farr <afarr@...>
 

Thanks Mike
Actually, I'm less worried now. The main area of UV damage (or dry lay-up) are the elevator slots (t/e of canard), so it seems to me that at worst I will just have to replace that (or maybe add an extra ply of bid on top?). I will get a local Varieeze builder to have a look. What brought this about is finding that the a/c doesn't have the black UV protection, just a yellow (ochre?) undercoat/filler, with gloss white on top. It's possible these paints have UV protection built in, but it would be good to know for sure as UV here in NZ is about as extreme as it comes (we live under a hole in the ozone). The a/c has previously had a stress test on the canard & wing which it passed with no "cracking or popping" & with the wings returning to their original positions, so I presume it must be basically sound.
Allan F

----- Original Message -----
From: Mike Dwyer
To: Q-LIST@...
Sent: Tuesday, 13 March 2007 12:39
Subject: Re: [Q-LIST] UV damage


That is absolutely UV damage. I would scrap the plane as you don't know
how much delamination/damage was done to the underlying foam. Your life
is worth more than it would cost to build new parts.
Mike Q200 N3QP 1000+ hours

Allan Farr wrote:
> Some of the visible fibreglass on my plane (cockpit, elevator slots on canard, etc.) shows a lot of cloth & very little resin. Does anyone know if this is likely to be UV damage, or perhaps just a dry layup? Also, I would like some info on manufacturing the elevator trim system, is this available?
> Allan F.
> Q2 Rev 99% completed by others.
>
>
>


quickieaircraft
 

Does anyone know if there is a decent way to inspect for UV damage once primer and finish is applied? I know...there shouldn't be any damage through the paint and primer, but...well, I think most of us still store our composite planes indoors just in case.

http://www.vafarchive.com/msg/rv10/t2002323000

--- In Q-LIST@..., "Allan Farr" <afarr@...> wrote:

Thanks Mike
Actually, I'm less worried now. The main area of UV damage (or dry lay-up) are the elevator slots (t/e of canard), so it seems to me that at worst I will just have to replace that (or maybe add an extra ply of bid on top?). I will get a local Varieeze builder to have a look. What brought this about is finding that the a/c doesn't have the black UV protection, just a yellow (ochre?) undercoat/filler, with gloss white on top. It's possible these paints have UV protection built in, but it would be good to know for sure as UV here in NZ is about as extreme as it comes (we live under a hole in the ozone). The a/c has previously had a stress test on the canard & wing which it passed with no "cracking or popping" & with the wings returning to their original positions, so I presume it must be basically sound.
Allan F

----- Original Message -----
From: Mike Dwyer
To: Q-LIST@...
Sent: Tuesday, 13 March 2007 12:39
Subject: Re: [Q-LIST] UV damage


That is absolutely UV damage. I would scrap the plane as you don't know
how much delamination/damage was done to the underlying foam. Your life
is worth more than it would cost to build new parts.
Mike Q200 N3QP 1000+ hours

Allan Farr wrote:
> Some of the visible fibreglass on my plane (cockpit, elevator slots on canard, etc.) shows a lot of cloth & very little resin. Does anyone know if this is likely to be UV damage, or perhaps just a dry layup? Also, I would like some info on manufacturing the elevator trim system, is this available?
> Allan F.
> Q2 Rev 99% completed by others.
>
>
>






Mike Dwyer
 

Many years ago I left an unprimed piece of fiberglass in the Florida sun as a test. After a while the resin went away leaving the white glass on the surface. I assume the resin basically evaporated. The elevator slot is a critical area, kind of like a mini wing spar so I'd be real careful there. Asking another builder if you should use a part that you know to be previously damaged is just trying to find someone else to help you justify a bad decision. If your building a tri-Q then there is less stress on the canard and you might get away with it. Putting a new lamination on top of a contaminated layer is at best a waste of time. Try laminating two plys together with one piece of glass exposed to one drop of water and see what happens...



I calculated that the Q200 canard has the equivalent of 4G on it when loaded to gross on the ground, plus it is supported by the wing tips. Load a Cessna to gross (not even 4X) and pick it up by the wing tips some time, you'll be buying some new wings. In other words your stress test may have been ok for flight loads but I seriously doubt you tested for landing loads.



There are old pilots and there are bold pilots... but there are no old, bold pilots.



Mike Q200 N3QP


________________________________

To: Q-LIST@...
From: quickieaircraft@...
Date: Tue, 12 Jul 2011 20:34:28 +0000
Subject: [Q-LIST] Re: UV damage




Does anyone know if there is a decent way to inspect for UV damage once
primer and finish is applied? I know...there shouldn't be any damage
through the paint and primer, but...well, I think most of us still
store our composite planes indoors just in case.

http://www.vafarchive.com/msg/rv10/t2002323000

--- In Q-LIST@...<mailto:Q-LIST@...>, "Allan
Farr" <afarr@...> wrote:

Thanks Mike
Actually, I'm less worried now. The main area of UV damage (or dry
lay-up) are the elevator slots (t/e of canard), so it seems to me that
at worst I will just have to replace that (or maybe add an extra ply of
bid on top?). I will get a local Varieeze builder to have a look. What
brought this about is finding that the a/c doesn't have the black UV
protection, just a yellow (ochre?) undercoat/filler, with gloss white
on top. It's possible these paints have UV protection built in, but it
would be good to know for sure as UV here in NZ is about as extreme as
it comes (we live under a hole in the ozone). The a/c has previously
had a stress test on the canard & wing which it passed with no
"cracking or popping" & with the wings returning to their original
positions, so I presume it must be basically sound.
Allan F

----- Original Message -----
From: Mike Dwyer
To: Q-LIST@...<mailto:Q-LIST@...>
Sent: Tuesday, 13 March 2007 12:39
Subject: Re: [Q-LIST] UV damage


That is absolutely UV damage. I would scrap the plane as you don't know
how much delamination/damage was done to the underlying foam. Your life
is worth more than it would cost to build new parts.
Mike Q200 N3QP 1000+ hours

Allan Farr wrote:
Some of the visible fibreglass on my plane (cockpit, elevator slots
on canard, etc.) shows a lot of cloth & very little resin. Does anyone
know if this is likely to be UV damage, or perhaps just a dry layup?
Also, I would like some info on manufacturing the elevator trim system,
is this available?
Allan F.
Q2 Rev 99% completed by others.





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


Larry Severson
 

Does anyone know if there is a decent way to inspect for UV damage once primer and finish is applied?

UV damaged fiberglass is milky. One could pick an exposed area and sand down to the fiberglass. Not good, but better than risking flying a plane UV damaged.

I know...there shouldn't be any damage through the paint and primer, but...well, I think most of us still store our composite planes indoors just in case.

Do you really know what the UV status of that hangered plane? How good was the original paint job? Tests that I have seen show that it takes about 5mm of UV protecting paint over the whole surface. But time of exposure and amount of UV encountered (10 years in Florida weather) needs to be significant with the 5mm protection.

I am working with PTI and a local technical college to establish optimum paint requirements. PTI produces mil spec paints, and is available at Aircraft Spruce,

--
Larry Severson
18242 Peters Ct
Fountain Valley, CA 92708
(714) 968-9852


quickieaircraft
 

Quick rule of thumb: supporting a monoplane by the wingtips loads the wingspar by something roughly equivalent to a 2G load. You can verify this with some simple math, or a piece of balsa and some weights.

UV damage is a given after a certain amount of time on unprimed surfaces. I'm wondering about the finished surfaces that we don't regularly inspect. Maybe I'm just being overly cautious, but I have to wonder, after 10-20 years, is the paint/primer still protecting against ALL UV damage? I'd want to have more than just a "wondering" to justify stripping and repainting.

Several labs have published on using IR spectroscopy to detect UV and heat damage and field-portable scanners are now available, though a little pricey. A business might be able to afford one, I might rent one if I had the option.

--- In Q-LIST@..., Mike Dwyer <q2pilot@...> wrote:


Many years ago I left an unprimed piece of fiberglass in the Florida sun as a test. After a while the resin went away leaving the white glass on the surface. I assume the resin basically evaporated. The elevator slot is a critical area, kind of like a mini wing spar so I'd be real careful there. Asking another builder if you should use a part that you know to be previously damaged is just trying to find someone else to help you justify a bad decision. If your building a tri-Q then there is less stress on the canard and you might get away with it. Putting a new lamination on top of a contaminated layer is at best a waste of time. Try laminating two plys together with one piece of glass exposed to one drop of water and see what happens...



I calculated that the Q200 canard has the equivalent of 4G on it when loaded to gross on the ground, plus it is supported by the wing tips. Load a Cessna to gross (not even 4X) and pick it up by the wing tips some time, you'll be buying some new wings. In other words your stress test may have been ok for flight loads but I seriously doubt you tested for landing loads.



There are old pilots and there are bold pilots... but there are no old, bold pilots.



Mike Q200 N3QP


________________________________
To: Q-LIST@...
From: quickieaircraft@...
Date: Tue, 12 Jul 2011 20:34:28 +0000
Subject: [Q-LIST] Re: UV damage




Does anyone know if there is a decent way to inspect for UV damage once
primer and finish is applied? I know...there shouldn't be any damage
through the paint and primer, but...well, I think most of us still
store our composite planes indoors just in case.

http://www.vafarchive.com/msg/rv10/t2002323000

--- In Q-LIST@...<mailto:Q-LIST@...>, "Allan
Farr" <afarr@> wrote:

Thanks Mike
Actually, I'm less worried now. The main area of UV damage (or dry
lay-up) are the elevator slots (t/e of canard), so it seems to me that
at worst I will just have to replace that (or maybe add an extra ply of
bid on top?). I will get a local Varieeze builder to have a look. What
brought this about is finding that the a/c doesn't have the black UV
protection, just a yellow (ochre?) undercoat/filler, with gloss white
on top. It's possible these paints have UV protection built in, but it
would be good to know for sure as UV here in NZ is about as extreme as
it comes (we live under a hole in the ozone). The a/c has previously
had a stress test on the canard & wing which it passed with no
"cracking or popping" & with the wings returning to their original
positions, so I presume it must be basically sound.
Allan F

----- Original Message -----
From: Mike Dwyer
To: Q-LIST@...<mailto:Q-LIST@...>
Sent: Tuesday, 13 March 2007 12:39
Subject: Re: [Q-LIST] UV damage


That is absolutely UV damage. I would scrap the plane as you don't know
how much delamination/damage was done to the underlying foam. Your life
is worth more than it would cost to build new parts.
Mike Q200 N3QP 1000+ hours

Allan Farr wrote:
Some of the visible fibreglass on my plane (cockpit, elevator slots
on canard, etc.) shows a lot of cloth & very little resin. Does anyone
know if this is likely to be UV damage, or perhaps just a dry layup?
Also, I would like some info on manufacturing the elevator trim system,
is this available?
Allan F.
Q2 Rev 99% completed by others.








Rick Hole
 

N1711Q is well into that age, built in 1982. When working on damaged areas
we sanding carefully to expose fiberglass in several areas. It looked very
good. That's a single data point, but it falls in line with similar repairs
on Velocities which are constructed with similar technique and materials.



For a plane stored in the sun the answer may be different.



I've seen awful messes for planes which were parked outside without primer,
or thinly primed, and became dumpster bait. I would not consider repairing
any surface in that condition.



Rick Hole


Paul Buckley
 

If the surface is primed and painted, but with no specific UV protection, would not any UV damage beneath the paint be made obvious by the paint surface dimpling and the glass weave showing through?

Paul Buckley
Cheshire
England

TriQ-200 under construction.
90% finished, 90% still to do.....

----- Original Message -----
From: Rick Hole
To: Q-LIST@...
Sent: Wednesday, July 13, 2011 3:53 AM
Subject: [Q-LIST] UV damage



N1711Q is well into that age, built in 1982. When working on damaged areas
we sanding carefully to expose fiberglass in several areas. It looked very
good. That's a single data point, but it falls in line with similar repairs
on Velocities which are constructed with similar technique and materials.

For a plane stored in the sun the answer may be different.

I've seen awful messes for planes which were parked outside without primer,
or thinly primed, and became dumpster bait. I would not consider repairing
any surface in that condition.

Rick Hole






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Version: 10.0.1390 / Virus Database: 1516/3760 - Release Date: 07/12/11


quickieaircraft
 

Probably, Paul, for severe damage, anyway.

My reading seems to indicate that UV protective properties of paint are very close to eachother for different paints, and that the protection really only starts to break down once the paint does.

This is a good thing: if the part wasn't UV damaged during the build and was then painted, then it's probably safe until the paint starts to flake or otherwise deteriorate.

Some UV absorbtion testing in http://www.ultralightnews.com/features/pdf/54NewsletterMarch2003.pdf

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

If the surface is primed and painted, but with no specific UV protection, would not any UV damage beneath the paint be made obvious by the paint surface dimpling and the glass weave showing through?

Paul Buckley
Cheshire
England

TriQ-200 under construction.
90% finished, 90% still to do.....


----- Original Message -----
From: Rick Hole
To: Q-LIST@...
Sent: Wednesday, July 13, 2011 3:53 AM
Subject: [Q-LIST] UV damage



N1711Q is well into that age, built in 1982. When working on damaged areas
we sanding carefully to expose fiberglass in several areas. It looked very
good. That's a single data point, but it falls in line with similar repairs
on Velocities which are constructed with similar technique and materials.

For a plane stored in the sun the answer may be different.

I've seen awful messes for planes which were parked outside without primer,
or thinly primed, and became dumpster bait. I would not consider repairing
any surface in that condition.

Rick Hole

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




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

No virus found in this message.
Checked by AVG - www.avg.com
Version: 10.0.1390 / Virus Database: 1516/3760 - Release Date: 07/12/11


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


Mike Dwyer
 

Quickieaircraft... Please post your name and experience signature at the end of each post. It helps us to understand who you are. Thanks.

You said that paints are all the same... Maybe true, but we rely on the dark primer to block the UV, not the top coat paint. The original post said he did not have a UV block primer so the top coat paint is irrelevant.

To Pauls comment, I'd expect the top coat paint to peel off as the fiberglass resin disappears underneath the non UV paint cover.

So, UV primer then white paint to block the ir heat from the sun.

Mike Q200 N3QP 1000hr


Sent from my Windows Phone
________________________________
From: quickieaircraft
Sent: Wednesday, July 13, 2011 9:00 AM
To: Q-LIST@...
Subject: [Q-LIST] Re: UV damage

Probably, Paul, for severe damage, anyway.

My reading seems to indicate that UV protective properties of paint are very close to eachother for different paints, and that the protection really only starts to break down once the paint does.

This is a good thing: if the part wasn't UV damaged during the build and was then painted, then it's probably safe until the paint starts to flake or otherwise deteriorate.

Some UV absorbtion testing in http://www.ultralightnews.com/features/pdf/54NewsletterMarch2003.pdf



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

If the surface is primed and painted, but with no specific UV protection, would not any UV damage beneath the paint be made obvious by the paint surface dimpling and the glass weave showing through?

Paul Buckley
Cheshire
England

TriQ-200 under construction.
90% finished, 90% still to do.....


----- Original Message -----
From: Rick Hole
To: Q-LIST@...
Sent: Wednesday, July 13, 2011 3:53 AM
Subject: [Q-LIST] UV damage



N1711Q is well into that age, built in 1982. When working on damaged areas
we sanding carefully to expose fiberglass in several areas. It looked very
good. That's a single data point, but it falls in line with similar repairs
on Velocities which are constructed with similar technique and materials.

For a plane stored in the sun the answer may be different.

I've seen awful messes for planes which were parked outside without primer,
or thinly primed, and became dumpster bait. I would not consider repairing
any surface in that condition.

Rick Hole






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

No virus found in this message.
Checked by AVG - www.avg.com
Version: 10.0.1390 / Virus Database: 1516/3760 - Release Date: 07/12/11




Richard <mylittlemgb@...>
 

Okay here is my 2 cents worth and many years of painting and composit work. As long as the top coat is opaque color you have UV protection and the glass will not break down. Remember all colors of paint start with white. As far as paint peal this is due to poor prep work before the paint is applied. So as long as the glass has had some king of paint on it, it is protected. The time to worry is when you see blisters in the glass from delamination. We have a fabric covered homebuilt close to me that is flown weekly painted in house latex paint and sits on the flight line tie downs. Covering is now 20+ years old and still passes the punch test. So in short if it has paint on it there is no reason to believe it to be bad.

Richard
FLAPs

--- In Q-LIST@..., Mike Dwyer <q2pilot@...> wrote:


Quickieaircraft... Please post your name and experience signature at the end of each post. It helps us to understand who you are. Thanks.

You said that paints are all the same... Maybe true, but we rely on the dark primer to block the UV, not the top coat paint. The original post said he did not have a UV block primer so the top coat paint is irrelevant.

To Pauls comment, I'd expect the top coat paint to peel off as the fiberglass resin disappears underneath the non UV paint cover.

So, UV primer then white paint to block the ir heat from the sun.

Mike Q200 N3QP 1000hr


Sent from my Windows Phone
________________________________
From: quickieaircraft
Sent: Wednesday, July 13, 2011 9:00 AM
To: Q-LIST@...
Subject: [Q-LIST] Re: UV damage

Probably, Paul, for severe damage, anyway.

My reading seems to indicate that UV protective properties of paint are very close to eachother for different paints, and that the protection really only starts to break down once the paint does.

This is a good thing: if the part wasn't UV damaged during the build and was then painted, then it's probably safe until the paint starts to flake or otherwise deteriorate.

Some UV absorbtion testing in http://www.ultralightnews.com/features/pdf/54NewsletterMarch2003.pdf



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

If the surface is primed and painted, but with no specific UV protection, would not any UV damage beneath the paint be made obvious by the paint surface dimpling and the glass weave showing through?

Paul Buckley
Cheshire
England

TriQ-200 under construction.
90% finished, 90% still to do.....


----- Original Message -----
From: Rick Hole
To: Q-LIST@...
Sent: Wednesday, July 13, 2011 3:53 AM
Subject: [Q-LIST] UV damage



N1711Q is well into that age, built in 1982. When working on damaged areas
we sanding carefully to expose fiberglass in several areas. It looked very
good. That's a single data point, but it falls in line with similar repairs
on Velocities which are constructed with similar technique and materials.

For a plane stored in the sun the answer may be different.

I've seen awful messes for planes which were parked outside without primer,
or thinly primed, and became dumpster bait. I would not consider repairing
any surface in that condition.

Rick Hole

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




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

No virus found in this message.
Checked by AVG - www.avg.com
Version: 10.0.1390 / Virus Database: 1516/3760 - Release Date: 07/12/11








Mike Evans
 

I recently painted my fuselage (only - the wings were alrady painted with a
final color coat) with an ACS product called Smooth Prime, a UV filler /
primer (part # 09-28290). My point is that this product is white, and seems
to be an excellent filler and it's water-based.
I guess I'm looking for confirmation that this is an acceptable UV shield
since I hear everyone discussing a black (carbon) UV product.

Mike Evans, Still building Tri-Q200 in LA


Fisher Paul A. <fisherpaula@...>
 

Mike,
You really need to look at the specifications for the product. When my plane was painted (over 20 years ago!), I used a base coat clear coat system. In that case the UV barrier was in the CLEAR portion - not the color. Apparently the system was designed that way so the color didn't fade. I'm not sure what the magic was, but it has held up great for a long time! So you can't judge UV blockage by color alone.

Just my $0.02...

Paul A. Fisher
Q-200, N17PF


From: Q-LIST@... [mailto:Q-LIST@...] On Behalf Of Mike Evans
Sent: Wednesday, July 13, 2011 14:19
To: Q-LIST@...
Subject: Re: [Q-LIST] UV damage



I recently painted my fuselage (only - the wings were alrady painted with a
final color coat) with an ACS product called Smooth Prime, a UV filler /
primer (part # 09-28290). My point is that this product is white, and seems
to be an excellent filler and it's water-based.
I guess I'm looking for confirmation that this is an acceptable UV shield
since I hear everyone discussing a black (carbon) UV product.

Mike Evans, Still building Tri-Q200 in LA


Larry Severson
 

Some top coats have UV protection, even clear coats. I am working with
PTI paints. CPP is approaching the equivalent of 10 years of UV impact
under exposure to Florida weather (UV, temp, and rain all part of the
test cycle). Once all of the results are finished, I will post the
results. There will be no guess work. All of the research is being done
to the best university standards using top quality test equipment.

On 7/13/2011 8:53 AM, Mike Dwyer wrote:


Quickieaircraft... Please post your name and experience signature at
the end of each post. It helps us to understand who you are. Thanks.

You said that paints are all the same... Maybe true, but we rely on
the dark primer to block the UV, not the top coat paint. The original
post said he did not have a UV block primer so the top coat paint is
irrelevant.

To Pauls comment, I'd expect the top coat paint to peel off as the
fiberglass resin disappears underneath the non UV paint cover.

So, UV primer then white paint to block the ir heat from the sun.

Mike Q200 N3QP 1000hr
--
Larry Severson
18242 Peters Ct
Fountain Valley, CA 92708
(714) 968-9852


One Sky Dog
 

UV damage only affects epoxy and foam the glass is unaffected. You can see
the damage as the epoxy gets dull and powdery or flakes off the glass
fabric. Look at the backs of fiberglass signs and backboards, you will see
fiberglass strands where the matrix has been weathered away. first the sun
breaks it down then the wind rain dirt scrub it off.

Non UV blocker paint may not protect it and if the paint is undamaged it
would certainly lose its grip on the epoxy.

Damaged areas can be removed and replaced if the damage is severe but where
the damage is, is vital on deciding repair or scrap. Minor damage can be
sanded out to sound material and replaced with a like layup do not overbuild
the repair.

Regards,

Charlie Johnson
Ogden, Utah

In a message dated 7/13/2011 4:36:25 A.M. Mountain Daylight Time,
paulbuckley@... writes:

If the surface is primed and painted, but with no specific UV protection,
would not any UV damage beneath the paint be made obvious by the paint
surface dimpling and the glass weave showing through?

Paul Buckley
Cheshire
England

TriQ-200 under construction.
90% finished, 90% still to do.....


----- Original Message -----
From: Rick Hole
To: Q-LIST@...
Sent: Wednesday, July 13, 2011 3:53 AM
Subject: [Q-LIST] UV damage



N1711Q is well into that age, built in 1982. When working on damaged areas
we sanding carefully to expose fiberglass in several areas. It looked very
good. That's a single data point, but it falls in line with similar repairs
on Velocities which are constructed with similar technique and materials.


One Sky Dog
 

Smooth Prime the new formula but several years on the market has UV blocker
in it.


_http://www.aircraftspruce.com/catalog/cmpages/09-28290.php_
(http://www.aircraftspruce.com/catalog/cmpages/09-28290.php)

Regards,

Charlie Johnson
Ogden, Utah

In a message dated 7/13/2011 1:18:34 P.M. Mountain Daylight Time,
rranch524@... writes:

I recently painted my fuselage (only - the wings were alrady painted with
a
final color coat) with an ACS product called Smooth Prime, a UV filler /
primer (part # 09-28290). My point is that this product is white, and
seems
to be an excellent filler and it's water-based.
I guess I'm looking for confirmation that this is an acceptable UV shield
since I hear everyone discussing a black (carbon) UV product.

Mike Evans, Still building Tri-Q200 in LA


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



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

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

Yahoo! Groups Links


Richard Thomson
 

Hi Mike.

Can you explain your statement

I calculated that the Q200 canard has the equivalent of 4G on it when loaded to gross on the ground, plus it is supported by the wing tips. ?

It's a few years since I have played with Aero loads, but to have G do you not need to have movement or acceleration ? So at Design gross weight is it not still 1G loading ?

Do we know what Burt and successors originally stressed the spars to take ( on the Long eze he said it was 17 G ) ?



Also has there been any main wing or Canard failures in flight ? I only remember 1 problem which was elevator mount failure wasn't it ?

How much damage is caused to the spar caps when the outer layers are not or become no longer painted ?
Can the UV penetrate the outer plies to that depth and damage the spar ? What testing has been done to prove this ?

Not a problem for you hot climate boys, but from my experience I noted that the old style UV layer will unfortuanately absorb moisture if there are any pinhloes in the paint layer, which softens it and then it sheers under the outer paint layer, the paint can then be locally stripped in sheets, yet under the remaing black the weave surface is just like new with no damp or UV damage.
That's why I have used good quality 2 pack epoxy primer and 2 pack polyurathne top coat to refinish, as it's specification states it is a UV barrier and its protected from virtually everything including salt water.

Richard Thomson

TriQ200
Getting closer every week.

UK


Mike Dwyer
 

Hi Richard,

For the standard Q's (not Tri-Q)... If I remember my calculations of 20 years ago, when a wing develops 1G of lift it is doing so with the lift distribution over the entire wing surface. If you lift a plane by only the wing tips that is basically equivalent to a distributed 2G load. If you have 2 wings and lift the plane with only one of them (the canard) then you have the equivalent of 4G on that one wing. If you bounce up and down a bit while getting in the plane (we all do) then the loaded G equivalent is probably more like 6G on the canard. Nobody use the Q as a trampolene please!



The Q200 canard I heard was good for 30G and the main wing 15G,,, tho never tested anywhere near this. The most the plane can pull in flight is about 4G, but I suppose a fast updraft could put more load on the plane?



No correctly built airplane has ever come apart in flight to my knowledge. I say it that way because one main wing broke after an incorrect repair job.



UV to my knowlege doesn't penetrate very far, kinda breaks down the first molecule it hits.



As for your paint theory try a different thought. No idea if this is right or not. I understand fiberglass resins outgass for their entire life. If you seal over it with a super non-porus sealant then when it outgasses it will blow the paint off. My theory is use cheap paint cause we're all going to be repainting in 15 years! My paint bubbled right off as you described. Darn, I got 15 years on the first paint job and now have 11 on the second. Don't tell me that I'll have to do it again in 4 more years! see: http://www.warnerair.com/q200/re1.html



Mike Q200 N3QP



________________________________

To: Q-LIST@...
From: richard@...
Date: Sun, 17 Jul 2011 20:49:24 +0100
Subject: [Q-LIST] Re: UV damage



Hi Mike.

Can you explain your statement

I calculated that the Q200 canard has the equivalent of 4G on it when
loaded to gross on the ground, plus it is supported by the wing tips. ?

It's a few years since I have played with Aero loads, but to have G do
you not need to have movement or acceleration ? So at Design gross
weight is it not still 1G loading ?

Do we know what Burt and successors originally stressed the spars to
take ( on the Long eze he said it was 17 G ) ?

Also has there been any main wing or Canard failures in flight ? I only
remember 1 problem which was elevator mount failure wasn't it ?

How much damage is caused to the spar caps when the outer layers are
not or become no longer painted ?
Can the UV penetrate the outer plies to that depth and damage the spar
? What testing has been done to prove this ?

Not a problem for you hot climate boys, but from my experience I noted
that the old style UV layer will unfortuanately absorb moisture if
there are any pinhloes in the paint layer, which softens it and then it
sheers under the outer paint layer, the paint can then be locally
stripped in sheets, yet under the remaing black the weave surface is
just like new with no damp or UV damage.
That's why I have used good quality 2 pack epoxy primer and 2 pack
polyurathne top coat to refinish, as it's specification states it is a
UV barrier and its protected from virtually everything including salt
water.

Richard Thomson

TriQ200
Getting closer every week.

UK





One Sky Dog
 

5mm (~.200 inches) are you lucid?

One Sky Dog

In a message dated 7/17/2011 6:51:21 P.M. Mountain Daylight Time,
larry2@... writes:

Does anyone know if there is a decent way to inspect for UV damage once
primer and finish is applied?

UV damaged fiberglass is milky. One could pick an exposed area and sand
down to the fiberglass. Not good, but better than risking flying a plane
UV damaged.

I know...there shouldn't be any damage through the paint and primer,
but...well, I think most of us still store our composite planes indoors
just in case.

Do you really know what the UV status of that hangered plane? How good
was the original paint job? Tests that I have seen show that it takes
about 5mm of UV protecting paint over the whole surface. But time of
exposure and amount of UV encountered (10 years in Florida weather)
needs to be significant with the 5mm protection.

I am working with PTI and a local technical college to establish optimum
paint requirements. PTI produces mil spec paints, and is available at
Aircraft Spruce,

--
Larry Severson
18242 Peters Ct
Fountain Valley, CA 92708
(714) 968-9852



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