paint color


Cameron Camp <cameron@...>
 

I've heard you shouldn't paint your wings anything but white, does
anyone have an objective reference for this? I see a lot of white
planes, but I see also a Lancair factory demonstrator that was lipstick
red and was foam and glass construction. My plane will be hangared and
in a cool climate 95% of the time. How can you tell if a wing has
received sun-related structural damage?

Cameron
N87TQ


quickheads2 <groups@...>
 

Cameron,
White is the best color for heat dissapation, but people have definitely painted their airplanes different colors. The Q1 and Q2 plans talk about this here:

http://www.quickheads.com/q1-plans-chapter-19-page-19-1.html

and here:

http://www.quickheads.com/q2-plans-chapter-3-page-3-14.html

I think there is kind of a joke that goes around the composite builder communities that you have three choices for paint color. . . white, white, or white. However, ultimately the choice is the builders. Just realize that it is a safety concern, so don't be too flippant about the decision.

Hope this helps.

Warm regards,
Dan Yager
www.quickheads.com

--- In Q-LIST@..., Cameron Camp <cameron@...> wrote:

I've heard you shouldn't paint your wings anything but white, does
anyone have an objective reference for this? I see a lot of white
planes, but I see also a Lancair factory demonstrator that was lipstick
red and was foam and glass construction. My plane will be hangared and
in a cool climate 95% of the time. How can you tell if a wing has
received sun-related structural damage?

Cameron
N87TQ


Jim Patillo
 

Cameron,

Just touch a red car V.S. a white one on a 95 degree day. You may find your answer there.

Jim Patillo
N46JP Q200

--- In Q-LIST@..., Cameron Camp <cameron@...> wrote:

I've heard you shouldn't paint your wings anything but white, does
anyone have an objective reference for this? I see a lot of white
planes, but I see also a Lancair factory demonstrator that was lipstick
red and was foam and glass construction. My plane will be hangared and
in a cool climate 95% of the time. How can you tell if a wing has
received sun-related structural damage?

Cameron
N87TQ


uncleducati <cameron@...>
 

I'm using EZ-Poxy, is it as simple as calculating the average cure temp for this type of expoxy and not exceeding that? If the wing raises above the critical temp and then cools, will I have any structural weakness, or is it because the structure deforms and is no longer aerodynamic? I plan on using a wing cover with white fabric when parked on a hot ramp.

On Fri, 2009-04-17 at 18:26 -0500, bob wrote:
The answer is not the foam and glass but the resin system used.
Epoxy resin hardens at the highest temperature it has ever seen
and if it goes beyond that temperature it goes back into a plastic
state. Once cooled below that it now has that higher 'set' temp.
If your canard sees it's highest temperature on the ramp you could
well end up with something from wrinkled top skin to a gull wing.
I believe many Q fliers also support the fuselage while hangered
to take long term weight off of the canard and eliminate the
possibility of canard sag/gear geometry change.


Sam Hoskins
 

Cameron, just stick with white. IMHO "wing covers" is an impractical idea.
Follow the advice of 99.9% of the composite community.

The objective reference is Burt Rutan.

"How can you tell if a wing has received sun-related structural damage?"
Good question - you can't, at least until it's too late.

Stick with the plan, man.

Sam Hoskins
Q-200

On Fri, Apr 17, 2009 at 1:33 AM, Cameron Camp <cameron@...> wrote:



I've heard you shouldn't paint your wings anything but white, does
anyone have an objective reference for this? I see a lot of white
planes, but I see also a Lancair factory demonstrator that was lipstick
red and was foam and glass construction. My plane will be hangared and
in a cool climate 95% of the time. How can you tell if a wing has
received sun-related structural damage?

Cameron
N87TQ



Rick Hole <r.hole@...>
 

Sam knows. Please take our word for it.

Rick



_____

From: Q-LIST@... [mailto:Q-LIST@...] On Behalf Of
Sam Hoskins
Sent: Friday, April 17, 2009 9:41 PM
To: Q-LIST@...
Subject: Re: [Q-LIST] paint color








Cameron, just stick with white. IMHO "wing covers" is an impractical idea.
Follow the advice of 99.9% of the composite community.

The objective reference is Burt Rutan.

"How can you tell if a wing has received sun-related structural damage?"
Good question - you can't, at least until it's too late.

Stick with the plan, man.

Sam Hoskins
Q-200

On Fri, Apr 17, 2009 at 1:33 AM, Cameron Camp <cameron@campworkz.
<mailto:cameron%40campworkz.com> com> wrote:



I've heard you shouldn't paint your wings anything but white, does
anyone have an objective reference for this? I see a lot of white
planes, but I see also a Lancair factory demonstrator that was lipstick
red and was foam and glass construction. My plane will be hangared and
in a cool climate 95% of the time. How can you tell if a wing has
received sun-related structural damage?

Cameron
N87TQ



Mike Dwyer <mdwyer@...>
 

The fiberglass isn't the thermal weak point, the foam under the glass is.
White is the only color for me.
Mike Q200 N3QP


uncleducati wrote:

I'm using EZ-Poxy, is it as simple as calculating the average cure temp for this type of expoxy and not exceeding that? If the wing raises above the critical temp and then cools, will I have any structural weakness, or is it because the structure deforms and is no longer aerodynamic? I plan on using a wing cover with white fabric when parked on a hot ramp.

On Fri, 2009-04-17 at 18:26 -0500, bob wrote:

The answer is not the foam and glass but the resin system used.
Epoxy resin hardens at the highest temperature it has ever seen
and if it goes beyond that temperature it goes back into a plastic
state. Once cooled below that it now has that higher 'set' temp.
If your canard sees it's highest temperature on the ramp you could
well end up with something from wrinkled top skin to a gull wing.
I believe many Q fliers also support the fuselage while hangered
to take long term weight off of the canard and eliminate the
possibility of canard sag/gear geometry change.


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

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

Yahoo! Groups Links





uncleducati <cameron@...>
 

What is the structural difference between our wings and the factory Lancair, which is red? The way I understand it they would both experience roughly the same structural forces, possibly higher on the Lancair due to the increased weight and speed. I looked at the temperature graph in the Q2 manual, and if it's close to linear, the ambient temperature where peak surface temperature would possibly begin to deform the wing with red paint would be ~130 degrees F with still air and direct sunlight with no cover, are my calculations correct?

--- In Q-LIST@..., Sam Hoskins <sam.hoskins@...> wrote:
The objective reference is Burt Rutan.

"How can you tell if a wing has received sun-related structural damage?"
Good question - you can't, at least until it's too late.

Stick with the plan, man.

Sam Hoskins
Q-200


Doug Humble <hawkidoug@...>
 

I believe the Lancair wing is not a foam composite structure. It has ribs.

Doug "Hawkeye" Humble
A Sign Above www.asignabove.net
Omaha NE
N25974

----- Original Message -----
From: uncleducati
To: Q-LIST@...
Sent: Friday, April 17, 2009 11:51 PM
Subject: [Q-LIST] Re: paint color





What is the structural difference between our wings and the factory Lancair, which is red? The way I understand it they would both experience roughly the same structural forces, possibly higher on the Lancair due to the increased weight and speed. I looked at the temperature graph in the Q2 manual, and if it's close to linear, the ambient temperature where peak surface temperature would possibly begin to deform the wing with red paint would be ~130 degrees F with still air and direct sunlight with no cover, are my calculations correct?

--- In Q-LIST@..., Sam Hoskins <sam.hoskins@...> wrote:
> The objective reference is Burt Rutan.
>
> "How can you tell if a wing has received sun-related structural damage?"
> Good question - you can't, at least until it's too late.
>
> Stick with the plan, man.
>
> Sam Hoskins
> Q-200


Robert Bounds
 

Enough! Don't paint your airplane anything but white. The Lancair wing is far different from ours. They are made up of parts that are vacuum bagged and autoclaved at an elevated temperature using prepreg glass. Rutan designed the moldless method using a common, economical foam and room temperature cure epoxy specifically for the homebuilder. One of the compromises is that our epoxy has a much lower TG and our foam has a lower melting point. I like red airplanes but I I chose to build a Rutan airplane and they are white. Period. (Sorry for the rant)
Bounds

----- Original Message -----
From: uncleducati
To: Q-LIST@...
Sent: Friday, April 17, 2009 10:51 PM
Subject: [Q-LIST] Re: paint color





What is the structural difference between our wings and the factory Lancair, which is red? The way I understand it they would both experience roughly the same structural forces, possibly higher on the Lancair due to the increased weight and speed. I looked at the temperature graph in the Q2 manual, and if it's close to linear, the ambient temperature where peak surface temperature would possibly begin to deform the wing with red paint would be ~130 degrees F with still air and direct sunlight with no cover, are my calculations correct?

--- In Q-LIST@..., Sam Hoskins <sam.hoskins@...> wrote:
> The objective reference is Burt Rutan.
>
> "How can you tell if a wing has received sun-related structural damage?"
> Good question - you can't, at least until it's too late.
>
> Stick with the plan, man.
>
> Sam Hoskins
> Q-200


Mike Perry
 

Bluntly, you need to learn a lot more about this process before you continue posting. The moldless composite construction method developed by Rutan has limitations and one is color. Paint it white or a very light color.

A dark painted wing placed in the sun will change shape; that is a known method of changing a warped surface.

Mike Perry

uncleducati wrote:



What is the structural difference between our wings and the factory Lancair, which is red? The way I understand it they would both experience roughly the same structural forces, possibly higher on the Lancair due to the increased weight and speed. I looked at the temperature graph in the Q2 manual, and if it's close to linear, the ambient temperature where peak surface temperature would possibly begin to deform the wing with red paint would be ~130 degrees F with still air and direct sunlight with no cover, are my calculations correct?

--- In Q-LIST@... <mailto:Q-LIST%40yahoogroups.com>, Sam Hoskins <sam.hoskins@...> wrote:
The objective reference is Burt Rutan.

"How can you tell if a wing has received sun-related structural damage?"
Good question - you can't, at least until it's too late.

Stick with the plan, man.

Sam Hoskins
Q-200


Larry Severson
 

Bluntly, you need to learn a lot more about this process before you
continue posting.
This is true, but not the whole story. Every epoxy has a different Tg (breakdown temperature). The cure temp does not dictate the final Tg, in fact, it increases over time (about 2 weeks) to about 20 degrees higher. One of the things recommended is to post cure the item after several days at a higher temp. In the case of Aeropoxy, with proper post curing, the Tg goes up to 210 degrees F, which happens to be above the safe level for the foam. To achieve the 210 degree Tg, it is necessary to raise the temp of the part above 160 degrees for several hours.

Even if you don't post cure, the Tg will increase over time as it is exposed to summer temps. Unfortunately, if the skin temp exceeds the current Tg, damage (big) can occur unless the part is fully supported in the proper shape. [The fully supported feature is what allows the use of temperature to reform a distorted part to its proper shape.] This is highly possible in the Southwest US. Thus, the call for white or another light color, such as yellow or cream, is indicated.


Larry Severson
Fountain Valley, CA 92708
(714) 968-9852
larry2@...


uncleducati <cameron@...>
 

Thanks for all the technical answers, I was primarily asking a technical question, or several.
Thanks,
Cameron

--- In Q-LIST@..., "Robert Bounds" <rebounds@...> wrote:
Enough! Don't paint your airplane anything but white.