Velocity Colors

[SeansullTX]

Hello All,

 

I am curious as to what colors are "acceptable" for a velocity other than white for the base color. I know the darker colors are OUT especially since I am in Texas and the heat gets unbearable here.

 

I want mine to be different and definitely not white if possible.

 

Any thoughts and explanations of why or why not are appreciated!

[Big Steve]

White is the only approved color for a "home cured" epoxy airplane. I live in Idaho it is a lot cooler here than Texas and I would only paint my plane white on the top. Colors other than white can raise the skin temperature of the plane to an unacceptable temperature. But::: it is your plane go ahead and paint it anything you want In Texas I bet it wont make one summer without drooping a wing if the color is dark enough. STeve

[jwright]

Seansull - Check this graph out; I don't know what source data was used to create the curves, but it will give you a general idea of what colors are 'more good' v. 'more bad'... http://www.maddyhome.com/cozy/chapter?c=25&s=5

 

(credits to the author of the web page.)

[emteeoh]

Check with the factory about this. The "problem" with the velocity is that the materials used in the fuselage are not the same as what you're using elsewhere, and it has a higher temperature tolerance. As a result, what is not acceptable for the wings, canard, and a LEZ or Cozy, *MAY* be acceptable for the fuselage. I think they're discouraging dark colours, but they're not insisting on white.

[Waiter]

I performed some preliminary color temperature testing on my LongEZ.

 

Look at:

 

http://www.iflyez.com/LongEZ_Retrofit_JUN_07.shtml

 

Scroll down to the 9 June entry.

 

Waiter

[brainfart]

I don't know anything about the materials used for velocity construction, but every time I see someone using epoxies like West System for aircraft construction this creeps me out. Look it up, the Tg and heat distortion temperatures for West System are below 50°C (you do the conversion ). In other words, that epoxy gets pretty soft even when the aircraft is painted white. It's not just West System, some of the other "approved" epoxies aren't much better. Then again without proper heat treatment (which doesn't seem to be high on most builders' to-do list either) even MGS L285 will not reach its final Tg of 90-105°C.

[Big Steve]

Why would the tg. of the different epoxies freak you out. These planes are well designed they are not falling out of the air because of week epoxy. The rule to epoxy airplanes is paint them white. If you want a colored airplane build a wood one or a metal one. It is simple and easy STeve

[brainfart]

> Why would the tg. of the different epoxies freak you out.

 

Because the mechanical properties of epoxies and other polymers change drastically above Tg. The polymer turns from a hard solid into a rubbery, soft consistency.

West for example has a Tg of 120-140F. Even a completely white plane will heat up above that temperature in summer.

 

> These planes are well designed they are not falling out of the air because of

> week epoxy.

 

That no canard plane has crashed yet as far as we know doesn't mean that someone, someday might crash due to material fatigue caused by above-Tg flying, or that there haven't been any incidents with normal planes.

[HardKnox]

Hey, Sean. In the Cozy plans there's a chart that shows the heat absorption of different colors. I'll show you next time we get together. While the plans say that white is the only approved color for a Cozy, I do recall that yellow was the next lowest heat absorption. The dual engine cozy built in Venezuella had yellow on top. I can't recall the other colors at the moment, but it wasn't intuitive. Orange, for example, was way up there in heat absorption.