Re: Why is White So Sacred. . .


Rick Hole
 

The problem typically is that the heat absorbed into the foam cores causes
the core to shrink, and the boundary between the core and the fiberglass
(which is comparatively unshrinking at that level of heat) causes a
delamination with the resulting symptom of an air bubble between glass and
foam.



Fiberglass parts at a somewhat higher temperature can creep, especially
those under stress such as landing gear and should be kept white if exposed
to the heat of the sun.



Velocity builders typically do not post cure. It was tried and did not
solve the issue. You can get away with bright, and maybe even dark colors
on vertical surfaces, but I have seen enough delaminations on horizontal
surfaces that I would not consider doing them.



Velocity materials and construction techniques are very similar to our Q's.

Rick Hole

Built both Q and Velocity



_____

From: Q-LIST@yahoogroups.com [mailto:Q-LIST@yahoogroups.com] On Behalf Of
Wired Calvin
Sent: Wednesday, November 09, 2011 5:16 AM
To: Q-LIST@yahoogroups.com
Subject: Re: [Q-LIST] Why is White So Sacred. . .





Basic white is the majority color on most canard types due to epoxy
characteristics when heated which can result in creeping or dimensional
changes in parts. The melting temperature of foams used in construction is
also a concern.

I remember talking to the owner of a beautiful Velocity at Sun n' Fun on a
95 degree day, the plane was parked on the tarmac in full solar loading. It
had a custom paint job with every color of the rainbow in candy colors with
large metal-flake underneath just as you would see on a custom show car.
Deep greens reds, and blues with hues changing throughout large accent
sweeps. I asked the owner if he was concerned about the solar loading and
temperature of the darker colors and his reply was no issues to date. When
asked how he achieved the resilience to temperature he stated after
painting the aircraft he pulled it out in the sun for heat curing in
increments of several minutes and then he would bring it back inside and
let it cool. He gradually increased the soak times until he could leave it
out all day. He had the fuselage sides painted with large flowing ribbons
over white and the winglets were done with smaller ones. I'm
not familiar with the Velo's construction materials, or if they post cure
their parts at elevated temperatures but you may want to look into it.

There are a few yellow, light yellow, light tan, EZ's and of course Dick
Rutans sky blue, EZ. There is an award winning Q2 for sale in our area that
has a lot of red on it.

David Rowe
622EZ

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