Surely you have read the manual's admonitions regarding color (or colour if
you prefer). If not here it is verbatim:
**********
Colour
The finished colour of the composite aircraft can affect its structural
strength and longevity.
Epoxy resins and foam are all sensitive to high temperatures. Room
temperature curing epoxies soften and lose their strength and rigidity at
only moderate temperatures 70 (160F). The sun is a source of heat. In
still air on a hot sunny day it is possible to obtain surface temperatures
that approach 105C (220F) on a black aircraft. The colour of the surface
determines how much solar heat it will absorb. White surfaces absorb very
little (10%) of the sun's heat whilst a black surface absorbing much more
(95%) will heat up greatly.
The accompanying graph (not included here because it is a graphic) shows the
relationship between colour and surface temperatures.
White has been chosen as the only colour for fibreglass sailplanes to
preclude any possibility of excess temperature due to solar heating. The
same criterion applies to the Europa: white is the only recommended colour.
Trim colours on the undersides, vertical surfaces and non critical areas
(wing and fin tips) are permitted. Avoid span-wise stripes on the wings as
these may trip the boundary layer destroying the laminar flow and create
unwanted drag.
**********
For epoxy composites, as for most structural materials, there is not
actually a fixed temperature but rather a range of temperature over which
the material gradually loses strength. Any (repeat for emphasis: any) color
other that white reduces the strength of the composite material at any
ambient temperature so you can expect the structure of a yellow Europa to be
weaker than a white one. If you operate only out of airports that never get
warm, no problem. Otherwise consider wearing a parachute any time you fly
because the strength of your aircraft will be (not: might be) compromised.
In re: the bolts
Why worry about paint? Replace them all with stainless steel fasteners that
will always look good and don't need any corrosion protection from paint.
Best regards,
Rob Housman
A070
----- Original Message -----
From: "John Cliff" <john@crixbinfield.freeserve.co.uk>
Subject: RE: Calling All Cars ....
> Forwarded from the bounce bin. Message is from
> "kbcarpenter" <kbcarpenter@att.net>
>
> ************************************************************
>
> Got the plane on it's own wheel. It is all painted in primer and ready to
> go with some color. I am going with a pale yellow base coat then decorate
> on top of that. When do I paint the heads of the bolts?
> Ken Carpenter
> A123
>
>
|