Sailplane Construction Project Session #71
Most of the wings and stabs on my R/C ships are
covered with UltraCote Lite. They get a light sanding and then with
carefully sticking the film down I am through. However, I could not cover
the classic Comet Sailplane with any kind of film
(sandwich wrap as Larry Davidson calls it).
I have waited most of my adult life to build the Comet Sailplane and
it simply has to be covered with silk. Having said that, there is a
tremendous amount of work in silking as you well know. To begin with, every
part of the structure that is going to be covered has to be dope three times
with light sanding between each of the coats. To make the silk covering
bullet proof (long lasting),
I first cover the structure with a base covering of Polyspan Lite
before applying the second silk covering. However as with everything, there
is a technique to covering with Polyspan Lite, which Larry Davidson has been
most helpful in instructing me on.
I began covering the horizontal tail this morning
around 9:00 a.m. and did not stop until 4:30 p.m. and I still have to cover
the top of the stab tomorrow morning. I started by covering both halves of
the elevator just get Larry's technique worked out. Once they were covered,
I gave each surface two coat of 50/50 nitrate dope. As you can see, the
technique worked very well.
On the stab, I started with the bottom of the
stab's undercambered surface this afternoon. In addition to the three coats
of 50/50 clear nitrate dope with light sanding between each of the coats, I
applied two more coats of unthinned raw nitrate dope to bottom edges of the
undercambered ribs to insure adherence of the Polyspan Lite covering. My
wife Sue took this picture of me working on the stab's bottom covering.
This is a picture of the stab's bottom covering
once I finished trimming the edges.
This is another shot of the bottom covering on
the three foot long stab.
In this picture, I am attempting to show you how
well the Polyspan Lite covering stuck to the bottom of the heavily doped
undercambered ribs. No dope has been applied to the covering yet. Tomorrow I
will cover the top of the stab and then dope both sides of the stab at the
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