Model Forum / Radio Controlled / Air Models / July 2003

Ahh - back to the good old days!

Yes, silk for models is just a thin, closely-woven fabric made of the
cocoons of silkworms.  To apply:

Paint the frame with a couple of coats of clear dope.  Sand off the fuzzies.

Wet the silk (not dampen - wet)  and lay it in the frame.  Flatten out as
much as you can.  Paint clear dope onto the silk where it needs to adhere to
the frame.  (Yes, the dope turns white and the mess looks awful.)

When the silk and dope are dry, the silk is tight as a drum.  Trim it and
apply clear dope over everything (this will make the white dope become
clear).  Do this on a dry day, or the dope will blush (turn white) all over.

There is a trick to trimming where silk goes over a sharp edge.  Bend the
silk over the edge, and hit the edge with a bit of 320 grit sandpaper.

From here, you can do any of the following:

Paint with auto body primer, sand wet, repeat until very smooth.  Then,
paint with colored dope, followed by a clear coat of butyrate dope to make
the covering fuel proof.  I've never done this, but I have seen the result
on a U-Control stunt plane.  Very pretty.

If colored silk was used (or if you like the clear-white look), just fuel
proof.  I used to do that with U-Control combat planes.

I have seen colored tissue put on over silk with thinner only.  Then, apply
the butyrate dope .  This is much lighter than paint.  The only problem is
that silk follows compound curves, and tissue does not.

Silkspan is just high-grade tissue.  Use much the same technique, except the
wet silkspan is applied with thinner to stick it down, then fuel proofed if
needed.

Silk is easy to repair.  Just dope the place for the patch, lay down a piece
of silk, then dope again.  If it is small, you don't need to worry about
water.

For the planes I build now, I use Monokote.  It's easier, never blushes,
etc.  I also use CA hinges instead of the under-over cloth hinges.

I wonder what the age of the glider is . . .

-- Mike