Sailplane Construction Project Session #130
Comet Sailplane Project
Even though the first covering of the
fuselage will be Polyspan Lite, the Sailplane's pylon is far too complex a
shape to try to cover with Polyspan Lite. So I used white silk instead of
Polyspan Lite for the first covering of the pylon as well as the firewall.
As you can see below, with one piece of white silk I was able to cover
the complete left half pylon including the underneath side of the wing
saddle. I could have never accomplished this using Polyspan Lite. The
covering is still in process in this picture.
This shows the complete pylon (both sides)
covered in white silk with one coat of clear dope. Notice that the epoxy
fillet has almost disappeared behind the white silk covering.
I cut out a piece Polyspan Lite from the supply I
got from Larry Davidson that was 8" wide and 50" long to cover the left side
of the Sailplane's fuselage with. In the picture below, I have the Polyspan
Lite pretty much tacked down using only Acetone, a trick that Gene Wallock
passed on to me. The Acetone acts almost like a spot welder on the material.
You just touch a spot and the Polyspan Lite instantly sticks to the
structure. You can also recoat the tacked spot, lift the material and then
reattach it with no build up like you get with clear dope.
Using a heating iron, the material's fold creases
can be quickly taken out as you go along. Then you coat the perimeter with
clear dope and trim off the access. The heating iron is used to shrink the
Polyspan Lite and then one coat of 50/50 clear dope is put on as shown
below. As you can see, there is very little difference in appearance of the
white silk and Polyspan Lite.
In this close up, you can see how nicely the
Polyspan Lite went over the stringers that are attached to the forward
barrel planking with the array of fillets.
This picture shows the left side Polyspan Lite
covering with one coat of clear dope from a distance. I was also able to
cover the right side of the fuselage as well before I quit this
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