ORIGINAL: cutaway

''If you used Sig or Brodak, I don't think you would ever get out the sags and wrinkles.''

<span style="color: #ff0000">The line above seem to show a thought but not an experience.
It also bring up the question "What is shrinking and getting tight? The material (fabric) or the dope ? or both ?</span>

I've been using Dharma's 5mm Habotai and covering dry. 3 thinned coats of Sig nitrate to fill the weave some, then 2/3 coats of Supercoat and its tight as a drum.

<span style="color: #ff0000">All dopes I have used over the years do some thightening.
</span><span style="color: #ff0000">I was curious if polyester do thighten and I tried to see the effect of heat on a covering of a horizontal tail (stab and elev). Any heat applied did not seem to do enough to talk about. I used a hair drier 1500 watts and ended up with the dier acually touching the material and waiting for any noticeable results. Nothing worth talking about was evident (At least you read the method I used).
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<span style="color: #ff0000">Now it might be helpfull to read the following ___

I apply the fabric by gluing the perimeter. I make sure there is no obvious winkles but I do not try to do any tight pulling. Just nice and smooth without winkles. The dope does the tightening.
When applying the first coat the fabric goes all loose and wrinkled as it is wetted by the dope. It looks like a catastrophy. Soon it all tightens up as the dope cures. he second coat usually do the same as it fuses into the first coat but soon again tighten up. As more coats are added the fusion does not reach right through and less wrinkling is happening.
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<span style="color: #ff0000">
Some basic thinking ____by Zor ____

A thread of fabric has a certain tensile strength. try to break a size 10 sewing threads. Be careful, you could cut your hands seriously particularly if you try to jerk it from loose and give it a "wham" rapidly.
For a fabric to tear each thread has to break and that can only happen in tension.

If each thread of the fabric is soakedin or surrouned by an adhesive and bound to the wood (or any substrate) it gives the wood structure considerable strength. That adhesive in our process is the nitrate dope ability to penetrate and bind each thread to the structure.

Polyester, nylon and silk are the preferred fabric but be careful about silk.
While genuine silk made by the worms is recognized as having the best strength to weight ratio, the silk available in stores these days is not genuine silk from the worms. It is a fabric which imitates the look, appearance and touch of genuine silk and has different characteristics.
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This was exactly what I said about Thai Silks vs. Dharma. You quoted what I said about Thai Silks, which is pre-shrunk. Dharma, as I said, is not, so it shrinks.

So to repeat, if you use Thai Silk with Sig or Brodak, you probably won't be able to get it taut. Dharma is a different matter because it is not pre-shrunk.

<span style="color: #ff0000">You probably won't be able to get it taut. ( line above) . . . .
All the dopes brands I have used over the years, all ended up tightening (tautening).
That has been so even on knitted silk as compared to woven.
Some wings were covered with old ladies silk stockings just pulled over the wing from tip to root.
No cutting, just pull like a lady put on her stockings and dope it.

</span>Jim