I also covered the wing with Sig Koverall today. This stuff works so well it's scary. First, I applied full-strength, unthinned nitrate dope to the LE, TE, center section and tips using a foam brush. I put on about three coats, until the surface looked shiny. Then I sanded off any lumps or runs until everything was smooth. I laid the Koverall over the wing half and brushed straight thinner on top of the fabric. Using my finger, I rubbed the thinner through the fabric until it dissolved the nitrate dope beneath. This adheres the fabric to the wing.
I attached the covering the same way I would with plastic film, pulling and tacking it down while stretching it tight. Unlike iron-on film, it is very easy to release the fabric with more thinner if you need to reposition an area or pull out a wrinkle. Once I had the Koverall completely adhered I let the dissolved dope dry for a few minutes and then shrunk it tight over the open bays with my iron. If any wrinkles or loose spots remain, you simple wet the area with thinner and rub it down.
Next, I sprayed on three light coats of clear butyrate dope to fill the weave. Koverall fills a lot faster than silk, which can take as many as eight coats to completely fill. It also doesn't pull and run like silk can. The next step is to put on a few coats of the primer and get rid of the line where the fabric stops. If you've ever thought about an alternative to iron-on film, please try Koverall. It's incredibly user-friendly stuff. And, it won't sag or bubble over time. What's a couple more hours work for a finish that will last fifty years?
Also, thanks to RCU for letting members devour so much space with unlimited images!