I am going to be applying silkspan over a carbon fiber/epoxy structure. I plan on attaching it with dope but do not know if that will work or if it will pull off. Some of the edges will be on carbon tubes, some will be on carbon fiber plates. Anyone had any experience?
bob branch
I've made a bunch of carbon-epoxy stuff will all sorts of epoxy. It's pretty easy to get along with, except for the splinters, which you know about by now. I have put several different things on it for finish. The only chemical problem I had was with mold release residue on some wheel pants. It left pinholes in the finish. If the carbon tubes are the material that people sell for pushrods, I suspect (because of how it smells when cut) that they are made with polyester resin, which may be soluble in dope thinner.
Silkspan might tear at sharp corners, but I can't imagine any other problems with it. I put it over my carbon-epoxy-tube flap leading edges without incident. It stuck fine.
Although some epoxy used now in aircraft composites is UV sensitive, I haven't had any problems. I used some bare-composite landing gear for ten years, and it still held up to my landings. Heat could be an issue if you use low-Tg resin, keep it black, and leave it in the sun. Room-temperature-layup props change pitch when left out on hot, sunny days. I keep my spares in the cooler and cover the one on my plane with a rag. If your parts are made from 250-degree or higher prepreg, I wouldn't think they'd get hot enough to soften.
Phil Granderson may have used a carbon tube structure in his recent electric planes. He might have some wisdom on covering and finishing.