I coated the inside of my molded shell with 2coats of nitrate dope thinned 50/50 to apply carbon veil and it shrunk up.....width wise, like it "humped" up so the edges dont line up. I wonder if I coat the outside if it will go back to original shape? Or just make formers?
Yes, that is exactly what happened to the turtledeck on my airplane- except it was assembled at the time. It caused severe "starved horse" effects. The solution (suggested by Ted Fancher) was to mix up some more nitrate but add plasticizer. Within 10 minutes, the problem got a lot better and it has stayed better since then. Unfortunately in my case, it also had negative effects on the adhesion of the paint, which led to some other problems later.
Note that Brodak sells two kinds of nitrate, tautening and non-tautening. Use non-tautening, of course.
If you are going to put something on the inside of sheeting or molded parts, use thinned epoxy and remove most of it by blotting or rolling with toilet paper to soak up the excess. That's a trick from the good old days - the epoxy fills the pores a bit, so the pores are more difficult to compress when the finish goes on the outside, reducing the possibility of it causing starved horse or other shrinkage issues.
Brett