I've never heard for that happening. If I mold something that isn't clay, but a hard sculpt, I'll usually have Rustoleum primer on it. If your material isn't pourous, and you are using silicone RTV rubber, you shouldn't really need to seal it.
I've had paint come off in a mold, due to a heavy surface texture, but never inhibit the cure. The only time I've seen rubber not cure is when I've used catalyst that has gone bad.
That's all I can tell you from what you've told me. Hope you can get it to work.
For some reason, every test ive done with any kind of paint/sealer on it, the rebound isnt curing properly.
The inside surface is staying wet. The smoothon site says use an 'acrylic' paint coat to seal it. I tried that today, It didnt work. Ill let the pieces sit all night and part of tomorrow, see if they cure.
Im at a total loss here. I need to get these helmet internals into a mold. I have ppl waiting on em
Thanks for the help, ill let you know how it turns out:/
I just read the Rebound 25 PDF from Smooth On. They say to seal it, use an acrylic lacquer. It also says not to use latex gloves as that will inhibit the cure. Most acrylic paints are latex acrylic. If you used a latex acrylic to seal it, it's not going to work. I'm not sure what they mean by acrylic lacquer, but sand off what you can, and try out the rattle can Rustoleum primer. It's a laquer base and hopefully should work. Try the rubber on a small test area so you don't waste anymore rubber.