[Goemon]

Yes, I also think one part definitely has to bend. I work with carbon fiber everyday, and carbon/epoxy mix definitely bend, otherwise it would be nearly impossible to take the part out of the aluminium molds. I''ve also built EG machine a year ago and have some experience with that too. Using only PVA, without wax, was more than enough. But I wasn't trying to replicate surface plate as I had metal inserts.

Properly cured cf parts don't have nearly enough flex to allow them to release from rigid molds without molds release. Room temp cure cf parts will flex if they are made with too few layers and not left to cure and post cure properly. Properly cured cf parts are rigid and require proper mold release to be removed from the mold cleanly.

Nobody who knows what they are talking about recommends using pva on it's own. Literally nobody. Some use just wax but never just pva.

btw, being able to flex a part or the mold does not cause it to release without mold release. It only works that way with silicone molds because silicone doesn't bond to anything except glass and silicone. Try making a flexible mold using urethane rubber without using mold release. I guarantee that thing is never coming off.