I experience a lot of problems with surface pinholes while using Phenolic resin for hand layup (resole). As a result, the surface has to be sanded down, primed, sanded down again, primed again and then painted.
I was wondering if using an in-mould primer or a surfacing film would give me a pin hole free surface ready to be painted and help me get rid of the whole tedious process.
or whether using novalak could improve. Even single vacuum bagging doesn’t help with the situation.
I havent used phenolics for hand laminating but have used them with pre-preg work. A large problem, particularly with elevated cure temperatures with phenolics is the moisture. Moisture is formulated by the curing process and is a likely cause for pinholes.
Have you degassed your resin?
I havent used degassing since I assumed it would make no difference in hand lamination.
With prepregs, did you ever use an in mould primer? do you think that makes a difference too?
With surface pinholes, in my knowledge they occur due to trapped air and like you said the water produced.
I was also thinking of using the surface paste from momentive.
You’re right, it doesnt make a huge difference with wet lay particularly depending on how you get the resin into the cloth, so its only if you have the rest of your process sorted really. Are you brushing the resin on?
No, didnt use an in-mould primer with the phenolic pre-preg.