I have a 6-piece mould made from the Unimould system. There are a few minor imperfections along the parting lines that needs to be adressed before using the mould.

Hi Lasse,

you can grind back a little then add some more tooling gel ( remember to release coat the other faces) and then sand back.

you could cover the repair and it will cure ok or add some solution wax to give a dry surface.




don't go mad trying to get perfect joins, you need to seal the flanges with silicon and this does a good job of filling small voids, use the automotive type but if you are using easy lease go careful at these joins as it slightly dissolves the silicon.

So you mean to say automotive high temp silicone can be used as a mould sealant for prepreg duty in around 100C? No bad chemical reactions vs. the epoxy?

Ah yes sorry I'm relating back to infusion.

you can get away with simply applying release agent when using pre peg.




maybe some of the more experienced can shed some light on this question.

You would normally envelope bag the entire mould with pre-preg, so you don't need to seal the flanges. 

Yes, I'll envelope bag the whole thing. My issue is these small broken off pieces along the mould parting lines...but I guess I'll use some Unimould tooling gelcoat to fix these. What exactly is the kind of "wax" to be mixed into the gelcoat, and at which rate?

You need 'wax-in-styrene additive', and you normally add it at 5%. 

Just a few small pieces, maybe 1mm deep, a few mms long here and there. Enough that I'm afraid if I ignore them then maybe I'll be deep into the fiber trying to flatten down the finished prepreg parts.

Racing motorcycles!

I doubt it. Cracks like that are too small for the carbon to go into, so it would just be resin. You could easily scrape that flashing off with a sharp knife and then give it a quick flat with 1200, you shouldn't bite into the fibres at all.