I am not used to using epoxy resins and my first attempt with carbon fiber failed due to the epoxy bonding with a very well waxed polyester gelcoated mould. Im wondering if i had made a mistake or polyester gel is unsuitable to use as a moulding surface for epoxy resin ? Any help will be really apreciated!
Is this a new mold or a seasoned mold?
Epoxy bonds much better to everything…including release surfaces. The problem probably wasn’t the gel-coat but that you needed PVA along with the wax. If the mold is new then you MIGHT only need to use PVA for the first 3-4 uses. With epoxy resins you many need to always use it.
I’m assuming that you applied the wax properly.
it was a brand new mould that is now scrap haha and yes i use polyester alot and it is always a good release. okay i never really use PVA but i will definately try this next time thank you for the help!
With polyester and epoxy I never had any problems. It only bonds mechanical, so the wax alone is good enough. polyester-polyester is somewhat more tricky the first few pulls, and epoxy-epoxy gives a real good adhesion without anything but a good layer of PVA. A good post-cure on the epoxy mould will solve the problem too, chemical bonding is a bitch with moulds…