Hi, I wonder what’s the difference between epoxy gelcoat and polyester gelcoat ?
I have been working with epoxy gelcoat and epoxy resin for molds but find it rather expensive.
Is it possible to use polyster gelcoat with epoxy resin or do I have to use polyster resin with polyster gelcoat?

Best regards

Probably. But definitely not recommend. If you got the unimould system anyways, I would stick to the plan and make the whole mould as intended. Why would you substitute cheap polyester with epoxy, which you could use later for the parts you are making?