Please correct me if I am wrong, but I have read that you should not use epoxy when using fiberglass Mat.
If im wrong on this just take me out and shoot me!
Im pretty sure epoxy and glass fibre go together like ham n eggs.
I was informed recently that polyester resin can be used as a cheaper alternative to epoxy BUT it contracts, does not grip the wood as well and (i think) ages.
See, im learning all the time