I need some advice on repairing an old glass board. The fin box needs replacing as half of it is at the bottom of the ocean with a nice fin. Its been there for over a year. (did i mention i am the worlds best procrastinator).
Upon leaving the board it caused a bit of delamination, which i have routed back towards the rails untill it is still attached to the foam, approx 6" square which will need to be re glassed.
i have also routed out the rest of the fin box but got a bit carried away and one of the two stringers in the board is quite thin.
have also routed slots to take extra stringers either side of the new fin box (these go all the way through to the underside of the top/deck laminate and longer than the fin box.

So after all that, the question is, which will be better epoxy rein /glue or polyester resin (the latter being cheaper and originally used on board)
can the polyester be thickened similar to epoxy.
How long does it take for either to cure and be able to use the board.

thanks in advance for your thoughts and opinions.

ps the board is old but in good condition and goes well at my local in 30+knts
its the multicoloured one in my pics sitting on the stairs.