Can anybody help with some advice please?

I am about to glue new decks on my boat, but I was wondering how to waterproof the undersides on the deck. (I have a high tank, so access is limited). If I give the underside a couple of coats of epoxy, is it flexible enough to be bent over the frames without cracking or should I use an alternative method?

Thanks for any help

Use epoxy paint it on and then lay deck whilst its wet it will be the glue too.

I have heard advice to epoxy the panels of a mirror kit before assembly so it better not crack when bent!

It'll bend on just fine when epoxied, suggest roll on coat then do a final dry fit, then when perfect fit roll on second coat and then using same epoxy 'bulked' up with micro fibres/silica clamp it down. I'd use slow hardener which obviously would give you a longer work time. Have fun Barry.