RE: Sun Ray biplane
I salvaged the fuselage side! Luckily the epoxy dried hard (not rubbery) and was easily sanded. I began sanding with a little dremel sanding band and then block sanded.
After fixing the problem I have glued the doublers with some different epoxy. This time I used 20 minute finish cure epoxy. It's old too but seems to be okay. If anything it dries a little slow.
On with the build!