Originally Posted by
Sixty Fiver
I have clear coated older frames to preserve them once any rust issues have been addressed... have used clear shellac which provides an excellent moisture barrier and gives a very smooth finish.
PLUS ONE
Shellac is about 7 times more moisture-impermeable than epoxy, and about 3 times better than your medium enamel paint.
Still and all, once the tinworm really takes hold, there's not a lot of easy fix to the problem. In the long run, you're probably going to have to bite the bullet and do a recoat.