[RGPGuitars]

Besides making guitars, I build skin on frame boats at the Canadian Canoe Museum in Peterborough On Ca where I live.
The nylon or Dacron skin is sealed/waterproofed with a unique 2 part, non toxic, odourless catalysed polyurethane. It stays flexible and doesn't seem to shrink .
I pore filled a piece of Cocobolo, sanded back to the wood the next day, and applied a coat of true oil that day after. Pores are totally filled .
It sands more easily than epoxy, and not as toxic.
Skinboats.org $15us for 12 oz.
Think I will give it a bigger test on white ash.