[QUOTE=Rokeby;152783]Aerohead, other readers,
I'd like to share some of my expertise as a boat builder in payback for the
aero knowledge you share with us every day. (BTW, many thanks.)
There is no way to permanently stabilize the surface of fir plywood. No
matter what you put over it, even a layer of epoxy impregnated fiberglass,
in time it will "surface check." That means the face ply will crack and pull
apart, up to 1/8 inch. It will tear the fiberglass. You can put on multiple
layers of 'glass, but the cost and weight get prohibitive. "
There are ways to defeat epoxy encapsulation, but it isn't easy if you work indoors and follow the instructions. Fir ply is seldom bright finished, but it has always worked for me.