I would like to say, that I think that a lot of the problems with
sheathing a hull with poly, have been to do with the preperation and
the way the job was done.
I have had a lot of success ( no failures after 10 years in one case).
The method I always use, is to sand off the hull (plywood) with a 16
or 24 grit sanding disk, on a 100 mm (4") grinder, the rougher the
better. get your glass cut to fit C.S.M. Mix up a coat of resin,with
a "hot mix". and thin, with acetone, enough to make it really runny.
My theory , is that it must be runny enough to penentrate the fibres
of the timber. The acetone, evaporates away, as soon as you brush it
on and leaves the resin as a "primer". When this is just "going off",
start laying up the glass with more resin , but this time without
thinning it.I always use chopped strand mat, and not cloth, I think
you get a better bond.
hoipe this helps, Bob