I would seal it to get a final moisture barrier outside the microballoons.
I faired the bottom of Rutu before turning her over and figured I better
seal it up well not only for a moisture barrier but some protection during
the rest of construction. I rolled and tipped three coats of epoxy with
about 60% by weight copper. I could see my face in it.

I will be doing the same to the topsides (without the copper). Then sand to
about 240 before applying the high build primer and 2 part LPU. I tested
that substrate/primer/topcoat combination on my Gerr Nester and that poor
little boat has been sitting upside down by the pond in full sun for 3 years
now and looks as good as the day the paint cured.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

wrote in message
oups.com...
Thanks for the heads up

Missing information:
Stitch and glue plywood construction, epoxy and fiberglass overlays the
wood ( no wood is exposed ), one part polyurethane finish, the area in
question is the entire hull.