[VAC] Re: painting plywood

["Tom" <tmeeker@xxxxxxxxxxxxxxx>]

Shellac is a great sealer for marine grade plywood.  Make sure you use at
least Marine Grade plywood as that is what was originally used in my 1969
model anyway.

I took our old carpets up, sanded the floor nicely and applied a nice couple
of coats of shellac, allowing drying time between coats of course.

I see nothing wrong with sealing the underside of the wood as it's already
treated for moisture, your call.

But, I would NOT just prime it and let it go as primer may have the ability
to hold water even on the bottom side due to surface friction.  You would be
better off to either leave the bottom side alone or seal it with Shellac.
Shellac won't hold moisture but it will seal the pores which will stop it
from absorbing moisture.

Tom