On Oct 27, 11:35 am, salmobytes wrote:
..........and even then I was talking about hulls
made with plywood that is skinned on *both* sides
with fiberglass. Hull that have fiberglass on the outside
and a paint or oil finish inside can more easily dry out.

I've seen driftboats--with 'encapsulated' epoxy fiberglass bottoms--so
saturated with water their weight was almost double. If you do
build that way you have to keep up with the repairs, adn patch
dinged fiberglass almost right away (not all that hard to do,
but you must do it).

Or you can build with honeycomb core. It's bullet proof and fool
proof,
almost. You can pre-fiberglass honeycomb core while it's still
flat, on top of visqueen covered saw horses, and then treat it
like plywood.

The encapsulation is the problem. Once water gets in, and it will, it
can't get out. The best way to handle plywood in my opinion is with
paint which is more easily repaired, and allows for some breathing. I
have some plywood boats over a decade old that are fine. One in
particular, a Payson Skimmer has a glass sheathing on the bottom, but
the inside of the ply is paint. I know that about a hundred folks will
come in and slam me here, like every other time I say eposy is not
waterproof in practice, even if it is in theory so I will not argue. I
have built over 60 plywood boats in my life...