On Jul 2, 12:27*am, "SteveB" wrote:
I live in a dry area. *I want to replace some wood on my boat. *Is marine
plywood an absolute necessity, or would a good grade of sanded one side
suffice? *About the only time it would get wet would be when it is outside
and it rains, and we get less than two inches annually.

Steve

Marine grade plywood typically has the voids filled as each layer is
added. You see the void filler on normal plywood only on the outside
layers. When I replaced my floor I selected a plywood that was not
pine rather than focusing on marine grade. Right or wrong, I left the
underside unsealed so that it could dry when it got wet. I also
removed the foam and did not refill with foam. The foam traps the
water against the floor. I added drain holes through the stringers.
I boat in SE inland lakes so the flotation is not much of an issue for
me. I have heard as alternatives to the foam, the use of 1 liter soda
bottles with the caps on them as well as cut up sections of those kids
noodles.