As a reference check http://store.yahoo.com/hardwoodint/34twinbirmar.html.
The average cost of marine plywood is between $45.00 to $75.00 for a 4'X8' X
3/4" thick.
A decent marine plywood should pass the British Standard for boiling test.
Yes you have to saturate both the cut edges and top/bottom of new floor
boards?
The epoxy we have used was formulated by West System. Any decent epoxy sold
by East, West, Raka or their equivalent should do a good job.
As for the procurement of the material you should googled the Internet and
find out what is available in your area.
More and more boat builders are using a polymer composite material named
StarBoard for hatch doors, Check
http://www.jamestowndistributors.com...King.Starboard
This new polymer panel may cost more but its maintenance free and requires
little preparation compare to plywood and teak.



wrote in message
ups.com...
For marine-grade plywood, should I go to a lumberyard or a boating
store (we have Boaters World and West Marine nearby)? I guess I would
get the same thickness as the current boards. Is there a special type
of epoxy to use? I presume that you mean to saturate both the cut
edges and top/bottom of new floor boards? This sounds like a lot of
work if I then have to varnish too, but maybe it will be worth it if
they last a few years. I would like to get another 4 years or so out
of the dinghy. The only other problems we have with it is that the
finish has become "chalky".