"Gordon Couger" wrote in message news:yMNpc.31057$bS1.19364@okepread02...
"Brian D" wrote in message
news:y_rpc.54753$xw3.3275430@attbi_s04...
In the book Devlin's Boat Building, Sam Devlin states that boats over 90'
have been built using these methods.

Brian

When I think of Plywood composite boats I think of plywood as the core
material for a fiberglass lay up. Plywood is stronger than most cores and
this strength is probably use in the structure of the boat so it is
important that it remain dry an rot free. Not easy things to do over a long
period of time.

Good thinking: Devlin designs plywood boats glued together with epoxy
and glass. Plywood cored boats with epoxy/glass skins are very
different. It is correct that in small boats, we use the properties of
the core. It is an hybrid material, between plywood and sandwich.
About large ones: once you get to 25-28', a foam core is a better
choice. Lighter, stronger, no risk of rot.
That is why se stop using plywood in that size range.

Jacques from bateau.com