Plywood hulls in the tropics, real live experiences?

[Dsanduril]

Our previous boat was a WEST system Cross trimaran. We owned her for 40 years, and of those ~15 were spent in the tropics.

No real problems overall, but moisture will help you find the spots that were not adequately sealed with epoxy. Otherwise it's really just keeping the UV away from the epoxy and good ventilation.

One caveat, our boat was mostly mahogany plywood, but some of the deck was Douglas fir. Doug fir tends to check in the tropical sunlight and moisture changes, this causes cracks in the epoxy coating that need to be dealt with quickly, otherwise moisture will get in. I suspect this is a frequent cause of bad reports on plywood boats, especially those built on the west coast of the US where Doug fir is quite common.

[Philipcataproa]

I built a ply epoxy boat with no exterior glassfibre, only sealed with epoxy with automotive two pack paint. The expansion of the wood and the slow srinking of the epoxy opened some cracks in the finish. I cleaned of all paint nad laid down a layer of glass using epoxy then repainted no problem afterwards. After 15 years the boat is like new. Keep the inside well ventilated with ventilators that vallow the boat to ventilate when locked up. Get clove oil from pharmacy and dilute 1.5 ml to liter of water, shake up and spray all mouldy areas end of problem.

[FAST FRED]

"The topsides above the cedar/epoxy is a high grade marine plywood, some kind of mahogany, and has had no problems."

This is the key!

There are many grades of ply and the material its made from is the mist important.

African Mahogany ply is excellent , worth the hassle to import it from England , or where you can source it. Thames Ply