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Has anyone used composite material when replacing the plywood used in decking? For example, in some Whalers plywood was used under the deck for screws mounting seats, etc. above deck. Some used blocks. Depends on year and model. Of course some manufactures used plywood covered with glass for their entire deck. With today's composites would that be a better way to go?
Thanks in advance,
Tommy

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Hi, I'm working on my fwd hatch cover on my outrage as the balsa core rotted and am useing sarboard as the core. So far so good with the results,also used epoxy to hold it all together. I redid the deck above the tank area 2 yrs ago and used marine plywood. Nothing wrong with useing ply, just make sure that you seal up any holes that are made and all edges are sealed as well. Use 3m sealants for the scew holes as you're fastening things down.

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In my opinion, plywood will maintain it's structural integrity (rigidity and ability to hold fasteners) longer than a composite if you subject both of them to long term soaking. That's assuming you're talking about marine plywood versus USB-type sheets - i.e. wood fiber and chips coated with resin and pressed into sheets.

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Some composites do not take well to epoxy's. Fiberglass is porous but materials like starboard are not.

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Tommy, can you be more specific on the core materials you are comparing? Composites has a very broad meaning.

Here is a description from the composites wiki "Composites are engineered materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct on a macroscopic level within the finished structure."

Pywood is considered a composite and even Wood itself is a natural composite of cellulose fibers in a matrix of lignin.

Starboard does not make a good core material, mainly because nothing will bond to it and the skin to core bond is important in a composite (Fiberglass + resin + core = composite).

Here are some commonly used core materials:

End grain Balsa (is still considered the best by many builders)
Structural foam
Honeycombs
plywood

Honeycombs are quite expensive and srtuctural foams are not cheap either. They are good core materials when used properly but not necessarily a good choice for the inexperienced.

Balsa is a good core material with a excellent weight to strength ratio as well as being very rigid. Basla has the best skin to core bond of them all. You would need to add blocks of plywood where you planned on mounting something if you went this route.

Plywood is still the best for everyday use. As long as it's done properly and any holes drilled through the skin are sealed, it will last a long time.