Can you use regular plywood on a boat if you seal it?

Question

Can you use a regular plywood on a boat if you are going to seal it well with something like a truck bed roll on liner?

Answer 1

You really should use a marine varnish.  Apply 3 good coats and let them dry adequately between re-applying.

Answer 2

You should use marine grade, because the glue won't dissolve when water is present. You can use standard plywood, but just a sealer won't last very long. You at least should encapsulate the wood in fiberglass resin. Even that can flake off unless you do it right (fiberglass cloth and all). I did that with GREAT success. It also made the wood much stronger than original. Be careful what resin you use. There are some(finish resin) that contain wax that comes to the surface when cured. If additional coats are needed you will have a problem with the glass and resin adhering to the cured wax coat. You can still use it if you put all of your layers in place before the final curring takes effect (a 1 step process to work). In the end the marine grade may be cheaper anyway, but the glassed in wood will outlast anything else you can do. One other thing is that if it stays exposed to sunlight you will need to add UV protection additive to keep it from deteriorating. Sounds like a good project. Good Luck!

Answer 3

Yes, you can. However, the glue in regular plywood is not waterproof, and if water ever gets to the wood, you will not have a boat any longer. The water can come from the outside or the inside, so you have to encapsulate the plywood TOTALLY.

Regards,

Dan

Answer 4

The key to your question is: seal it well.

I typically recommend marine grade plywood because of the constant exposure to moisture. But if you feel you can get it sealed against that moisture put it in.

Be ready to replace that floor again in a few years if it isn't sealed.

Answer 5

Use exterior grade ply. It is made with the same glues as marine, and aircraft.

The difference is in the core wood (higher strength, lighter weight for boats and airplanes), and surface finish.

Any of the plywood grades will need to be sealed, and maintained periodically.