materials to seal plywood

[capslock118]

Perhaps I'm just missing the boat here, but I am reading a bunch of threads about plywood 'exterior vs. marine grade' and regardless, to seal it.

I don't seem to be picking up what you would use to seal it with though.

I've read one account of using epoxy resin.

I go here and there are different types.

my goal is to reupholster exterior boat seats. I plan to

1. use exterior plywood, maybe even regular plywood if there is a way to really seal it well
2. install new foam
3. wrap in plastic
4. install the vinyl

Is there a specific epoxy resin I am suppose to use and, is it just a matter of lathering it in or are there more steps involved?

thanks.

 

[robert graham]

Re: materials to seal plywood

I've used polyurethane thinned out so it penetrates the wood real well, apply several coats, then it's sealed up good and will probably outlast the rest of the boat. I used this method on the plywood transom of my canoe and it sits out in the weather all the time, the transom is 20+ years old and still solid. Good Luck!

 

[Woodonglass]

Re: materials to seal plywood

Yep Poly will work, however I would recommend using the 10 minute epoxy you can buy at the Home Centers. Use it ONLY on the edges of the plywood that will be on the deck of the boat that could weep up water. Just mix it up and brush on a medium coat. If they are sealed up then the several coats of poly should keep the wood sealed for multiple years to come.

 

[ajgraz]

Re: materials to seal plywood

C'mon, at least use exterior grade. If there's just one pinhole in your sealing job for moisture to get in, the interior grade ply will eventually delaminate.

Epoxy is not UV stable, but since the wood going to be covered and not exposed to sun, that's fine. When I sealed plywood for upholstery, I used two-part epoxy thinned with about 1/3 carb cleaner and just painted it on, faces and all. Or you could use polyurethane varnish as has been suggested. Whichever you can get cheaper. And has been suggested, put three or four coats on the edges! (Another hint, fill any voids in the edges with thickened epoxy/MarineTex type stuff, first)