Marine Grade Lumber
 

I'm rebuilding my engine hatch, and need a sheet of 3/4 inch plywood, and a 2X4. Where can I buy marine grade lumber? Do Lowes or Home Depot carry something like that? Is pressure treated good enough.

I would definetly stick with the Marine Grade. Your local home improvement stores don't usually carry this. You need to seek out one of the more specialized lumber yards. You know the lumbar yards that were around prior to the big stores moving in. Their lumber is often better anyhow. I don't know what you have down there but shop around, they do still exist.

Marine grade is very expensive. What I did was use a good outdoor plywood and encapsulate it in resin. This will seal it forever and last forever. It might be tough to get staples through but it can be done. Did you check on Starboard or the other "plastic" brand boards? This is also very expensive but if you have a small area it won't be so bad. I would encapsulate the marine stuff also if you go that route.

I like the encapsulation idea, that would pretty much eliminate this ever happening again. How much weight would that add to the hatch?

FYI; I just bought a sheet of 3/4" 4x8 for $80.00 at our local lumbar yard. If your lumbar yard is close to a waterway they usually will have it.

Good Luck.

Wow! $80 bucks for a piece of plywood.

The only difference btwn. marine grade wood and regular plywood is that the marine grade is guaranteed to have no voids. The glue and the wood is the same. If you use preasure treated wood or plywood you can not put resin on it. Not only will it not stick but the preasure treated woods always release gas and that can not be sealed in. If you use marine grade or even regular wood and you intend to seal it up then you can use Thompsons water sealer, or resin. If you use resin thin it out big time or you will not be able to staple into it. Thinning it out also allows it to sink in deaper. Good luck

Jon

The diffrence between marine grade and exterior ply wood is the voids, do not use an interior grade the glue is not waterproof also try and get a fir face on both sides.
As far as resin you should thin it with styrine (sp) it will also help penitrate the wood but I would put in at least 1 layer of glass resin allways seams to peal off without any glass in it.
most of this information I got while redoing the floor and transom of a gaywhiner (lots of rot) got my best info. from the fiberglass shop, good luck.

80 bucks, are you crazy !!! use treated lumber, after you cut the wood to the size you want just paint it with a poly sealer.

I'm reading a book on fiberglass boat building. They said that you can encapsilate exterior grade plywood and be okay. Eggbeater said it that marine grade doesnt have any voids. This book confirms that. And resin will not stick to treated very well.

Also when using dimensional lumber fir is best, oak, maple, or any hardwoods are not good. The resin will not adhere to the hardwoods because of the oils in the wood.