Marine Plywood or pressure treated???

[apollo18]

What is better for a floor in a jet boat. The wood will get wet over the years and i dont want it to rot. I only want to do the job once. Marine Plywood or pressure treated???

[Ted Stryker]

Kind of a catch 22, you want the wood to be rot resistant, but if the fiberglass work is correct it won't get wet to begin with... High end boat builders can be seen using both, I used to hear about the treated lumber being more difficult to bond laminates to but someone must have figured it out... Treated lumber will be a bit heavier also... If you plan on doing the work yourself and your not a pretty good glassman, I'd recommend the treated lumber... Be sure to ask for some competant opinions on the particulars of bonding to treated wood...

[1BadAction]

glass will not stick correctly to treated lumber. period. Marine ply is treated and then Kiln dried so glass will stick. Get PT lumber and do your hull and you will regret it. PT is junk, mmmK.

if a mainline manufacturer is using PT lumber id like to know who, cause Id run like hell away from riding in one of those hulls.

[Tom Foley]

I have been informed from my fiberglass fabricator and small parts expert that there is a new pressure treated product that is specifically designed for boat builders . I will try to post a product name tomorrow . We were using Penske Composite board for the top of our electronics boxes and now this product is going to be substituted for better screw retention . Check with a plywood specialty supplier for the highest grade of marine plywood available that should also be glassed on the bottom side with a layer of 3/4 OZ matt before cutting to fit in place .

[sho305]

It depends on what you are doing, what type repair and hull. For a performance boat it is not such a good idea to use standard treated. They use pretty cheap lumber for it also. If the boat is not that great and you will not be stressing it much, well people have used it. You have to make sure it is very dry, and new it is very wet as it was pressure cooked in the fluid. No doubt this could contribute to bonding problems. IMO, (and there are lots of them on here, you can search and find plenty of threads on wood types and other cores) I would not bother with it. Treated will rot if soaked in water though it may take a little longer. Still, it will delaminate and come loose from whatever you bonded it to just like plain wood will. Unless you have a special app where it will only get wet once in a while and can dry otherwise (like maybe a hatch cover?), and you are not glassing to seal it (as that will not let it dry if it gets wet). I'd use plain ply of quality the hull needs, and seal it good with whatever resin you are using (seal the pieces all the way around). Find ways to not break that seal and it will last a long time. Maybe put some extra glass in places it will get lots of traffic to tuff it up, and figure out how to mount stuff to it so it stays sealed.

[JW]

Isn't there a couple different composits out there for flooring now? He want's it to never rot again.......................

[sho305]

Composites oh yeah, if you are serious and don't mind the price then use something that will not rot at all.

[apollo18]

it must also provide hull strength. Are there marine studs also (2x4) etc?

[Ted Stryker]

BULLET Boats uses PT wood... There was a comment on marine wood being kiln dried, that is a good idea, but wood needs to be installed shortly after being dried in a low humidity atmosphere... Wood will obtain the moisture of it's surroundings in just hours...