Marine grade plywood?

Anyone know where I can get marine grade plywood?
Need one piece 3/4" 4X8 sheet.
Thanks in advance.

I got mine at TH Rogers in McAlester when I redid part of our boat dock. I think I paid about $90 per sheet and that was maybe 2 years ago. I had to have them order it -- not a normally stocked item. But they had it there in about 2 days.

Fox Lumber here in OKC.

My ladder for the boat came today. I have been trying to decide if I need (or want) marine grade plywood or good high quality treated plywood for the carpeted platform. The boat is garaged so never out in the elements long. I'm also think of using gray Starboard and leaving it uncarpeted. Maybe Reaper can chip in with his thoughts on what would be best. Here's a photo of a similar platform with ladder mounted.

Attachment 182215

IkenI
you don't want to use regular treated plywood if there is any chance of contact with aluminum as it corrodes the aluminum.

OB & Ikeni. One note, I have access to a cnc router if you need it. Think perfectly flowing curves or high precision accuracy.

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Originally Posted by dinobot

IkenI
you don't want to use regular treated plywood if there is any chance of contact with aluminum as it corrodes the aluminum.

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Thanks for the info, dinobot! I probably should know that, but didn't. That makes me lean, more and more, towards Starboard. It costs more but by the time I buy marine grade plywood and carpet, it's probably a wash.

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Originally Posted by Redge

OB & Ikeni. One note, I have access to a cnc router if you need it. Think perfectly flowing curves or high precision accuracy.

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Redge, I think that's over my head. I'm just an old infantry recon guy and know squat about that stuff. Luckily, I have a friend who has a huge workshop and could most likely build the platform and mount it on the boat in a couple hours. There is a small wedge needed so I'll talk to him.

Thanks, guys!

You'd be fine with an exterior grade plywood treated with some type of spar urethane. Then the plywood can touch aluminum. Whatever you do, don't use interior plywood. The price difference between a good exterior and marine is minimal. I want to say $10 or so. Whatever way you go be sure to coat it up good with spar urethane.

Sintra is a PVC Foam board that is lighter than plywood, is waterproof, is UV stable. I've used it for seats, seat backs and various covers, to date none have failed so it may be something worth investigating

Thanks everyone for your inputs, great stuff!
I found a store in Ardmore that ordered me a sheet of marine grade plywood yesterday and should have it tomorrow latest Cost was
$88 total so I'm a happy camper!
Turns out its not as bad a job as I had expected!
Floyd, did you build the platform the ladder attaches to? Looks like a factory install!

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Originally Posted by IkenI

My ladder for the boat came today. I have been trying to decide if I need (or want) marine grade plywood or good high quality treated plywood for the carpeted platform. The boat is garaged so never out in the elements long. I'm also think of using gray Starboard and leaving it uncarpeted. Maybe Reaper can chip in with his thoughts on what would be best. Here's a photo of a similar platform with ladder mounted.

Attachment 182215

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They say that a wise man learns from his mistakes. When I rebuilt the USSPOS, my research let me know that treated plywood would corrode the aluminum. Instead of using Marine plywood, I chose to use a cheaper B/C grade and treated it with Thompsons water sealer. When I lived in Oologah, I could keep the boat garaged and never had a problem. When I moved to Talala Creek, the shop filled up fast and I didn't have the space to keep the boat inside. In less than 6 months, the carpet glue started giving up it's bond. I blame it on the Thomsons.

I'm fairly certain Floyd that if you use regular plywood and coat it with a good exterior primer that you'll have enough protection since you keep it garaged. Sealers like Thomsons just don't allow an exterior carpet glue to properly bond to the plywood.

I came across a Ranger 373v recently that may need extensive work to restore. I might try to do some horsetrading with the guy that has it. He doesn't know he's getting rid of it yet.

They actually have a marine grade urethane which is what I would recommend. It's more expensive but what should be used. That and the exterior or marine grade plywood.

Sorry Floyd, didn't read close enough and realize you don't have the ladder mounted yet. Would appreciate a pic or info on what you decide to do.
Dr Nip, can you share more info on the proper adhesive to use on marine grade plywood? Would be a big help.

The difference between marine grade and exterior grade is marine grade is void free in the inner plies. They both use the same type of glue. Where alot of people go wrong is using pressure treated wood and putting it in contact with aluminium. That is a no no and is what Reaper was referring too. You'll also have problems getting products to adhere to it, i.e. sealer and then adhesive.

As stated use a marine grade spar urethane to properly seal it.

https://www.google.com/webhp?sourcei...tbm=shop&spd=0

When using an adhesive make sure it is marine grade as well.

Do it properly and you shouldn't have any problems. No need paying a premium for marine plywood and then skimping on the protection and adhesive.

IkenI, that's a nice looking ladder. Who makes it?

I got it at Overton's. I think they make it - called a Dockmate on the box. It comes in 2, 3or 4 step and is rated for 400 lbs. Mine is a 3 step like the one in the photo.

Telescoping Drop Ladder 2-Step - Overton's

Thanks IkenI, I fish by myself a lot in the winter and have been thinking I should put a ladder on boat but have not found one I liked.