marine plywood for new deck

[littlepoopers]

I've been all over Google trying to find 5'X10"X1/2" marine plywood. Everyone I've talked to says I can't buy just one sheet, but that's all I need to do the job. Can anyone help me find one sheet? I'm willing to drive several hundred miles to pick it up as shipping would be over $150.00. I live in Lima, Ohio. Thanks for any advice you can give.

 

[Scott Danforth]

buy exterior grade arauco plywood from your local lumber store.

 

[Woodonglass]

Why the need for 5' x 10' sheet??

 

[Grub54891]

Our lumber yard don't stock it, but I call them nd order it, it's there within 2 days.Not sure about a 10 footer though.

 

[littlepoopers]

I'd like to be able to do the job without any seams. I might have to bite the bullet and buy two 4'X8' pieces.

 

[littlepoopers]

Buy the way what is the best glue to use for a butted joint?

 

[Grub54891]

Several years ago I tried to get a piece 5foot by 15 foot mahogany for restoring a wood boat. I contacted 3 different plywood mfg, one called me and said nobody makes it like that. Bummer, had to do the seams. In my case I was able to hide them in the construction.

 

[KD4UPL]

If you're really willing to drive a long way try Mongers in Harrsionburg, VA. That's where I bought some marine plywood years ago. I didn't need a 5 x 10 however.

 

[jbcurt00]

Harbor Sales might have it
http://www.harborsales.net/products/wood.aspx

But lets start w what are you working on?

Butt joints on the deck of a boat, likely doesnt need to be glued. Fiberglass'd over, yep, if its a glass boat.

 

[littlepoopers]

I'm sorry, I didn't say what boat I have, its a 16 ft. Starcraft the deck is really rotten and I'm in the process of tearing it out now. Just an aluminum boat from the 70's. I'll probably have to buy two 4X8 boards and seam them together.

 

[jbcurt00]

What SC 16ftr, do you know what model?

Lots of 16ft Starcraft tin boats have been done, none used 5X10 ply, and nearly all didnt glue the butt seams between the 4X8 sheet pieces. And I can think of only 1 that used fiberglass tape and epoxy to simply cover the seams.

 

[Woodonglass]

Yeah, absolutely NO reason for a one piece seamless deck and use of Marine Grade plywood. A good grade of Ext. Plywood (Like the Arauco Brand mentioned) and then sealing the plywood with either epoxy or a good wood sealer will yield a deck that will last for many many years. Save your money for use elsewhere..
For your joints you use cleats and if you want you can use thickened resin to seal the joint. As stated if you decide to Glass the seams it will provide even more protection and sealing.

 

[PTChief]

If the seams are your sticking point...I'd say you have a couple of options depending on what you have for tools. You can prepare the butt joint, and then use a router with a parting bit to cut a spline channel in both pieces. Lay them together with some glue and you'll have a pretty much clean seam, other than the grain change. You can also use a biscuit cutter to provide some strength with biscuits. I agree with the others that "marine plywood" isn't really necessary for the floor. Find the best exterior plywood you can locally. More plys will yield a better joint and floor. depending on your sources, you might consider aluminum composite panels. They do come that large and in my opinion, are a better alternative to plywood. Commercial contractors and signage types would have a source.

 

[littlepoopers]

Great ideas fellas, you have put my mind at ease. Thanks for the help.

 

[slimdaddy45]

I do believe if you have a Menards close you can order it there check out their website they stock marine plywood in 4x 8 but I think you can order the bigger sheets but I may be wrong on the marine but you can other plywood

 

[Drb007]

My local Menards has the marine grade 1/2" 4x8 on the shelf. They had the 5/8" 4x8 in 2 days.
I didn't ask about the 4x10 sheets. I don't think the seam is a bid deal. You could scab a 1x4 under the edge of the first piece, 2 inches under the edge so you have a 2 inch ledge for the second one screw into. I use epoxy, so I would epoxy everything well. It won't be a weak spot.
I know others feel the marine plywood is overkill, but to me, the cost was less then $10 per sheet difference. For a total of $40 more on my entire project (I am already in $800 just for epoxy!!!) why not get the best stuff you can?

Now, if it was a $400 difference, I can see using exterior plywood. But that isn't the case. I would pay $40 for piece of mind, even if it does make me seem silly to those here who are smarter than me

 

[jbcurt00]

You dont need a 4in scab under a plywood seam, a strip 2in wide, well sealed piece of plywood scrap would be plenty. 1in beneath each side is enough.

Oh, and a 1X4 is only 3/4 X 3.5in

 

[JASinIL2006]

Personally, I prefer to scab with a piece of plywood rather than the piece of dimensional wood. Less chance of plywood splitting along the grain than dimensional wood.

 

[Woodonglass]

Personally, I agree with using plywood for the cleat and I also agree with 1x4 You need to ensure you have enuf to screw into without splitting the material. Make sure to pre-drill and fill with resin and precoat screws.

 

[PTChief]

As an update, I was able to purchase some aluminum composite panel from a guy outside of Boston. 3/16's thick. 5x15 sheet for cheap money. This will be my new floor. A bit lighter, maybe 10-20%, than 1/2 marine ply but a lot stiffer and certainly rot proof. The guy I bought it from got it from a commercial building project that was finished. The real positive is anywhere I want access or a hatch, I can just cut it out of the composite and use the cut for the hatch. Rivet a little straight aluminum stock underside and put some carpet over it. It's nice stuff to work with too...cuts with regular carbide tools.