Plywood revisited

[RunninLund]

Big thanks to iboats and this community for being here. I just started a restoration project on my 1984 Lund. I am building decks for the front and re-running wires etc. The problem I'm running into is with the plywood for the decking. I've read a ton on this site and others. My problem has been with matching the available plywood at Home Depot etc. with the plywood recommended by people on this site. Basically all outdoor plywood at Home Depot is full of voids and basically looks like crap. The only decent looking plywood they have is indoor plywood that comes in sanded or non-sanded. My buddy suggest to use the indoor with several coats of polyurethane on it. From what I've read this is a no-no. What do you guys suggest?

 

[csasdaddy@msn.com]

Best to find some marine grade plywood or use a man made material like croosa board or something similar

 

[DeepBlue2010]

You buddy is wrong. Interior plywood is not glued with water resistant or proof glue. Which is understandable since it is intended for interior use.

You need to get someone in HD to get off their lazy behind and do their job and order it for you or you need to look for another supplier or lumber yard.

Where are you located?

 

[RunninLund]

I'm near Vail, CO. Not much for selection up in the mtns.

 

[DeepBlue2010]

Try ordering from Home Depot Web site delivered directly to your home or to your local store. Home Depot can do it either way.

 

[csasdaddy@msn.com]

Check around lake areas an near the coast may have to travel to get some . I know I do well to get at a reasonable price anyways I have to go 300 miles

 

[gm280]

:welcome: RunninLund to iboat. Nice to have you join us...

Not being familiar with your boat project or how you are refurbishing it, I have a few questions. Are you using the plywood only as the platform or going to paint or carpet it? If you are going to carpet it, you can use most any type EXTERIOR plywood even with voids. And any void on the surface can easily be filled in with PB (peanut butter mixture of Polyester Resin, Cabisol, MEKP, and even Chopped 1/4" fiberglass strands) mixed up to form a great filler putty. Then follow that with a CSM and poly coating and carpet. It will last for a very long time and be really solid. Don't use interior plywood regardless how nice the finishes look. It will delaminate before you know it. I am sure you only want to do this one time. So go the extra effort to get the correct materials to do this job. You will thanks yourself in the long run. JMHO!

 

[Starcraft5834]

marine plywood, or synthetic material that wont rot.... regular ply and poly?? NO!! Poly is no intended for outdoor applications.

 

[tpenfield]

Lowes (if you have one near you) might be a better source for plywood, if you cannot find what you need at HD.

you want "Exterior" grade (APA rated Exterior) "Marine" would be even better, but "Exterior" will be fine and many boat manufacturers use that type of plywood.

Interior will last about 3 months . . .

The ratings of the outdoor plywood generally are:

Exposure 1
Exterior
Marine

They all use the same waterproof glue, their differences are in the quality of the wood. "Exterior" with one side good should be fine for your use. I would also coat it with resin as you are re-building to prevent water absorption.

 

[Woodonglass]

Yup ^^^ any wood used must be coated with something to preserve it.Even Marine plywood will rot if exposed to water for a period of time.

 

[Ned L]

lol, .......... I'm going to sit this one out.

 

[Scott Danforth]

If you have a lowes, you may have a better chance of finding decent exterior ply. If you have a real lumber yard vs a big box store lumber yard, you will have a better chance as well.

 

[harleyman1975]

Yes Ned not much use for plywood on those lap strake boats is there?

 

[Ned L]

Yes Ned not much use for plywood on those lap strake boats is there?

Quite true! lol (Though there is some plywood in her.)

 

[RunninLund]

Thank you all for the responses!
Yes, I'll be carpeting it all. The best I'm going to be able do is CDX, I guess. I'll try going through the stack and see if any are better with voids than others. Two and a half hours away they sell marine ply for....$185/sheet.:faint2: That's out of the question...

So, any suggestions on coating and glue that they sell at HD? Maybe Lowes?

I very much appreciate all your input! It definitely helps the thought and calibration process!

 

[Ned L]

There are a lot of options for sealing it. In my opinion,... A couple of coats of Rustolem ($10 / QT) will get you pretty well there with sealing it. Sure, there are other things that can be done (with more cost), such as epoxy coating it. "WOG" has a mixed recipe that of a couple of readily available ingredients that has good faverability with a reasonable cost.

 

[redneck joe]

Thank you all for the responses!
Yes, I'll be carpeting it all. The best I'm going to be able do is CDX, I guess. I'll try going through the stack and see if any are better with voids than others. Two and a half hours away they sell marine ply for....$185/sheet.:faint2: That's out of the question...

So, any suggestions on coating and glue that they sell at HD? Maybe Lowes?

I very much appreciate all your input! It definitely helps the thought and calibration process!

penny wise, pound foolish...


your call. Either way make sure you are putting into your truck what you think you are. My new floor has rot after a year and I followed all these folks instructions. Only thing I can think is I pulled from the wrong slot.

 

[csasdaddy@msn.com]

Thank you all for the responses!
Yes, I'll be carpeting it all. The best I'm going to be able do is CDX, I guess. I'll try going through the stack and see if any are better with voids than others. Two and a half hours away they sell marine ply for....$185/sheet.:faint2: That's out of the question...

So, any suggestions on coating and glue that they sell at HD? Maybe Lowes?

I very much appreciate all your input! It definitely helps the thought and calibration process!

My local Lowe's said they could get it for 80+ a sheet but unless I bought 500$ worth There would be a charge of 75 to get it from manufacturer supposedly

 

[Ned L]

penny wise, pound foolish...


your call. Either way make sure you are putting into your truck what you think you are. My new floor has rot after a year and I followed all these folks instructions. Only thing I can think is I pulled from the wrong slot.

Hmmm,.... I would be interested in exactly what type of plywood you used, what you coated it or sealed it with, and how it was installed in the boat. You can just about take a sheet of CDX and toss it out in the dirt and it will still be solid a year later.

I have used everything from $175 a sheet 3/4" Okume, to $29 a sheet 1/4" ACX and understand that more expensive doesn't always mean 'better'. Quite frankly the $29 ACX may well be 'more rot resistant' than the $175 Okume.


Sorry to hear about that. It certainly is disheartening to put in that effort and work, and have that happen.

 

[sheboyganjohn]

If you are doing light weight stich and glue boats, then by all means go with marine ply. If you are building a hull go with marine ply or another void free high number of ply plywood. If you are doing the deck, use regular exterior plywood, or a better grade of plywood with exterior glue. Menards has some decent ACX plywood. I have also used BCX for decks. Marine grade has nothing to do with rot resistance, it has to do with how structurally sound the plywood is. Any wood you put in a boat either needs a barrier coat of some sort, or needs to be exposed in a way that it can completely dry on both sides when it gets wet.

So for your install where you will carpet it, I would suggest BCX plywood with a layer of CSM and poly resin. If you want to do it on the cheap then at least seal the wood good with some type of sealer. No, resin by itself, weather it is epoxy or poly is not a sealer. I can find every spot on the dory whether the Baltic birch ACX, MDO, or BCX, where I did not have glass with the resin. It has surface checks, MDO more chipping then checks, but no the less, it did not maintain a fully sealed surface. And that boat is all epoxy. At least I can sand over the spots and put a layer of glass down. Work/ hunting grade building allows you to be a bit unfinished.