Marine Grade plywood

[North Beach]

Re: Marine Grade plywood

marine ply is no more water proof than any other ply
pt wont rot but many precations need to be taken if used- like it rots alumianam and glass dosnt stick well to it
I used arauca in my boat but now im getting close to being done
I wish I would have just saved the mony and gone with plain extior grade ply

So you're making that statement based upon what? The fact that your cheaper plywood has held up almost until you're done installing it? Jeez!

The glues in the marine ply are waterproof-not water repellant as in all the others. Not to mention it's made of Douglas Fir making it way less susceptible to rot and has less voids than the others.

If you want to use a cheaper product just say you opted for a cheaper product and be done with it.

 

[CaptainKickback]

Re: Marine Grade plywood

Arauco is good stuff IF you can still get it. The Plant burned down and in Okie land it is in Short supply.

Well, that explains that (couldn't find it for my project). lol

Anyway, it seems most iboaters stay away from marine grade ply if they are going to cover it with poly resin and fiberglass or with epoxy. The theory is all the moisture inside the ply is trapped inside. Often cited is that screws (even ss) driven into it corrode in a short period of time. Some people buy their ply and let it sit for several months to dry out. Point being, you want ply with waterproof glue and minimal moisture.

Sea ya...

 

[jasoutside]

Re: Marine Grade plywood

My local Menards has giant stacks of Arauco on hand. Half the price of MG and every bit as nice to work with. Now, it's not Doug Fir so, all sealed up with epoxy it'll only last half of forever.

What was half of forever? I lost my pocket calculator again

 

[Woodonglass]

Re: Marine Grade plywood

This is my point as well ^^^ I really believe that we ALL put WAY to much emphasis on this Marine Grade, Douglas Fir, Pine stuff. I been working wood for 40 years and totally understand the argument. BUT... We are talking BOATS not Permanent Dwellings!!! If this was a house then... OK but. I'm pretty sure that a boat restored with Arauco 7 ply PINE laminate plywood, encapsulated in Semiporous Polyester Resin (Not Epooxy) and Painted (Not Gelcoated) and maintained with some semblance of resonable sanity, will usually last as long as the owner wants to use the boat and probably as long as the next owner want to use it. From what I have seen of factory workmanship, the quality that goes into the Backyard Restorations is such that we are good to go using the materials being recommended. If you want to Pay the extra for the added benefits then that is your decision. I just don't see the reasoning. My 2?

 

[ezmobee]

Re: Marine Grade plywood

Some people seem to be thinking that Arauco is a brand of marine ply. Incorrect. Arauco is a quality alternative to marine ply. However, that's probably a mute point as I don't think they're gonna get that factory rebuilt any time soon.

Marine ply is a quality product but what's considered "marine" does vary by product. It can mean more plys, better glue, some diagonal plys, some products are even treated. Definitely confusing.

I will say that I used standard exterior ply from Home Depot for my deck and the stuff was JUNK. Tons of voids. I used the Arauco for my transom and it was extremely nice.

 

[Struc]

Re: Marine Grade plywood

I will say that I used standard exterior ply from Home Depot for my deck and the stuff was JUNK. Tons of voids. I used the Arauco for my transom and it was extremely nice.

You have to remember there are different grades of exterior ply. The big home stores usually carry them all. If you grabbed some CDX Exterior Ply, it could be full of voids and not very good for decking. BCX would be better, but still will not be as nice as the ACX Arauco panels.

EDIT: The plywood I mentioned in Post #12, which I'm using to rebuild my seats, doghouse, and a couple other things is BCX plywood. It has a nice sanded and filled surface on one side, and the back side has some voids, etc. For the application I was using it for, and the fact that I'm sealing it with Epoxy (seats) or Poly & Fiberglass (doghouse), and it will be covered up on all sides by something, it was a reasonable choice - and one that I am comfortable with. Others may not be. To each his own.

http://menards.com/main/building-ma...plywood/5-8-x-4-x-8-bcx-plywood/p-1455690.htm

When I rebuild my seat boxes, it will be made out of Arauco ACX ply.

http://menards.com/main/building-ma...-x-8-premium-acx-plywood/p-1508796-c-5698.htm

 

[Yacht Dr.]

Re: Marine Grade plywood

I am going to wrap the wood in carpet, will the marine grade be worth the price??

DP .. you still there ? ..

Are you planning on Glassing the wood or just coating it with resin ( and what resin if so ).

Here is the deal with wood and glass ( I dont even know how many times I have said this in the forum ) .. you NEED to prep the wood to accept the glass.

Better quality ply takes less resin to accomplish this.

So you can spend more $ on your wood... or you can spend less on wood and more on resin and headache.

I personally like the added benefit of using MG ply. You use less resin to prep and you have a better quality of ply.

Sure you can use CDX or AC or whatnot .. but you still have to apply coatings of resin to make it ready to be able to handle Fiberglass lams over top of it.

If you dont prep your ply correctly..you WILL get air voids in the lam process ( you think MG is expensive..what about your resins ) .. Not to mention that you will pull out your hair and cuss like a drunken sailor when trying to wet out your glass over it and for some reason you cant get rid of All of those little Air voids that pop up Everywhere. ( or see its all well .. but come back to find that 50% of the lam is already delammed ).

MG is more expensive sure I will give you that. I know you guys are trying to save money because your not Reselling the materials I will agree ..But for sure you dont want to trip over a quarter to save a dime. Im trying to tell you to pick up the quarter and forget the dime.

It boils down to how much time and materials do you want to have your ply Prepped !

MG is the best .. cost wise and time wise..( or very close to cost wise if you have the time and extra materials ).

YD.

 

[NathanL]

Re: Marine Grade plywood

marine ply is no more water proof than any other ply
pt wont rot but many precations need to be taken if used- like it rots alumianam and glass dosnt stick well to it
I used arauca in my boat but now im getting close to being done
I wish I would have just saved the mony and gone with plain extior grade ply

Not exaclty true. If you buy a quality marine plywood that is Lloyds of London stamped and certified it will not delaminate in a boil test - try that with AC exterior plywood you get down at the hardware store.

You can literally slap the word "marine plywood" on anything nowdays. Marine ply made in the US out of douglas fir is a good example. It's no different than exterior construction plywood except for the way the faces are graded and a reduction (not a total lack of) voids in the veneer plys. There is no standard in the US for marine plywood and the old world standard of BS1088 (British standard 1088 and BS 6566) don't really ahve any meaning anymore since the standard elapsed and there is no "standard" any longer or inspection. The only real standard or guarantee of quality any longer is Lloyds of London certified marine plywood that is stamped right on the plywood that it's certified.

When you start talking about quality marine ply like Joubert Okoume (made in France) and such then there is a huge difference in voids, ply quantity, face grading AND the glue used.

As far as quality marine plywood goes the US is pretty far down on the totem pole compared to a lot of other areas of the world like France and Indonesia (Hydrotek and Aquatek which is meranti marine plywood made to different standards). Everyone jumps on the non imported is the best quality bandwagon but that is not always true.

I'm not saying Douglas Fir marine ply isn't what you need, just stating some facts about the marine plywood market today. DF plywood might be exactly what you need....but the phrase "marine plywood" used by itself has almost no meaning nowdays and no way to know what standard that it was produced to. At least regular plywood is made and stamped with an APA stamp, not so for marine plywood.

 

[cbreeze245]

Re: Marine Grade plywood

Anyone bother to check out the stuff made by Roseburg? This is the brand most commonly available in my area. The specs are posted out there but not being well versed in wood working, is all Greek to me. Just wondering how it might compare.

http://bluelinxco.com/Portals/0/Roseburg Product Catalog.pdf

cbreeze

 

[fishrdan]

Re: Marine Grade plywood

Marine ply made in the US out of douglas fir is a good example. It's no different than exterior construction plywood except for the way the faces are graded and a reduction (not a total lack of) voids in the veneer plys.

A big difference with doug fir marine ply is the plys are laid at 45* angles instead of the 90* as in normal plywood. Though, I do agree the name "marine plywood" is a very loose term here in the US as it can be anything from high end expensive okuome to cheap CCA treated plywood that resembles CDX in construction. The doug fir marine ply we normally refer to here as "marine plywood" is some where in the middle. The doug fir marine ply I used in my rebuild had some voids....


For the OP, exactly how are you going to construct the front deck? If you are just going to slap down some cheap outdoor carpet from the big box stores with the intentions of it lasting 3-5 years, I'd just use ACX or BCX plywood (1/2" 5 ply?), several coats of spar urethane and glue down the carpet. When the carpet is fried, just throw away the whole mess and build another one. If you are going to use quality marine carpet and expect 10+ years out of the deck,, use better plywood and coatings