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marine plywood
Posted: Thu Jan 29, 2009 8:37 pm
by fishnboy
Im getting ready to redeck my 28ft pontoon boat when I called some of my local lumber yards and ouch that stuff is high!112 dollars a 4x8 sheet here in chattanooga tn.I seen the site pontoonstuff.com but by the time I paid shipping on it I could by it here in town.I was thinking bout using presser treated plywood bout im scard that it would do like my deck on my house did.when i decked it i put nail size gaps in it and not even a year later the gaps where bout half inch.and I heard thatit would burn my carpet up.ANYBODY HERE HAS USED PRESSER TREATED PLYWOOD ON THERE PONTOON BOAT??What are the long trem effets.would it be a mistake?are would it be better to use just plan old plywood and seal it with tompson water seal?are just bite the bullet and order marine ply.And i have thougt bout advantac osb board.but what would it do?please any advice would be great..
Re: marine plywood
Posted: Thu Jan 29, 2009 10:01 pm
by lakerunner
The problem with treated plywood is they don't make it in anything but C/D grade ( or used to not)
Now that might not be a problem but having used it for some marine applications I would use exterior grade plywood first.If you trailer and have a covered storage for boat the plywood would have time to dry and not stay wet.
Best bet is do it right the first time if your planning on keeping toon. If not planning on keeping it more than a year or two you might get away with using non marine grade.
Re: marine plywood
Posted: Sat Jan 31, 2009 6:27 pm
by shootandfish1
New guy here. I have been trying to learn as much as I can about boating, mainly pontoons and 'jon boats'.
I have read more than a few posts that warned against using pressure-treated wood in contact with aluminum. The chemicals used in treating the wood reacted with aluminum.
Seems like pressure trailer bunk boards covered in carpet was a big no-no. and a lot of guys were decking older jon boats were warned not to use pressure-treated plywood.
If I am full of poop - sorry- Hopefully some of the more knowledgeable guys will chime in.
Fred
Re: marine plywood
Posted: Sun Feb 01, 2009 2:07 am
by lakerunner
shootandfish1 wrote:New guy here. I have been trying to learn as much as I can about boating, mainly pontoons and 'jon boats'.
I have read more than a few posts that warned against using pressure-treated wood in contact with aluminum. The chemicals used in treating the wood reacted with aluminum.
Seems like pressure trailer bunk boards covered in carpet was a big no-no. and a lot of guys were decking older jon boats were warned not to use pressure-treated plywood.
If I am full of poop - sorry- Hopefully some of the more knowledgeable guys will chime in.
Fred
Good point that I forgot about. New treated needs to be kept away form direct contact with aluminum.
Re: marine plywood
Posted: Sun Feb 01, 2009 6:22 am
by leon phelps
I am pretty sure that pressure treated is meant to stop insect infestation and that marine grade is for exposure to elements.
The marine grade uses epoxy glue for the layers so that the plies will not come apart...
Re: marine plywood
Posted: Sun Feb 01, 2009 6:56 am
by badmoonrising
Older pressure treated plywood contained Copper, Chromate, and Arsenic (CCA)and was ok to use for decking, but not in a cabin or sleeping area due to the arsenic. Once arsenic treated pywood was banned, lumber companies switch to a salt based preservative which is horrendous on aluminum.
Go with marine grade, it's worth it.
Re: marine plywood
Posted: Sun Feb 01, 2009 7:48 am
by accent
Pontoonstuff.com sells the CCA treated marine plywood. They have a special price on a redeck kit that includes the wood, carpet, adhesive, screws, seam tape and fence risers. Everything comes on one pallet so you save separate shipping costs. I got their kit and was very pleased. They ship Yellow Freight and call the day before delivery. Took four days to New Jersey. Even with shipping it was less than buying separately and getting marine grade locally.
Unless you fish alot, get the heavier weight carpet. The plushness is worth the little extra.
Re: marine plywood
Posted: Sun Feb 01, 2009 2:23 pm
by shootandfish1
accent wrote:Pontoonstuff.com sells the CCA treated marine plywood. They have a special price on a redeck kit that includes the wood, carpet, adhesive, screws, seam tape and fence risers. Everything comes on one pallet so you save separate shipping costs. I got their kit and was very pleased. They ship Yellow Freight and call the day before delivery. Took four days to New Jersey. Even with shipping it was less than buying separately and getting marine grade locally.
Unless you fish alot, get the heavier weight carpet. The plushness is worth the little extra.
Look at "Pontoonstuff Forums" , under the general ( I think) section there is a short thread on treated marine plywood.
Fred
Re: marine plywood
Posted: Sun Feb 01, 2009 2:23 pm
by shootandfish1
accent wrote:Pontoonstuff.com sells the CCA treated marine plywood. They have a special price on a redeck kit that includes the wood, carpet, adhesive, screws, seam tape and fence risers. Everything comes on one pallet so you save separate shipping costs. I got their kit and was very pleased. They ship Yellow Freight and call the day before delivery. Took four days to New Jersey. Even with shipping it was less than buying separately and getting marine grade locally.
Unless you fish alot, get the heavier weight carpet. The plushness is worth the little extra.
Re: marine plywood
Posted: Sun Feb 01, 2009 3:04 pm
by toondog
i put nail size gaps in it and not even a year later the gaps where bout half inch.
i used the marine grade from pontoon stuff. i think most all wood is going to shrink some. best bet is not to have a gap and use a sealant on the bottom were the boards lay on the aluminum. that will help keep the splash up from soaking through the carpet. IMO, i would not seal between the boards. i would think that after the boards do shrink some, small pockets would form holding water. if you just seal underneath, the water could roll out the sides.

Re: marine plywood
Posted: Tue Feb 03, 2009 3:08 am
by FloterBoter
changed mine to an extruded aluminum deck. no more wood for me.
also went with vinyl flooring. no more carpet stains for me.

Re: marine plywood
Posted: Tue Feb 03, 2009 7:33 pm
by wish2fish
I was at the lumberyard asking questions for my transom project and the guy who sells the lumber to the yard was there and took time to explain some of the differences.
Marine plywood has zero voids and uses waterproof glue. There is no protection against rot so the wood must be protected. $100/sheet
MDO plywood should not have voids and uses waterproof glue. There is no protection against rot so the wood must be protected. He didn't know how the resin paper overlay would hold up to the marine environment on my transom because it sits in the water. $70/sheet
Treated plywood has voids and uses waterproof glue. Voids can cause problems when they hold water. Can create weakness. Treatment protects against rot. $30/sheet
Regular plywood has voids and may or may not use waterproof glue. Voids can cause problems when they hold water. Can create weakness. No protection against rot. $35/sheet
He said they have another product that is from south america. I didn't get the name but he said it is the quality of marine but is not marine rated here. No voids, waterproof glue. $40/sheet.
I think there are some choices but my choice would depend on the project. Something like the deck where there is so much work I would use what the dealers or pontoonstuff recommeneds. For other projects my choice would depend on the location of the wood. I used MDO on my seat rebuilds and the look great and are working out great.

Re: marine plywood
Posted: Wed Feb 04, 2009 7:21 pm
by fishnboy
thanks for all the advice.This site has helped me get some so good ideals.my plywood thats is on the boat has no soft spots but when I pull up the carpet it pulls the top layer of plywood up.dont get me wrong it's not that bad.But im scard that when I go recarpet it it will show.and I could maybe lay some fiberglass down and sand it.But the boat is 88 model and I feel like since im putting new seats in it I should do the hole project right,but I realy dont have a lot of money to spend on it.HOW LONG DOES A DECK ?it has been kept in pretty dry.and the deck is pretty soild.
Re: marine plywood
Posted: Fri Mar 06, 2009 6:01 am
by oldmn19
If you pull up the old carpet and some wood then I would fill in those area's with fiberglass gel. It's inexpensive and will out last the wood. Now this is based on GOOD solid wood under the damaged area's. If the floor is de-laminating the only real fix is new Marine grade plywood.
