Sealing plywood

bspeth

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New to the resto forum,is there a way (product) I can just paint onto plywood to make it stand up for a long time? Making a deck out of 3/4 ply for my 12' tinny in between the benches. Don't want to spend a lot as I will probably end up in a 14' before long.Thanks-B
 

jigngrub

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Helmsman Spar Urethane, get the indoor/outdoor grade.

There are better (much better) sealers, but for what you're going to use it for and the length of time it sounds like you want it to last (until you get into the 14'er) the spar will work fine for you.
 

Woodonglass

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What do you mean when you say "a Long Time"??? A thin coat of Spar varnish on a deck that will have substantial traffic is not gunna last very long IMHO!!:eek: I'd think you'd need a more substantial coating. Give us some more details as to time span and usage and you'll get better answers. Again, it's just my opinion. When you say you don't want to spend a lot, what IS your budget??
 

jigngrub

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Thin coats... thin coats... I know a guy that used thin coats of spar urethane to seal his boat deck once. He claimed he sprayed 4 thin coats of spar urethane on his boat deck to seal it that spring before he installed it. When we removed the decking that fall the bottom of the decking had orange fungus growing on it. He claimed that happened because he had to thin the spar down so much to get his spray gun to shoot it.

Had he stopped and read the manufacturers application instructions printed on the back of the can he would have realized he needed to brush or roll on 3 to 4 coats of unthinned product to get the exterior protection he needed. The printed instructions on the back of a can of paint product may just be the manufacturers opinion, but sometimes it really pays to follow them... aint that right Dave?;)
 

bspeth

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Id like to spend about 30 bucks for the sealer,so whats the best option for 30.46x30 inches
 

jigngrub

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A quart of spar urethane is about $15 and it'll put 4 coats on that 46x30, spend the other $15 on something else.
 

Woodonglass

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You stated you wanted it to "Stand Up for a long time" How will it be used? What kind of "Abuse" will it get. 4 coats of Spar varnish will not protect the wood very well from dings and scratches and gouges etc. and once they occur water WILL get to the wood core and then problems will start. If it's NOT going to get much traffic or abuse an you're just wanting to protect it from the elements then the varnish should do the trick. Make sure to get the edges really well. Thats where the water will really try to get in.
 

bspeth

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Mostly used to step in and out of the boat,and when we are fishing it is used mostly for cooler storage and tackle work bench.I am going to put outdoor carpet on the top also.
 

jigngrub

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A 46"x30" piece of plywood is a third of a sheet, you could cut that piece out of a sheet and put the rest in the garage and have 2 spare pieces left for when the first one rots out... but sealing a piece up the best you can and just showing your boat a little bit of care will make that third of a sheet last a long time. Seal both sides and the edges real good with multiple coats of whatever you decide to use (you could use exterior grade house paint if you want.

The thing that will kill that piece of plywood the quickest is the carpet you want to put on it. Carpet absorbs and holds moisture, so if you don't seal that wood real well the moisture will migrate from the carpet to the wood.

If you'll keep your boat covered, garaged, or just turned over bottom up to keep the rain and snow off the carpet on the plywood and keep the carpet dry... that plywood will last until after you get the 14 footer.

If your boat was bigger with more wood to seal I'd suggest sealing everything with epoxy resin for a lifetime of protection, but being what it is any good grade exterior sealer or paint will work for what you want.
 

Ned L

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3/4" ply for a 12' boat??? Bit of overkill there. ............. I'll leave the "sealer discussion" up to others.
 

gm280

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3/4" ply for a 12' boat??? Bit of overkill there. ............. I'll leave the "sealer discussion" up to others.

I was thinking the same thing. The weight of the plywood alone is amazingly heavy. And such a small boat hull, I certainly wouldn't go that thick. Depending on the distances needed between any type support, I would look at 3/8" to see if that would suffice. JMHO!
 

jigngrub

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A sheet of 3/4" ply weighs 75 lbs., the 1/3 sheet bspeth is going to install in his boat is 25 lbs.

About the weight of 2.5 bags of ice or a nice sized catfish.
 
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bspeth

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25 lbs in between the benches will be perfect for ballasting with my boat and motor/gear I think,thank you for the replies.-B
 
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