# Decking for Raft Trailer - Treated Plywood



## Yukon77 (Jan 30, 2013)

I've searched and read a few posts on the different type of treated plywood "marine vs. standard big box store stuff". My purpose for wanting treated plywood is for the top of a trailer deck to haul a urethane Sotar raft. Everyone suggest "marine plywood", but it is not easy to find.

If you walk into any local big box store and ask for marine plywood, you are directed to what I would call the normal construction treated plywood - the stuff that is sort of greenish. My question is has anyone used this type plywood for a raft trailer top and does this green treated plywood mare up a raft bottom or have chemicals that are bad for the boat fabric (urethane in my case). Many thanks.


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## David Miller (May 23, 2010)

Just use CDX and soak it good in linseed oil and it will last ten years. For the price that's the best deal. It can be done better but the cost just isn't worth the expense.


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## Soup76 (Aug 19, 2009)

David Miller said:


> Just use CDX and soak it good in linseed oil and it will last ten years. For the price that's the best deal. It can be done better but the cost just isn't worth the expense.



X2. I did use 1/2" treated plywood for the sides on my trailer but that was it. The decking I used 3/4" CDX and sealed it with decking stain. Then I covered it in outdoor carpet. Lasted 8 years. Redid it this year and only had to replace the outdoor carpet. I did reseal the plywood.


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## David Miller (May 23, 2010)

I only used 5/8 and it does sag when I walk on it. 3/4 is nice but it costs too much and adds weight to the rig.


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## Sembob (Feb 27, 2014)

The green stuff probably won't harm your boat but I to would use CDX or even ACX which has a smooth side and fewer voids than CDX. I would for sure use 3/4 the cost difference is very minimal and it will preform better. Try going where the local home builders go and not the box stores. The lumber yards are always cheaper. I like the the idea of an oil like linseed or tongue but there are cheaper ways to treat/ seal the wood. I think it's best to apply enough water seal and sometimes that's easier to do when your not paying a premium for it. I think it's best to put a couple coats on after construction then repeat a few months later as the wood seems to sop up the oil or sealant as it dries. 


Jim


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## Yukon77 (Jan 30, 2013)

The CDX I'm finding in the big box store is the green stuff. Since its already been pressure treated with something, and has a somewhat "moist" feel to it, I wonder how it accepts added wood treatments that folks are recommending. I do know that regular pressure treat lumber doesn't take painting like regular lumber. Last thing is want is to find I have coated the wood deck with something that doesn't dry completely


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## Sembob (Feb 27, 2014)

Don't treat it. It won't need it. If it dries throughout the summer then maybe treat it. That's weird that it's sold as CDX but it will still work. It does react with some metals but that probably won't be an issue. But as far as treating goes it's done. 


Jim


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## Soup76 (Aug 19, 2009)

CDX and pressure treated plywood are two completely different products. CDX is not treated with anything, it just has exterior grade glue holding the veneers together. You will know the difference by the price. Pressure treated plywood is about the double $$. I would treat CDX with something just to double its life. Pressure treated I wouldn't bother.


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## dport (May 10, 2006)

The green pressure treated stuff may not harm your boat, but if you or anyone else picks up a sliver or othere scrpe or puncture there is a very great chance of infection. That green chemical is poison!!!! This comes from my 22 years as a carpenter who has used this plywood on cooling towers for power plants, do not use it.
Be safe out there...


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## MT4Runner (Apr 6, 2012)

Green treat is "CCA" = Copper-Chrome-Arsenic.

You don't want a sliver from it!!


Definitely go for an exterior plywood and linseed oil.


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## SummitSurfer (Jun 23, 2010)

Buy pressure treated ply wood, indoor outdoor carpet wood, staple underside and go have fun. On year five of success with this method. If it gets muddy grungy, bucket rinse with water..your good to go. Its not slippery like some treated plywood and drys out pretty fast.


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## swiftwater15 (Feb 23, 2009)

*MDO Plywood*

If you can find it, use MDO Plywood. It has a smooth face made from some kind of paper-like product. It is used for outdoor signage, and most of the raft trailer manufacturers around here (the rainy Northwest) use it. It seems like it would be slick, but really isn't in my experience. To finish it, I take high-quality marine varnish and thin it way down so it soaks deep into the wood, and doesn't leave a film. Either epoxy or lots of varnish on the exposed edges and you are good to go.


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