How would you waterproof plywood?

[jryoung]

After watching about a dozen DIY videos for building a truckbed drawer system I've decided I'm going to build one for my M1102 trailer. However, most those truck bed systems are under a topper and mine will be exposed. Other than a simple exterior housepaint what other products would you recommend for sealing the plywood (an other lumber pieces) I'm going to be using for the drawer system?

 

[Brauee20]

Get exterior rated wood, let it dry out. Then prime it with rubberized spray. Or use a cement board, hardi-panel etc instead of the plywood.

That's what we did on a couple small projects when I lived in Florida.

 

[Nutrioso]

JR,
I have a waterproof Truck Vault that is excellent. I believe they use MDO instead of plywood and coat it with Line X bed liner.

 

[Bluejeep]

I used to work in a shop as a spray tech for Rhino Linings. I sprayed several diy projects from trailers to boats to truck tool boxes. If they leaked when I was done, it was from a design flaw, not a failure of the product.

FYI, spraying These custom jobs was very expensive

 

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[mtmuley]

The problem with plywood is it's plywood. Any penetrating moisture will delaminate it. The edges especially. I suppose a marine grade finish would work for awhile. Or, look into sheets specifically made for forming concrete. Plywood made for form work is made to withstand multiple uses, and I can't think of a more unforgiving use of a sheet material. Pressure treated plywood is available, but pretty ugly stuff and not sure how it would accept a coating. Sounds like being a drawer system, the truck bed liner coatings might inhibit the operation of sliding components. mtmuley

 

[Pelican]

Marine plywood is expensive, but holds up really well in wet conditions and to sun exposure.

 

[dcopas78]

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Ever thought about using something like this? Its pricey but you can get all types of materials from them and have used the sheeting and angles on a lot of projects. It's easy to work with and you'll never need to replace it. I order stuff from them all the time. Good company to work with

 

[LopeHunter]

Have you looked on Craig's list? Would something out of a machine shop or hardware store that was closing work, for example?

 

[kansasdad]

Instead of plywood, could you use composite deck material like Trex? Fully weatherproof material, but I don't know if it comes in big sheet-like dimensions.

 

[belshawelk]

Seafin Aquaspar. Its a clear paint on finish that is used in Marine applications for wood boats or wood accents. Not cheap but I use it on my outdoor kitchen cabinets and its works. Mine are not plywood but worth looking into

 

[Brittany Chukarman]

Gluvit is a good product for sealing plywood drift boats.

 

[Carnage2011]

Use a marine grade plywood and coat it with resin. I’ve built some custom drift boats with a friend and we use it all the time. Some of them have been on the water for 10+ years with no issues.

 

[hank4elk]

Marine grade plywood & resin. No open edges. Solid hardwood?
I made some years back from Finply & it worked well under a topper.
The wood products we used in earlier days sometimes lasted longer than anything now, & some were a big mistake.
Nothing will last if it is exposed all the time. IMHO. Maybe redlead paint......

 

[blueridge]

Our local Home Depot has 3/8"x4x8 pvc panels. Build your frame with birch plywood or MDF and wrap it with the pvc, being sure to caulk all of the joints really well. (I'd try to find a cheap topper as well.)

 

[Mp5Mp5dw]

I have never used that FlexSeal stuff, but the commercials are cool!

 

[jryoung]

View attachment 103253

One of the best videos out there was done with Flex Seal, I gave it a good laugh and am not trying to find something realistic. LOL

 

[ringer]

I built a marine plywood drift boat in 1982 that is still running rivers in Oregon. I used marine plywood and used epoxy paint over it. 3/4" marine plywood is available and not that expensive IMO. Costs more than wafer wood from HD but well worth it.

 

[hank4elk]

OSB,MDO,chip board is OK inside OUT of weather....maybe.LOL
Marine grade plywood has been quality standard for many years. I have things 40 yrs old still together.,,,in the weather.
I do know nothing of new products except most don't last or do what they claim.

 

[shanny28757]

Try marine grade plywood. Then paint with something that will seal it. The edges will be a problem because water just wants to get in between those layers.