Wanting to make my plywood on my trailer waterproof/weather proof. Paint? Epoxy?

jwiereng

Active member
How much west system epoxy is required to do a whole sheet of plywood?

I would like to know ballpark how much resin to budget for/purchase
 

Rbertalotto

Explorer
Depending on where you live, considering temperature extremes and humidity, it matters not what you coat with if you use plywood with the wrong glue. Interior plywood, no mater what you do to it, up here on the seacoast, it will delaminate. You might be lucky and get away with using "exterior rated" plywood......But we really should be using "Marine Grade" plywood for all these projects.
 

jim65wagon

TundraBird1
How much west system epoxy is required to do a whole sheet of plywood?

I would like to know ballpark how much resin to budget for/purchase
It was so long ago, but I think we used a gallon of each part of the epoxy mix to do every panel on the CrowsWing.

For what it's worth it's all held up very well for its 38,000 miles and 10 years of use

Sent from my SM-G960U1 using Tapatalk
 

IdaSHO

IDACAMPER
Are you glassing it? Or just saturating the ply?

Assuming you are using a proper marine ply and no glass, I suggest a minimum of 3 coats, at roughly 250sq/ft per gallon of epoxy.
Any other ply, figure on 5 coats, and roughly 100sq/ft per gallon.

If you are glassing and know what you are doing, you will likely need to double those volumes to get full saturation and build to bury the glass.
If you are glassing and have never done this.... triple those volumes.

Those figures are averages, all needed to seal and build thick enough for a smooth shell.
You should be sanding in between the first few coats if you want the result to be a smooth finish.

Depending upon your plan, a CPES could help as well.
Clear Penetrating Epoxy Sealer.

Is a thinned epoxy that penetrates, and is VERY thin. Likely 400-600 sqft per gallon.


I use Aeromarine by the way. The 300/21

And always have a couple of the 1.5 gallon kits with pumps on hand
 
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vintageracer

To Infinity and Beyond!
Try JM Huber Advantech subfloor material instead of plywood.

Works great, water resistant, easy to use and available at your local Home Depot.

I had a piece of this stuff in water in a 55 gallon barrel for over 2 years when I built my house without any change in the material.
 
I used west systems epoxy to glass over plywood when I rebuilt the roof of an old pop top trailer. I finished it with a white roof sealant for Fiberglass RVs and I had it for 4 years after the redo, stored outside for 3 and it looked essentially the same when I sold it. I don’t think the fiberglass factor would change too much regarding waterproofing, if anything it would just ensure you lay down a thick enough layer of epoxy. I also used west systems epoxy on a marine plywood/fiberglass kayak, I build that in 2010 and it’s still doing great. Sanded it and put on an additional layer of resin recently but only because of it being dragged across rocky beaches fully laden many times. Otherwise it would have just needed urethane for UV protection
 

Alloy

Well-known member
In addition to a backyard fleet and a nice 30' Santana, I have an aluminum snowmobile trailer 8.5'x20' decked w/ 5 sheets of treated plywood. The original deck (CCA) lasted 10-12 yrs, but the replacement (CA) cracked and warped in one year. It lives in the sun. After being forewarned of the present treated plywood, I've invested in ABDouglas. My thought is to epoxy the sheets top and bottom with perhaps CPES or suitable paints. I don't want to do this repeatedly. The trailer is in good shape; now if I could keep a deck on it... I'd appreciate your thoughts before purchasing a mistake. thanks
FYI....CCA is compatible with aluminum but others like ACQ, CA-C (copper is the main ingredient) used for lumber are not.....
 

rruff

Explorer
I don’t think the fiberglass factor would change too much regarding waterproofing, if anything it would just ensure you lay down a thick enough layer of epoxy.

The glass makes that layer much stronger and resistant to abrasion and cracking.

For a decent cheap epoxy, try Ebond. Thayercraft and Fiberglass Supply for cloth.
 

MOAK

Adventurer
Wow- a very old thread. I built my trailer 12 years ago using 1/2” marine grade T-1-11 with an aluminum floor and a custom fitted tarp for a cover. I used a paintable silicone hybrid caulking to seal the corners and a pure silicone caulking at the floor corners. Using top of the line latex house paint tinted to match the tow vehicle. Latex house paints expand, contract and flex with wood, Epoxies do not.
 

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