Undercoating

[Creamcracker]

Has anyone used and had success with the rubberized solution that can be sprayed on the underside of cars? It's available at the local auto supplies by the can. Does it stick well enough to the underside of the wood floor to form a good protective coating?
Philip

[sauljordan]

I think Dee Bee used something like that. Go to his web site where he describes it.

[SteveH]

Philip,

I've used a lot of it on the underside of old car fenders to reduce what we call "stars" in the paint from stones thrown up from the tires, and it's a good product for it's intention. Sticks really well. However, after using the roofing tar on the underside of my teardrop body, I believe the tar is much better suited for the wood. The tar goes on wetter and therefore soaks into the wood and really protects it. The undercoating, I believe, would not soak into the wood as well. Also, the roofing tar is cheaper. The only down side is, the tar is a PITA to apply. I did my floor upside down before I started the rest of the build and it wasn't too bad.

[Randy G]

Do you apply a sealer to the plywood before using the tar?

[doug hodder]

Philip,

I believe the tar is much better suited for the wood. The tar goes on wetter and therefore soaks into the wood and really protects it.

Randy...any sealing of the wood would inhibit the penetration of the tar product....it kind of depends on your environment. I don't use the asphalt based type materials, however I'm in a very dry location and don't do a lot of "wet" travelling, an advantage to living where I do, but I'd think you'd want maximum penetration to seal it up...I'm also indoor stored...Doug

[Lazybones]

My friend Dave and I used an oil primer and then a high gloss oil paint. We put both on before mounting the floor to the frame. In my oppinion this is as much protection as any trailer would need.

[Jiminsav]

Has anyone used and had success with the rubberized solution that can be sprayed on the underside of cars? It's available at the local auto supplies by the can. Does it stick well enough to the underside of the wood floor to form a good protective coating?
Philip

I used it..it don't stick to wood..go with a tar based, painted on product.

[Big Dave]

I would have to agree with lazy, I deal with plywood signs all the time that have been in exposed to all the elements for years and the only failure I have ever seen is on the edges or mounting holes. I think that a quality latex primer and acrylic latex paint really should suffice. If it's good enough to keep wood siding on a house dry for decades it should keep the sun protected bottom of a mostly stationary trailer from rotting. I would be more worried about sealing the bolt holes and the gap between the frame and the ply. Oh, and I would paint the ply before assembling to the frame.

If you really wanted to overkill it you could put another sheet of aluminum between the plywood and the frame.

[Creamcracker]

Just following up on this -- I bought a can of Duplicolor Undercoating to test on a piece of wood --- I also called Duplicolor customer service and spoke to a tech there. ---- who said "It will work well on wood as long as the wood has not been primed or sealed/varnished in any way. It will soak into bare wood and it has great adherence properties. It can be painted after it has been applied." My test piece looks great and doesn't peel off the wood. 2 cans at approx $4.00 a can will take care of it.

Philip