Sealing the floor deck

[DestinDave]

I'm interested in your thoughts.
Aside from the black roof coating, what else have builders used to seal the underside of the floor? I'm considering a couple coats of truck bedliner or Interlux 2000 epoxy primer.

[TimC]

Just a thought... Check with local roofing contractors that do EPDM rubber roofing jobs. They might have a left over from a roll that would fit nicely. New EPDM is kind of pricey. A 10'x20' piece from Menards here is $120. https://www.menards.com/main/doors-windows-millwork/mobile-manufactured-home-parts/mobile-home-exterior-products/roofing-accessories/10-x-20-epdm-rubber-roofing-roll-45-mil/p-1444444062611.htm

[yrock87]

Epoxy baby! two coats of marine epoxy on the bottom of the floor. so far so good.

[tony.latham]

Epoxy baby! two coats of marine epoxy on the bottom of the floor. so far so good.

I agree on the epoxy and so do the wooden boat guys.

Tony

[working on it]

• As is my habit, I typically try to re-purpose leftovers, or items I have on-hand anyway, for projects I am doing. Since I was primarily interested in cars and trucks, for my whole life, I naturally have "automotive" stuff around, and familiarity with their uses. I intended to build my trailer using nuts and bolts (where possible), some automotive parts/equipment (if practical-most weren't-), and automotive paint (or related-tractor paint).
• When I built my trailer, I did so in a friend's home-shop, where many automotive projects were always going on (hundreds, over the years), and I used what we had on hand there, basically what I had at home, but more of.
• After I painted the frame, using rattle can Rustoleum, and installed the floor, I used spray-on automotive undercoating to treat the bottom, coating any and all surfaces under the trailer. I used Rustoleum undercoating, which we used to protect floorpans and such on race cars, since the new metal would quickly rust if uncoated, and this spray-on would prevent that, and also add some sound-deadening, without any weight penalty, which is not wanted on a racecar. With safety glasses, a dust mask (I'm used to vapors, they don't bother me), and gloves on, I used 4-5 cans of it, waiting 15 minutes between coats, to do the trailer bottom. Frame, bolts/nuts sticking thru, and the bare plywood were all sprayed, with multiple coats. And later, at my home garage, when I installed the interior, I would use more spray undercoating to protect the holes and hardware, that penetrated thru the floor.
• I've used spray-on undercoating on all my cars and trucks for years, and never had any rust underneath. Short of using bedliner under the trailer, I think that it protects just as well as anything. I had used some other undercoating before, that dripped badly, and being more "asphaltic" in composition, really stunk, while spraying it on, but the Rustoleum, not so much. I keep some on hand, to touch up my truck's wheel wells, and the trailer underside, if I detect any rock damage.

• 

  undercoating.PNG (75.28 KiB) Viewed 1627 times

  Rustoleum spray-on, easy and works fine, w/o the mess

[DestinDave]

Thanks for the replies, guys.. I'm leaning toward the Interlux epoxy, mainly because I've worked with it a lot in the past and, anything good enough to be in saltwater for a couple years is good enough for the occasional road-bath..

[DWT77]

I am in the process of building mine now. I went with fiberglass cloth and epoxy. Then sprayed it with raptor bed liner. Hopefully it will last a long time

http://tnttt.com/viewtopic.php?p=1201854#p1201854