Anybody ever just use paint on exterior?

[CLChastain]

A builder of a Glen-L truck camper had this in his build description:

"For the exterior sides I used 4 x 8 x 1/8 thick door skins, to protect the skins from moisture penetration, I painted both sides and ends with two coats of outside C.I.L. undercoat house paint, I also painted the entire framework with the same paint, to inhibit moisture penetration. After construction was completed I painted the entire camper with a premium outside house paint."

Photos here, and the camper looks good...
https://glen-l.com/campers/rv-picboard/rvpic6b.html

Anybody know what he means by "4 x 8 x 1/8 thick door skins..."? Is he talking about 1/8" lauan plywood, which is commonly used to make household doors?

[Jdw2717]

I used oil based primer and latex house paint on mine. It lives in the garage when not camping so it has held up great. Both were Sherwin Williams brand so it wasn't cheap stuff. Plus, the stuff has been used on wood siding forever so it's made to take the weather.

[noseoil]

"Door skin" is just a generic term for 1/8" plywood. Typically it's relatively cheaply made, but has a decent finished face since one side is seen. I'm not so sure I would trust it in an exterior setting, unless I could find out about the glue it's being made with during manufacture. An interior glue wouldn't be my first choice for a panel exposed to the elements, regardless of the finish system.

I've been pleased with the quality of the 1/8" Baltic birch available at a local hardwood supplier, but I'm using it in an interior application & covering the outside with .040" aluminum. There aren't the considerations of water damage from rain, etc. which come into play with an exterior application the way it's being installed. The down-side is the sheet size (5' X 5') and framing issues which need to be taken into account to use it properly. Most USA stuff is 4' X 8' for sheet sizes, so the 5' X 5' is a bit odd in some locations. I'm paying about $.50 a square foot for the 1/8" BB I have access to in the build.

[Tomterrific]

I used oil based primer and white Rustoleum over the entire exterior. The roof bothered me. I think the rustoleum is too hard for the expansion and contraction it will suffer so I put elastomeric roof coating on the top over the rustoleum. Camper lives outside in the sun, rain and snow in Ohio.

Thoughts:
White reflects so much heat it may contribute more to the camper staying cool than the foam roof insulation.
I used lots of PL construction adhesive to build and every seam was caulked with urethane caulk. The camper would float upside down.
The elastomeric roof coating is VERY white and never gets hot even in direct overhead sun.
I have second thoughts about the rustoleum so acrylic latex may be just as good if not better.

Tom, The recent.

[CLChastain]

Jdw2717 and Tomterrific, what was your exterior walls made of that you painted?

Since reading the Glen-L description some years ago, I have considered -- assumed -- an exterior skin of 1/4" exterior plywood. Seams and edges fiberglassed, the whole thing sanded as smooth as possible, filled where necessary (Bondo, microballoons or some such... I need to research this), sanded again and the primed and painted several coats (foam-rollered on) with light sanding between. I want a smooth, satin finish, neither flat nor glossy, in a bone or cream color. I had planned on painting on a white "liquid" rubber roof coating. I'm really paranoid about putting holes in the roof, and plan to avoid doing that if at all possible, but I still want the rubberized roof coating.

It sounds like painting the exterior is a viable option for my travel trailer design.

The main reason this is still a question for me is because the 1/4" plywood would add up to a lot of weight, compared to the aluminum skin that was originally on the trailer. So I've been doing a leisurely search for affordable, lighter-weight alternatives. If "door skin" panels would work, I'm assuming that would be about half the weight of the 1/4" plywood, though doubtless not as light as aluminum.

I don't know at what point my design, if built, would become too heavy for the axle.... That's another thing I'm paranoid about....

[Tomterrific]

My exterior is thin, cheap underpayment from Lowes, less than 1/4". The roof has 3/4" ribs across with the same ply as a ceiling. There is Styrofoam as insulation and to make a weak sandwich. The side walls have battens to stiffen them where needed. Amazingly light weight and strong.

New Tom

[Jdw2717]

My walls are 1/4" from 84 lumber that was better quality than Lowe's/Home Depot (actual plys not just filler wood) with 3/4" pine sandwiched in between. 1/8" birch for the ceiling and roof with 1.5" stringers and foam insulation sandwiched in between with a 1/2" plywood floor on a metal frame. All that to say that my 5' x 9' camper is around 750 pounds empty. I think you can look up weights of different plywoods if you want to figure how much weight you could live with / save.

[Kaz]

Premium oil based primer( 2 coats w/sanding between coats) 4 coats of rustoleum blue paint slightly thinned and a splash of boiled linseed oil applied with a premium 4" roller and sanded between coats, made it through it's 1st season no problem. Always garaged and going to get a final sanding and clear-coat this winter. Looks really sharp but it's like owning a wooden boat. They need constant inspection and address problems immediately. But you change colors anytime.

[CLChastain]

The finish looks great... But, a question. I've always heard not to use latex over oilbased anything... I wonder why, given that your project turned out so well...

[Kaz]

The finish looks great... But, a question. I've always heard not to use latex over oilbased anything... I wonder why, given that your project turned out so well...

Oil based primer and rustoleum oil based paint. I don't trust latex paints. Latex peels and oil base cures harder, little messier and longer times between coats but It took 9 months to build for that reason. Learned patience in waiting for glue and paint to dry. Going to build a tongue box this winter and use the same methods. I don't know how it would hold up in the heat out west but seems to be well suited for the weather in New England.

[mikeschn]

The Giant Teardrop was painted with The Rot Doctors boat hull paint. I thought for sure that would have kept it dry.

But alas, it delaminated. I am now a firm believer of having a membrane between the elements and the wood. Even if it's just canvas and TBII.



Mike...

[Tomterrific]

I was/am afraid of micro cracks in the oil base rustoleum roof paint. I used elastomeric roof coating with the thought it would put a thick stretchy membrane over the roof.

Mike, What plywood delaminated like that? An unpainted piece of raw underpayment spent an entire fall, winter and spring outside in Ohio weather with no damage.

Tom

[CLChastain]

Hubs and I made a little A-frame shed in the back yard to keep stuff out of the weather. We used quarter inch roof sheathing plywood from Lowe's. There was, shall we say, a "design flaw" in it that didn't come to light until we built it. (I was the designer, and I take full responsibility.)We couldn't figure out how to fix it, so we didn't bother finishing the shed; no roll roofing, no paint, no nothing. We decided we would just use it as it was until it fell apart. It weathered and turned gray fairly quickly but it took years for delamination and rot to occur. Of course, it just sat there and wasn't subjected to the stresses of "life on the road..."

After reading up on finishes here and elsewhere, I've been considering the Glen-L builder's "door skin" approach for the exterior, but with a painted canvas finish. But from what I've seen, every little surface flaw shows through. Not sure what to do to the door skin material to make it flawless enough to cover. I also wonder about getting the canvas stretched tightly enough to prevent wrinkles when wetting it out with Titebond II and/or paint. Finally, would painters' drop cloths (affordable) be a sufficient substitute for canvas (expensive by comparison)? People who decorate with drop cloths warn that they can rip when you upholster with them (stretch to staple) and they sometimes have a seam in them.

One thing that occurred to me was that the Glen-L builder's truck camper, sitting there in the truck bed, wouldn't be subjected to the same road stresses as a trailer. At least, that's my assumption. That might enhance the longevity of an exterior paint job as the sole finish....

[dano]

Houses are built with primer exterior and house paint. They're outside in the weather all the time. If you had a trailer painted that way would it work ? What makes it different? Is it because the wood is thinner.?

[Tomterrific]

I feel the problem with our trailers is the roof. It will be subject to 'ponding' water on the top where a house will only have a random splash of water. This pool of water has plenty of time to seep through any micro crack or porous paint and soak into the wood. Layers of water proof paint is my solution but is yet to be proven. One year outside with rustoleum as a topcoat. Now a solvent based elastomeric roof coating painted over the rustoleum. I will tarp the top over the winter but the poor camper has a brutal life outside.
N Tom