Have you tried high grade roll on paint?

[SteveRogers]

I've seen a beautiful construction (not on site, but most likely a member here) of a nice build, but I expect the aluminum skin to be nearly tough for me to install given my lack of assistance. Because I work in automotive damage and refinishing, I was curious what you thought about treating the sides and roof like a car. I coated MDF speakers with automotive paint and they functioned perfectly. Will this hold up? Of course, UV-wise, it would. Any ideas would be greatly appreciated. I could even apply some primer surfacer because urethane paint cannot be applied to bare wood. Have you tried this or something similar, such as a high grade roll on paint?

[Tom&Shelly]

Several of us have used Monstaliner, which is a roll-on bed liner. We fiber glassed the wood, and used a high quality marine primer over that, then the bed liner.

Worked great!

Tom

[nbcarey]

Skin your teardrop with fiberglass and marine epoxy (System Three, West, etc.) Scrub the amine blush off and shoot it with a 2-part LPU (linear polyurethane) like Awl-Grip (marine) or Axalta (née DuPont) Imron (automotive) and it will last a long, long time.

https://www.axalta.com/corporate/en_US/ ... imron.html

https://www.awlgrip.com/homepage

You can roll/brush the stuff, but it's tricky. Also toxic — it offgasses cyanide, so serious PPE is required.

[tony.latham]

Will this hold up?

It'll hold up if you fiberglass/epoxy the cabin first.



Otherwise, the plywood will probably check.

And I, too used Monstaliner.





Tony

[S. Heisley]

I used top deck marine paint with a couple coats of marine epoxy-based primer first.
The paint has been on for 12 years now and still doing well.
I had a small age crack show up last year and all I did was fill it with TitebondII (waterproof) and then go over it with the top deck marine paint once the Titebond was set.
Someone took a knife to a small area of my roof last year and I haven't fixed that yet, but I think that will be okay, too. (I'll have to fix that before I camp in the rain!)

[S. Heisley]

Oh! It's been so long, I almost forgot! There was a fellow member who hasn't posted for several years but he was a professional automotive painter and used car paint on his teardrop to match his tow vehicle. It's been so long that it would be difficult to find his build but I think his member name was Gaston.

[Mark Gunter]

As a former automotive finisher, I’ve plenty of experience with fiberglass, Bondo, lacquer-based primers and acrylic lacquer, acrylic enamel, and alkyd enamel finishes, with and without hardeners for the acrylic enamel. I don’t have much experience with the current automotive finishes because acrylic lacquer and acrylic enamel was in vogue during my automotive career, but I have some thoughts for you.

First off, I *would not* dream of finishing the wooden skin directly with automotive or other finishes. Not that it can’t work (for a while), but for lasting durability I think you should resign yourself to doing a fiberglass or a “PMF” skin over the wood before finishing. Although I have fiberglass experience, I chose “PMF” for my build because (1) the large size of my build, (2) the ease of application, (3) it was a totally new challenge for me.

I believe I can say with complete confidence that if you do your fiberglass or your “PMF” correctly, you will get a beautiful finish with automotive finishes, nicer than many others get, because you will be spraying rather than rolling.

In my own build, I did a pretty neat looking job with the “PMF” and I sprayed my finishes using an airless sprayer with latex. You can check out my build journal via the link in my signature.

[twisted lines]

I used the Monstaliner over,

PolyU UV GLOSS.jpg (53.15 KiB) Viewed 509 times

then this: (Wood) till or if? I put a Picture up.

Sprayed it!
They Sell A good Gun and Have Directions for thinning

[Mark Gunter]

To clarify: I know you can can make successful woody builds, and I’m familiar with spar varnishes, etc. Been working in many areas of the film finishing industry for over 50 years beginning with automotive finishes, then wood finishes and dabbled in industrial coatings from time to time. Kudos to those who build and maintain woodies.

In general, exterior varnishes, and polyurethane in particular, eventually will break down and crack and flake and be ugly asf and needs some labor-intensive care to restore IMHO. For many outdoor wood projects I much prefer plain oil finishes rather than oil varnish or urethane varnish. Annual maintenance yes, but no flaking.

For a camper, I wouldn’t personally go with a finish over raw wood. Use fiberglass or PMF which is more resistant to damage from any wood movement and easily made to be waterproof. For the finish, a good automotive finish done properly should be fine. I’d be confident with automotive finish over fiberglass (been done forever with corvettes) and wouldn’t be wary of using it on PMF either, though I think it would be pretty costly to use enough sealers and finish to properly saturate the canvas.

[Tomterrific]

I followed advice and used thined polyurethane varnish over all my wood. I then used oil based primer and white Rustoleum for a top coat. It held up for a while. The Rustoleum was a hard finish. The primer didn't stick all that well to the poly. Small cracks showed up in the finish.

Now my camper sits in the sun and rain all the time. I have learned a bunch about wood rot. I think I should have used a high bond primer and water based house paint. Part of my problem was too much wood completely encapsulated so if moisture got in it could not get out.

Tt

[Pmullen503]

A long lasting finish over wood pretty much has to be glassed, that is resin plus glass cloth. Then protect the glass from UV with paint or a UV varnish. Speaking from experience with "bright" finished boats, you'll need to scuff and re-varnish every two to three years if you choose a clear finish, longer if you can garage your camper.

Any finish over bare wood or ply will need even more maintenance.

Just as an aside, with any camper, spend some time on the construction details to make sure water can never stay in contact with any surface longer than necessary. That means good design around windows, doors and hatches so no water can pool. That means drains and drip edges to direct the water away.

Campers die because water got someplace it shouldn't and stayed there too long.

[Woodbutcher]

Back in 2010 or so a paint manufacturer expert posted about using Exterior oil base polyurethane base as a finish. That is the base before any color pigment went in. I was in the process of building a light weight woody teardrop at the time. I was using furniture grade 1/4" mahogany plywood over a soft maple skeleton, no inside plywood or insulation. I applied a coat of the above mentioned finish to a large scrap of the mahogany, and tossed it outside to spend the fall and winter in the weather. It was rained on, buried in snow and the sun beat on it. It survived very well. Only some problems around the edges where there was no finish on the plywood edge. So I went ahead with this finish on the sides of the Woody, The roof and hatch was covered with marine vinyl. I used this trailer for 2 years as it was. Then in year 3, I scuffed sanded the poly surface and added a coat of Helmsman. I did this every other year for UV protection.
The cost of this experiment at the time, was 28 bucks. So are there better options, probably, but they all come at a greater cost and more up front work. What ever you chose, just do the best job of building a good solid structure that will not hold water anywhere and you should be fine.

[TCJ]

I haven't painted my teardrop (yet?), but if I do I'm thinking about 2-part product from Alexseal, mostly because it doesn't need to be sprayed. If it works in the marine environment it'll probably be fine on a teardrop.
https://www.alexseal.com/
https://youtu.be/jFLsOR9riM0?feature=shared

[philpom]

I went the PMF route to prevent checking of the wood and applied Sherwin Williams Duration acrylic latex paint. Been just sitting outside in the driveway for over a year and just fine. Not sure how automotive paint would do, my impression is that it's a much thinner coat.