In my initial interior painting tests, I experimented with several readily available (Home Depot/Lowe’s/auto parts stores) spray paints for plastic.
While Krylon Fusion seems to be the only one that says “this is made specifically for plastic and bonds chemically with plastic” (paraphrasing the text on the can), I have read and been told that Rust-Oleum 2x Painter’s Touch bonds with plastic in a similar way.
The Krylon Fusion is many people’s go to, but it comes in very few color choices.
The Rust-Oleum Painter’s Touch 2X Ultra Cover has MANY more color choices (though you are still much more limited than mixing your own or using a Latex wall paint).
Some people have mentioned that Valspar (carried by Lowe’s) also makes some sprays, but the colors were so few (and nothing on the can indicated that the product would be *great* on plastic), so I didn’t include it in my test.
After doing some thorough surface prep with xylene and acetone (which actually “etches” the plastic for better adhesion as well), I sprayed different single applications and combinations of paint on the backside (where the experiment won’t be visible in the final install) of my two plastic sliding window inserts on our 1972 Tradewind. After waiting two weeks (plenty of time for the paints to completely cure), I did some scratch tests.
My final application includes several clear coats, which I experimented on separately after making my initial spray paint selection. I also tested various finishes and brands for the clear coat: matte, satin, semi-gloss, gloss, Krylon Fusion, Rustoleum 2x, Rustoleum Enamel clear, Duplicolor Acrylic, etc.
I did a similar paint test on the vinyl coated interior skins, examining how the “plastic specific” spray paints adhere to the glued-on vinyl coating.
The original covering for many vintage Airstream interiors is a substance called Zolatone that is actually still available (though more difficult than regular paint to apply and fairly expensive). Some interior skins also utilized a glued-on Vinyl “grass cloth.” Our Airstream has the factory adhered vinyl. Some people choose to strip the vinyl from the aluminum skins, but unless you’re actually going to leave the skins aluminum (not painted), I think it’s best to paint the vinyl coating, especially since it’s so durable. Not only that, but getting paint to stick to bare aluminum is quite difficult, even with the “aluminum specific” primers and etchers available.
I have seen a few owner’s complaining about the vinyl coming off of their interior walls over time, but ours is adhered incredibly well, even after being stored in the PO’s barn and covered in various barnyard animal scat collections (be-do-bop-de-doo).
When I cleaned the skins (trying Simple Green, TSP, Goof-Off (xylene, 2-ethanol), and paint stripper), the vinyl stayed completely adhered until I left the paint stripper on for extended periods of time (lesson: if you want to get that vinyl coating off your walls to expose the bare aluminum, use paint stripper, leave it on for a while, and the vinyl will peel right off).
First impressions regarding spray paint on plastic panel/inserts and vinyl over metal skins…
Between the two main brands that specifically advertise “bonding to plastic,” the Krylon Fusion does seem to stick a bit better (it doesn’t scratch off as easily as the Rust-Oleum Painter’s Touch 2x Ultra Cover and holds up to a clear coat much better). Places where I put down Rustoleum 2X Ultra Cover Flat Gray Primer before a coat of another color (no matter the brand/type) does seem a little more scratch resistant, but it’s probably just that the scratch is showing gray underneath instead of (very visible) white (the original surface). I think a better primer for bare plastic might be a flat Krylon Fusion. I am not as impressed as I’d hoped with Rustoleum Universal Bonding Primer. It is pretty thin and runs quite easily, though I do still use it for spray painting metal, especially shiny metal.
The Rust-Oleum Universal Metallic is probably the least durable on the plastic inserts and end cap, but somehow the most durable on the vinyl skins. Go figure.
Dupli-Color Trim & Bumper (Dark Charcoal) was a late addition to the test, and after just one day it seemed about as durable as the Krylon and Rustoleum that had been curing for more than two weeks (in comparison, a new color of Rust-Oleum 2X I added at the same time came off like butter when scratched the next day). The Trim & Bumper paint is advertised as having “Fade-X Technology” and also boasts “flexible finish” and “excellent adhesion,” but the colors are extremely limited (like… three colors: black, white, and gray). However, if it’s made for bumpers, I’m hoping it might be the most durable of the bunch? I’m also wondering about it’s possibility as a primer.
After two weeks (plenty of time for everything from the first batch of sprays to cure), I started testing
clear coats. The bad news is that when Rust-Oleum 2X Ultra Cover Satin Clear was sprayed on heavily, it caused ALL paints (every type and brand) on the plastic inserts to crack, bubble, and flake. Seriously. You simply can’t use it on Krylon or Rustoleum applied to the plastic in my Airstream unless you apply many, many very thin, light coats. When used in a heavy application, the Rust-Oleum clear coat did OK for the paints that were on the vinyl, but be aware that it clouded up a bit at first and then cleared up.
The Dupli-Color Acrylic Enamel “custom matte finish” gave much better results. Be aware though, when sprayed on thick, it did cause all the Rust-Oleum flavors to bubble and crack like the Rust-Oleum clear coat, though not quite as badly.. The Dupli-Color Acrylic Matte Clear did very well with the Krylon Fusion and even with the Dupli-Color Trim & Bumper (with minimal curing time; it became as tough or tougher over night vs. having to wait a week). I also like the matte finish of the Dupli-Color better (it’s more “invisible”) than the Rust-Oleum Satin (which has some sheen), but the comparison of the look isn’t really fair as it’s apples to oranges (matte to satin).
Also note that both the Rust-Oleum and Dupli-Color clear coats caused the Rust-Oleum Ultra Cover 2X Satin Aqua (the only actual color in the test) to discolor (both clear coats made it look a bit yellowed).
Like so many things Airstream related, it turns out the “most perfect” isn’t really “enough more perfect” to warrant basing my decision upon the results. Practicality wins out over “the ultimate” once again. To me, there wasn’t a big enough difference in the durability of all the products and combinations to warrant sticking with the winner (the bumper paint), and I just went with the one that I liked the looks of best.
I sprayed the fiberglass rear end cap and part of the rear vinyl skins (everything in the bedroom) with Rustoleum Universal Metallic in “Flat Soft Iron.” It’s a charcoal gray I really like, and it’s got a nice, subtle, metallic sparkle to it when the sun catches it. Since I used Rustoleum for the color coat, I decided to stick with their products for the clear coat in case it might aid compatibility. I used two coats of Rust-Oleum Painter’s Touch 2x Ultra Cover Satin Clear.
Next I painted the plastic “sliding shade” housing in the VistaVue windows with Krylon Fusion in “Satin Dover White” (the only “off-white” they offer, but also close enough to the original color). I also painted the actual vinyl coated aluminum “sliding shades” with metallic copper and finished with Krylon Fusion Clear Gloss (for metallics you need to use a clear coat, because a satin or flat finish clear coat will dull the metallic sheen). I did try four different kinds of “metallic copper” ranging in price from five bucks to fifteen, but all of them seemed to look and perform exactly the same, so now I just purchase Rust-Oleum Bright Coat Metallic Finish by the case from Amazon for anything I’m doing in copper.
You know what I learned from all these spray paint tests?
Scratches gonna scratch.
While I did my best to get things as durable as possible, if something really goes to town on the skins (like keys, or a large sheet of something getting swung around), they scratch. Also, where there is repetitive motion, whether from road vibration or repeated use (like opening/closing the shade), there’s really nothing you can do about the fact that the paint will scratch off. There is some solace in the fact that the products I used are readily available, so touch ups are relatively painless.
The next step would be 2 part epoxies and gel coats, but at this stage in the game, I’m not willing to go that far, and I’ll just stick with touching things up every once in a while.
After all these tests, and the incredible amount of time and cost it took to do the small bedroom area with rattle cans (it took north of 20 cans of consumer spray paint for that small area), I decided to give rolling regular house paint a try in the kitchen area. I cleaned all the vinyl coated interior skins with TSP-PF (the slightly more “earth friendly” version of TriSodium Phosphate) then rolled on a coat of Valspar Bonding Primer/Sealer and waited 48 hours for it to cure (probably overkill). I then rolled on two coats of Clark & Kensington Interior Satin Enamel.
After a couple days of letting the interior house paint cure, I would say the durability of the rolled on paint in the kitchen is far superior to the spray paint in the bedroom. You can still scratch it, but the house paint is able to heal a bit, whereas the spray paint is more brittle, and thus “breaks off” when scratched. The house paint also allows for the second rolled-on coat to scratch and reveal the first coat, where the spray paint all comes off at once. Looks like if I’m reusing interior skins that are c
overed in the factory vinyl, I’ll be rolling on paint from now on.
It just goes to show, that sometimes the easiest way actually IS the best way (not always, maybe not even often, but sometimes!).
Some links I perused ad referenced while doing the research for painting the interior skins: