Clear coating acrylic airbrush paints: Share your techniques

[Marc_G]

Hi folks,

In a thread on decal printing, a tangential question about clearcoating over Createx Auto Air / Wicked Colors came up. User kjkcolorado asked:

"I am also using Auto Air and Wicked Colors in my airbrush to paint rockets. If you don't mind me asking, what type of clear coat have you used with what kind of results?"

I thought it would be best to split that discussion off, and get input from others. To be specific, let's keep the focus to clear coating over mostly-water-based acrylic airbrush paints (be they Createx (inc. Wicked Colors, Auto Air, etc.), Badger, Americana, and so on).

My answer is:
My choice of clearcoat depends on my mood, the weather, the specifics of the project, and (I'm not joking) what day and time of day it is.

Overall, my favorite clear coat so far is Valspar High-Gloss Clear Lacquer, which I get from Lowes. It's Valspar product 65064. I like this clear lacquer because it is somewhat more blush-resistant than other clear gloss lacquers, and dries to a nice shiny gloss. I paint in often marginal humid weather. I try not to spray if RH is above 60%, but I can push it a bit. I've never seen any hint of reaction between the lacquer and the acrylic paint layer... I consider it completely safe. And, I've found even when it's 25 deg F out, I can spray this stuff and come back later and it has worked perfectly. So, year round clear coating is possible.

Here's an example of the results. Valspar gloss over white and red Wicked Colors:





I also use Duplicolor Paint Shop metallic clear... it works fine too. I'll have to find a pic of that.

Future works fine, though I've found in some cases it dissolves the acrylic ever so slightly, and can cause slight bleeding of darker colors over lighter colors. Thin coats, allowed to dry, seem to work fine. I avoid doing the "Future with Simple Green" super glossy trick over acrylics, because this mix definitely can melt the acrylic with smeary results.

Also I use Liquitex High Gloss Clear Varnish. This goes on wet and cloudy and dries to a beautiful shiny surface. However, it has poor self-leveling and if you get a run, it may show on the final product.

I'm out of time but will post more pictures in the coming days, to show examples of the work.

I invite everybody to add their experiences!

Marc

 

[Micromeister]

Marc:
Like using many Valspar products over the years but like most Lacquers Valspars contain no UV inhibitors. Might I suggest Rustoleum High-gloss marine Clear Spar Varnish as an alternative which have high levels of UV inhibitors for UV resistance in extreme weather. Works great through air brush or detail gun. Decent humidity tolerance and set-up time without the yellowing potential of clear lacquers.

Still like and use Krylon UV resistant clears on printed decals but not as a model clear coat, There Pledge with future is my first choice.

 

[H_Rocket]

To go over the Createx / Auto Air paints I use a two part polyurethane. I use the Finish1 available at NAPA (it is actually Martin Senour). I bought a $10 touch up gun from Harbor Freight to apply it. It is about the same cost as the rattle can stuff, however you do need a compressor...

I tend to use 3-4 coats with a 10 minute wait between coats for the flash.

You get a durable, hard finish that take a bunch of abuse.

 

[chrism]

For clear coats, I use Future for a gloss coat and I currently use Vallejo Model Air Clear Matt varnish for a flat clearcoat.

 

[Marc_G]

Marc:
Like using many Valspar products over the years but like most Lacquers Valspars contain no UV inhibitors. Might I suggest Rustoleum High-gloss marine Clear Spar Varnish as an alternative which have high levels of UV inhibitors for UV resistance in extreme weather. Works great through air brush or detail gun. Decent humidity tolerance and set-up time without the yellowing potential of clear lacquers.

Still like and use Krylon UV resistant clears on printed decals but not as a model clear coat, There Pledge with future is my first choice.

Interesting suggestion, that spar varnish. I had not heard of it before. I will check the usual places for it. Maybe I could spray it with a Preval sprayer? My airbrush setup is in the basement for indoor use. Im guessing the spar varnish is organic base?

I have also wanted to find that Krylon uv resistant clear... I have a bias against enamels but as a clear coat I can get over it and give it a whirl.

 

[Marc_G]

To go over the Createx / Auto Air paints I use a two part polyurethane. I use the Finish1 available at NAPA (it is actually Martin Senour). I bought a $10 touch up gun from Harbor Freight to apply it. It is about the same cost as the rattle can stuff, however you do need a compressor...

I tend to use 3-4 coats with a 10 minute wait between coats for the flash.

You get a durable, hard finish that take a bunch of abuse.

If I ever set up a spray gun for outside (garage) use I will look into it. Right now all my airbrushing is inside and I do rattle can clears in the garage or outside. My guess is a preval aerosol sprayer may not be a good choice for the polyurethane. And, does the material last in the sprayer for the 30 minutes or so or do you
Have to clean between coats due to polymerization?

 

[Marc_G]

Here are pics from my L'IL SMOKEY build over in LPR (Something a little Smokey).

View attachment 133587
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As noted in the build thread, I did a mist coat, a medium coat, then a wet coat of the Valspar high gloss clear lacquer. This result above is typical of the process.

Marc

 

[H_Rocket]

I mix up what I need for the total job and leave it in a Pyrex mixing cup for the entire time. It usually takes me 40 minutes and I never need to clean the gun between coats. Of course, I pay $7.50 (after the coupon) for the Harbor Freight touch up gun so if it gets bad -> in the trash it goes.

No, you don't want to use this stuff indoors. You MUST use a respirator.

 

[Marc_G]

Which Finish 1 do you use? One of the 7X0 series? Probably 710 or 730?

YEah, if I used this stuff a decent respirator is a must. Even for plain acrylics, a respirator makes sense, but this stuff looks super nasty. Don't want it in my lungs.

 

[Screaminhelo]

A good, general rule of thumb is to use a different type of paint for the clear coat than you used for the color coat. If you use lacquer for the color, use acrylic or enamel for the clear. A true acrylic can have an acrylic over coat (there's science involved in the explanation). There is a good thread that covers this and I'll post it if I can find it.

I personally usually use lacquer over most any finish. I just ensure that the. Color coat is fully cured first.

 

[hornet driver]

I've had really good success with most spray on clear coats--given I let the underlying paint dry--- The only one I've had any real issue with is valspar--it goes down great and drys wonderful, only problem was , I went back and taped a couple areas to weather--used blue tape---and it pulled the clear off. I was a bit surprised to say the least. Seems it does not bond well but it lays down really nice?? That said, I still use it as well as Krylon and Rusto. Rusto is my go to clear however,just gotta learn to be slow with it ! If I'm flat coating--dulcoat in the airbrush does the job.

 

[kenstarr]

I have done a bit with auto air. I always use the Duplicolor acrylic clear with a spray gun and compressor. I think I may switch to something (acrylic) from the farm implement store though. Can't remember the brand but you have to reduce it yourself and it's cheaper. Downside is it only come in a gallon can.
-Ken