Airbrush issues

I am brand new to airbrush was trying to get a feel for a it on an old kit I butchered when I was young. The paint seemed to come out almost dusty/grainy leaving a spotted finish. The airbrush is a paasche vl. I am not sure what I am doing wrong or what this is a symptom of

@Mead93 Your paint is starting to dry before it hits the surface of the model. Could be a couple of fixes.

  1. Thin your paint more.
  2. Move your airbrush closer to the model.
    Be sure to strain the paint before use. Good luck.
    Stay safe and take care friends,
    Don “Lakota”
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There are a lot of variables, what air pressure? Paint? What brand? Relative temperature, humidity. Spray distance. Can you give details?
I see in your picture that the turret has been decaled, so are you trying to do a post shade?

I am just practicing on an old crapy kit. PSI was 15 with a 1:1 mix of Tamiya paint and acrylic thinner. It’s quite dry where I am around 35% humidity

I was spraying from about 3 inches away during this test.

The last time my paint job ended up looking like that I didn’t strain my paint and I had a needle that was a little bent. A double whammy.

Was it Tamiya thinner? When I thin Tamiya paints, I go 40/60 ratio and spray closer to the surface.

Yes it was, Tamiya X20A acrylic thinner. 40% paint I assume? I’ll give more thinner and closer to the model a try.

I had another, probably stupid, question about dual action airbrushes. Am I right in thinking air output is controlled at the compressor? Meaning you should fully depress the trigger for air and then adjust paint by pulling the trigger back. Or should I also be using the trigger to fine tune air flow?

Yes, 40% paint. You can control the air and the paint flow with the trigger. It takes practice. You’ll get a feel for it after a while. One suggestion I’ve heard it to practice with water on paper.

Cheers! I’ll give the thinner mix a try. I’ve been practicing a bit on paper with basically ink (heavily thinned paint) to get a feel for how the brush handles. I also have some old kits to practice on as well

You can also try adding a few drops of Tamiya retarder to your
paint /thinner mix seeing that you are at 35% humidity which is
quite dry and could be causing the problem.

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Thanks for the help everyone! Increased my thinner and lowered my psi a tad. Going on smoother now, I think I over thinned now as it splatters a bit so looks like it’s just a matter of dialing my thinner ratio in

Soak the old kit in some Simple Green for about an hour and the old paint will come off if it is acrylic, leaving a smooth surface for you to practice on.

Cheers! I’ll give that a try.

I once tried that in undiluted Simple Green and it started dissolving the styrene.

One problem that I’ve noticed a lot of beginning air-brushers have with dual action AB’s is that they don’t use the proper trigger control technique.

Always press down first to open the air, THEN pull back on the trigger to open the paint.

Stopping is the exact reverse. Push forward on the trigger to close the paint flow, THEN lift off the trigger to stop the air.

Many folks have problem with the STOPPING sequence. They “ride” the trigger and lift off the air before they close the paint. This allows a drop of paint to pool at the AB tip, so as soon as they press down on the trigger to start the air for their next pass, they get spatters from the drop of paint on the tip (which will not atomize / aerosolize from the droplet form).

Another cause for spatters is the same sort of effect caused by too much paint flow and / or too thick viscosity with not enough air flow or pressure. The paint is not finely atomizing or aerosolizing because there is not enough air pressure for the volume of paint or its viscosity.

Note that air flow is a factor of BOTH the volume of the air AND the pressure, so you can have high pressure and not enough volume or high volume with not enough pressure. Both of these air factors have to match BOTH the paint volume AND the paint viscosity factors.

For a beginner, it’s usually best practice to adjust the air pressure on the regulator, set the trigger movement (needle control / max paint volume) using the adjusting nut, then learn to press down all the way on the trigger and THEN pull all the way back. Modulate the thickness of the line by moving the trigger backwards or forwards while maintaining full downward pressure for max air volume at the pressure set on the regulator.

Only after the DOWN-BACK-FORWARD-UP trigger operation becomes habit should you start to experiment with trying to modulate the air volume by not pressing the trigger down all the way. This can be done, but it can also lead to poor trigger control habits if those are not ingrained first.

However, in ALL cases: AIR ON FIRST, paint on then off, then AIR OFF LAST.


Also be sure to check your equipment. I used some crappy airbrushes in the past and it always clogged and I ended up throwing it away. It may be causing your paint to come out unevenly. If you are going to invest in this hobby I believe it is worth having the best airbrush (for a fair amount of money of course – after all this is just a hobby for me). Anyway, hope this is even just a little helpful. I am still learning all the time too!

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The paasche VL I have came highly recommend for a beginner. I thought I would get it for $80 with the kit and if I really got into airbrushing I’ll eventually work my way up to an Iwata. I am fairly sure this was a thinning issue. As the primer I bought that was supposed to be applied straight from the bottle went on smooth.

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You should be able to do a lot with the Pasche. I start with a new air brush by spraying lines and patterns on an old pad of watercolor paper.
I also spray on the pad any new mixed colors I’m using and write notes about the brand, color, and ratio. A word of caution if you do this, the colors don’t always look like an exact match for what’s going on the model. But, it’s close enough for me.
Take care and stay safe friends,
Don “Lakota”

Another couple of suggestions, you may need to clean the kit with alcohol or soap in case there is any grease that difficult paint adhesion.

And do not pull the trigger full back, start slowly so you airbrush a mist of paint, do not try to cover it all at once. Colour should be built up layer by layer.

The Paasche VL is good, reliable kit. It’s been around for a long time and, as a design, is very mature. At one time, it was considered about the best airbrush available for modeling.

Just be careful screwing the handle back onto the body if you remove it for cleaning or adjusting the needle travel. It has fine threads that are easy to cross thread. However, replacement parts are readily available and relatively inexpensive. Paasche offers an all-metal replacement handle that has an oval hole in that allows the needle travel to be adjusted without having to remove and replace the handle.

Anyways, the Pasche VL will get you where you want to go. No real need to even consider another AB until you can get every bit of performance from the VL (which is quite a lot). For decades, the VL was the leader in airbrushes for hobbyists. Many, many tens of thousands of world class models have been painted using one. Because replacement parts are so readily available, it’s a really good AB to learn on, too. If you break or damage something, you can get back in business quickly and inexpensively.

Its only real downside is that it’s a bottom feed AB. If you add a Paasche 1/4 oz VL side cup (P/N VL-1/4-OZ) you’ll be able to mix and spray much smaller quantities of paint versus having to use the screw lid paint jars. (Maybe you AB kit came with one?)

I think by the time I really learned to use my old single action Badger 200 back in the '70s, I had pretty much replaced every part on it except the body. I don’t think in all the years since I’ve learned much else about airbrush mechanics. And, BTW, at that time, the Paasche VL was considered about the best airbrush that you could buy… waaay too expensive for me to afford one. No reason for you to not get an equally good education from your VL.

Use and enjoy it. You should gets years and years of good airbrushing from it.