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I recently started airbrushing WH40K and have been having an issue that I've been unable to solve.

Basically, after a while (sometimes an hour, sometimes minutes) the airbrush will start to sputter out very wet paint, almost like water or raw medium with traces of pigment in it. The brush makes a sputtering sound and the paint splatters all over whatever I'm pointing at. If I continue to spray air on the splatter, it will blow away the paint very easily. It also can be wiped up with a towel or cotton swab fairly easily.

I am using vallejo surface primers and have had this issue arise after about 45 minutes.

Then I am using Citadel Air paints from the pot and am having this same issue quite quicker.

I have tried a couple of things already.

One, cleaning the airbrush. I have flushed Grex Airbrush Cleaner through it, as well as some distilled water until it no longer blows any liquid out.

I have also cleaned the needle tip and the entire needle.

This usually solves the problem for a few bursts of painting, but then it quickly comes back.

I have tried using Vallejo airbrush thinner and flow improver but have not noticed any difference in performance.

Another noted issue is the airbrush will create bubbles around the nozzle. Is this an indication of the seal going bad?


I am using a Grex Genesis XGi airbrush and compressor set to 20psi and a 0.3mm needle.

Thanks for your time and help!

Does your compressor have a tank and moisture trap?

 Luciferian wrote:
Does your compressor have a tank and moisture trap?

Moisture trap yes, tank I'm not certain. It fills up to whatever PSI I set it to and then turns on when the PSI dips below that setting.

So to have it spray 20psi, I blow air out and set it to 20, so that when it's idle its up around 30 or 40psi.

I'm no expert as I only just got an airbrush myself, but mine will spray out pure water at the beginning of every burst of air after I use it for a while. My compressor is tankless and I think condensation is building up in the line. I have a moisture trap in the compressor but not on the other end of the air line.

It's not constant, though; all I have to do is blast some air through to spray it out before I start painting with it.

You do not have an air tank, the compressor is filling your lines with air to the set PSI and then backfills as you use it. I have the same setup, have for years now, you don't really NEED a tank

What you DO need is an in-line moisture trap, the one connected to your compressor is not enough. It gets hot and stops working as you work, so water is coming through your air line and sputtering out. I had the exact same issue and an in-line moisture trap solved it completely. They aren't even expensive, although the cheap ones I use tend to crack and leak every few months and need replacement. They still work, they just leak and make your compressor work harder than it should

http://www.ebay.com/itm/1-8-Airbrush-In-Line-Mini-Air-Filter-Moisture-Filter-Water-Trap-Spray-EB-/372079374906?hash=item56a1a8b23a:g:d3wAAOSwHqRZv5Ft

 Kalamadea wrote:
You do not have an air tank, the compressor is filling your lines with air to the set PSI and then backfills as you use it. I have the same setup, have for years now, you don't really NEED a tank

What you DO need is an in-line moisture trap, the one connected to your compressor is not enough. It gets hot and stops working as you work, so water is coming through your air line and sputtering out. I had the exact same issue and an in-line moisture trap solved it completely. They aren't even expensive, although the cheap ones I use tend to crack and leak every few months and need replacement. They still work, they just leak and make your compressor work harder than it should

http://www.ebay.com/itm/1-8-Airbrush-In-Line-Mini-Air-Filter-Moisture-Filter-Water-Trap-Spray-EB-/372079374906?hash=item56a1a8b23a:g:d3wAAOSwHqRZv5Ft

Yeah, the moisture trap I have is only on the compressor side. I hadn't thought about having one on the other end of the line, but that totally makes sense. I'll find a good brand and give it a try right away.

Thanks!

Even with a moisture trap, a compressor with a tank you must blow out your tank after every use. Otherwise, condensation moisture just accumulates in the tank and not only sputters out, but it will rust your tank.

If your compressor has a tank, you will know, as it will be a sizeable item (could be 1/2 gallon or so) and should have a valve at the bottom. Open it (usually by unscrewing) when the tank pressure is below 40 psi and let the rest of the air blow out the moisture. Keep this valve open and when you get ready to fire it up again, just be sure to close it before you turn it on. After a few times, this process will become second nature.

Tankless compressors can eliminate any moisture problems with a moisture trap connected to your hose as close to the airbrush end as possible.