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My airbrush started occasionally "splattering" though I don't know if that's a good descriptor. In addition to blowing air and paint like normal, it will also spray out bigger drops of paint, so I'll get the smooth gradient that an airbrush gives and then there will be a couple of tiny, bright dots of color. Does that make sense?

Why is this happening and what can I do to fix it?

Sounds like your air pressure is too low or your paint mix is too thick or a combination of both.

You need to give more information to help diagnose the issue.

I have this problem anytime I thin paints with water in my airbrush.

As for paints, I use Vallejo Model Air.

As for pressure... this is harder to answer. I'm not actually sure what level I'm spraying at. I've got a compressor and a tank. When I turn on the compressor, it fills the tank and the gauge on the side stops at about 66 PSI. There's a sticker on the side of the compressor that says that it automatically turns on to keep the tank filled when it drops to 43 PSI.

Does that help? How can I tell what pressure I'm spraying at? The tank/compressor I have is the TCP Global TC-20T with a 3 liter tank.

Your compressor has a diaphragm regulator with a moisture trap. You have to look at the regulator on the leaving side of the compressor and turn the adjustment knob to the desired pressure, somewhere between 12 and 22 psi is fine for most work, assuming your paint is properly thinned.

If you don't know how to set your air pressure properly, I suggest you use Google to find articles on airbrush operation and check YouTube for instructional videos.

Well, I never set it when I bought it. But why would it start splattering all of a sudden, after many months?

Dillute with windex, not water, Problem solved

There is something wrong with your paint mixing then, it is probably too thick. The paint thickness doesn't have to be too far off to cause splattering. Your air pressure is probably way off from what it should be too.

Seriously, you need to learn the basics of airbrush operations. The air compressor and brush are no different than any other tool, you should always read the instructions before you use them. Not knowing what air pressure you are sending through the airbrush could potentially damage it.


Automatically Appended Next Post:

 Papaskittels wrote:
Dillute with windex, not water, Problem solved

Worst advice ever. Thin with a real thinning agent, whether it is name brand airbrush thinner (or medium) or a home made mix. Windex has chemicals in it that can be harmful to your health when inhaled and damaging to your equipment. Les Bursely of AwesomePaintJob has a video on his channel demonstrating how to make your own thinner if you don't want to buy a pre-made one.

http://youtu.be/GoKJUrISnTo

I'm not mixing paint - I'm using Vallejo Model Air, straight from the bottle, and have never used anything else. I was under the impression that those don't need to be thinned...?

You are correct vallejo model air are intended to be used straight from the bottle, some people choose to thin them anyway but not having experience with them I can't say 100% one way or the other.

Assuming the paint is being thinned correctly and it is a new problem then the only things I could think of are:

Bent needle tip, sometimes if it's just a subtle bend at the end the tip can start catching paint buildup which will occasionally get spattered off once it reaches a certain volume.

Loose needle, if the needle hasn't been pushed all the way forwards after cleaning there can be a slight gap allowing paint to flow along the needle even when you haven't got it drawn back which can lead to splatters every time you start spraying again after stopping.

Compressor pressure, though if you've not had this problem until now it seems unlikely, but if you have been spraying between 66 and 43 psi then you really need to turn that down it's way to high. To adjust the pressure on that tank turn the compressor on and begin spraying with the brush empty and fully open, then pop the outer ring of the pressure valve up (thats the black thing above the red circle just south of the pressure meter). Now turn it to the left until the needle is sitting on a psi of ~12-22 as previously mentioned by someone else whilst keeping the airflow through the brush, that will give you a correct psi when spraying instead of adjusting it without airflow.

I'll try and think of anything I've missed but if it's a recent problem it could well be that none of those solutions work either but fingers crossed eh!

I had some splattering recently (I use only VMA these days as well) and found that there was a little bit of residue from a previous job inside the end of the brush (Vallejo primer was the culprit). Did a full tear down and long careful clean and was fine after that.

 Tangent wrote:
I'm not mixing paint - I'm using Vallejo Model Air, straight from the bottle, and have never used anything else. I was under the impression that those don't need to be thinned...?

I would recommend thinning the VMA paints. I know they are "designed" for airbrushing straight from the bottle, they are still a little thick and can cause gunk up in the needle tip.

Well alright then! Thanks a ton! I'll give it a go here soon and let you guys know the results.

So, this past weekend I got a chance to play with the airbrush a bit. I hadn't run it through my sonic cleaner since the last time I used it, but I decided to put a few drops of paint in and try to spray. I also lowered my working pressure to about 18 psi.

I discovered that the splattering is happening when I have the airbrush fully open and spraying, and then I gradually release the paint flow on the trigger while keeping it pressed down so air is coming out still. So, I'll have it pressed down (air coming out) and the trigger pulled back all the way (maximum paint coming out), then I'll let the trigger come forward (so less and less paint is coming out while the trigger is still pressed down so air is coming out) and about halfway forward the paint will splatter out. I can repeat the process over and over with the same results - releasing the trigger forward causes the paint to splatter out.

Now, I think I had a partial clog, because no paint was spraying out when I had the trigger on full blast, so after this little experiment I disassembled the airbrush, ran it through the sonic cleaner a few times, and cleaned it out really good. I left it to dry overnight and will try again tonight.

I closely looked at the needle and saw no bend, but it's possible that there's some microscopic bend that I can't see.

every setup is unique and an airbrush is incredibly finicky. in general you have to work with it every time you try something new and even then going back to a known good configuration can cause you trouble. not kidding. i got a new needle and couldn't get the paint to come out right... after about 2 weeks of trying it over and over I realized I was overtightening the aircap. I had been airbrushing for a year plus at that point.

the results are definitely worth the hassle imo the amount of time you shave off basecoating and the ridiculous blending effects are worth it.

i bought something called golden airbrush medium, available at dickblick.com and that stuff will make almost anything sprayable.

I got a new Krome and just used it for the first time... same problem - paint splattering. This time, though, the paint constantly splatters out as the trigger is depressed as opposed to only splattering out when the trigger is released. In particular, this was happening much, much worse at about 20 PSI. When I cranked it up to 40 or so, just to see what would happen, it almost went away. I'm kind-of at my wits end, here.

this happens all the time. airbrushing is awesome until it totally screws everything up. the worst is when you AB metallics and end up getting tiny little metallic flakes all over everything.

tons of things can cause this:

-you didnt clean out the airbrush well enough. run tons of water through before you put paint through it.
-pressure is wrong
-your paint isnt thin enough or it could be too thin.
-paint dried on the AB tip
-type of paint plays biggest factor. some paint splatters way worse than others.
-type and quality of your airbrush.

test everything out BEFORE you airbrush the model. make sure to mask off the model if youre ABing a small detail! nothing worse than ruining a finished model.

Clean airbrush thoroughly. When thinning the paint, pre mix it in a container and swipe some paint up the side and when it flows freely back down the cup you are close to having the right consistency. With thinner paint reduce air pressure till it sprays smooth and even.

My vote for this would be bent needle tip. There are lots of other possible problems, but this sounds like the most likely issue.

It certainly does sound like admanaged needle/nozzle...considering that youve been playing with the paint viscosity and other bits with no joy.
Just to be sure you not still thinning with water are you? To get acrylics thin enough to spray with water you need to add so much water that the surface tension of the paint film is destroyed. Use an acrylic binder medium or a solvent (IPA?) if you cant get thin enough with the medium.
A bent needle might only bent by a fraction of a degree, this will make a huge difference, and using a bent needle will in turn damage the nozzle its supposed to sit flush with.
Symptoms of bent needles include many of the things you described; splattering of paint, spray skewing off to the side, no flow, poor flow, back flow...alsorts of issues can come of it.

Here is a question no one has asked you... Are you starting the flow of air before pulling the needle back to start the flow of paint? With your airbrush away from the model, you should push the trigger down to start the flow of air, then move to the model and ease back the trigger to start the flow of paint. When you have painted what you want, ease the trigger back to the neutral point and stop the flow of air... don't let it just snap back in to place.

Allso Paint can build up on the Nozzle guard of the airbrush. And sometimes flick a blob of paint at the model.

cerbrus2 wrote:
Allso Paint can build up on the Nozzle guard of the airbrush. And sometimes flick a blob of paint at the model.

Usually I would paint with the nozzle guard removed, This is what freehand airbrushes generally do. Thats where I learned about airbrushing before I applied it to mini's. I never got to the point of it causing droplets of paint splatter to happen, but it does reduce the quality of any line you want to draw with it. You just have to take care while the needle is exposed and remember to replace it when done. I hadn't considered this to cause the paint splatter because It doesn't come up for me personally... but its a very valid point.

Just a point of curiosity, have you looked on actual airbrushing forums for answers and help? They should be much more knowledgable on the subject that people here on a mini wargaming forum that may/may not use airbrushes compared to the airbrush specific forum that will generally contain only airbrushers.

I used to have this problem when I was using water to thin paints. Try a thinner medium

Thanks a TON for all the help, guys. I haven't posted in awhile because I was off work yesterday and had a chance to really go over my airbrush and try some of the things you guys have suggested.

Long-story-short, it was really simple. After I ran my airbrush through my sonic cleaner, fully disassembled and then reassembled, lubed everything up, and checked it out, everything was working fine. After a short time, it started happening again, so I got super thorough in trying to figure it out.

I discovered that little blobs of paint were building up on the needle guard, and were being "flicked" off when I pushed air through, resulting in the splatter effect.

I also started working with much lower PSIs, between 12 and 18, and it happens much less at these levels. Also, I noticed that it happens less often when I use shorter and shorter bursts of air and paint than I may have done in the past. Side note: I can't believe I ever used PSI above 25 or so. Sometimes now, even 12 seems like it's too high.

All that being said, I had this successful experience with a different pot of paint than I normally use. This time I was used a black primer (Vallejo Model Air) whereas before I was using the same pot of Grey Primer (also Vallejo Model Air). When it first started happening with the grey, I experimented with thinning and had the same splatter effect - this was with my old airbrush. With this new Krome, I had the splatter effect without thinning with the grey. When I figured out what was happening, I had switched to the black and had far fewer problems. I wasn't thinning the black, either.

Even after I fixed the issue with my Krome and figured out what was going on, I was still having issues with the grey. Not splattering, but now the unthinned grey seems to run as opposed to evenly covering the surface, in a way that the black doesn't do at all. Or blue. Or blue mixed with whites.

So, I'm starting to think that the grey might just be a bad pot. I'm not saying that being a bad pot would cause the splattering, but shouldn't the paint run more if it's thinned? Unthinned, I would think the paint would run less. Regardless, I want to prime with grey instead of black, so I've gotta figure this out, too.

I still don't know what's up with my old airbrush - it doesn't have a needle guard like the Krome so maybe the needle is bent even if it doesn't look like it is. Otherwise, that brush functions fine as far as I can tell.

As for the needle guard on the Krome, I don't think I can take it off. The nozzle doesn't screw in on the tip of the brush - it just seats into and over the needle where it comes out. Then, the final "cap" portion (which contains the needle guard on the outside) secures the nozzle in place when the cap is screwed on. The Krome came with another piece that looks like a different "cap" but without guard prongs, but it doesn't have screw threads so I don't know for sure how I'll be able to use it. It does seem to have a nozzle-sized hole right in the middle, though.

Oh, and yeah Scooty, there were times when I was pulling the trigger back first, and THEN depressing it to make paint come out. When I tested that out this time, it splattered almost every time. Needless-to-say, I don't do that anymore!