Airbrush was working great, and then not...what did I do wrong?



I'm really hoping this forum can help me. I have a Grex GXi, double-action, gravity feed airbrush with a 0.3mm nozzle. I'm a novice when it comes to airbrushing and but when I used the Grex at a demonstration I thought, "this is going to be perfect". I'm painting tabletop miniatures (Warhammer) so I really wanted something that I could use at low pressure, 10-15psi, and for really fine detail, hence the 0.3mm nozzle. I got the airbrush home and didn't have a lot of success, but then all of sudden it started working. I don't know what I did, but it just clicked. I was using Vallejo acrylics mixed with Createx airbrush medium and was airbrushing like a pro. Paint was shooting at low pressure without sputters and I was flushing and then changing colors and it was all going great. At some point after many hours, it started to fail. Paint was coming out in sputters and I couldn't get back the control I had before. I cleaned the airbrush with airbrush cleaner and then in an ultrasonic cleaner. I took it apart multiple times, tried using different paints, both Vallejo air and then Createx air colors, and still nothing. Finally, through this forum (thank you, btw) I found the trick to tighten the nozzle. Did that and still nothing. I finally talked to Grex support (who are fantastic, btw) who first walked me through the tightening of the nozzle and then suggest I send the airbrush to them for an inspection. Fortunately they are local here in SoCal, so it was not a problem. They explained I had a very dirty nozzle and then thoroughly cleaned the airbrush and sent it back. Again, I feel like they have been so terrific in helping me solve this problem. Today was the day I finally got back to painting. I took out the airbrush, shot some water through it and started painting. I thought I should start with "air-ready" colors just to be sure. They worked alright (not perfect) but I thought, "let me see if I can work through it". I got my model and arranged my colors and starting painting. Again, nothing was working. The airbrush should have been in tip-top condition have just come back from the manufacturer, so it's got to be something I'm doing.

I'm hoping this forum can point me in the right direction. I know airbrushes can be finicky, but when I had those two great days of painting I also know that they can work--and really work well. I'm hoping there's some minor, obscure part of the process that I'm not doing right that I can correct. Maybe the air hose isn't connected well enough? or the compressor isn't working right? Or another point I'm overlooking. And if it's the paint, please (PLEASE) tell me what I should be doing. I've seen so many youtube videos that tell you can shoot anything as long as you mix it with windex or airbrush medium. And having proved my paints could work, I was convinced I didn't need to go and invest in an entire new range of paints.

I really appreciate anybody's help.

welcome to waterbased paints lol.this is why I use urethane. Since they said it was very dirty then it's a paint/cleaning issue. That stuff likes to settle and dry up in the airbrush very easily.

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What immortal said. If your using acrylics ...especially water based... you'll learn eventually that you'll have to over reduce with water to keep it from becoming an issue sprayin. I used Apple Barrel in mine and had to use only 1 or 2 drops of the paint to a full gravity feed cup of water to be able to continuously spray with little tip dry.
Another word of caution is that the paint likes building up in the needle caps....and along the needle itself between the cup and seals. If your figurines are along the metallic lines you can try the popular ones people here's late I cant remember them... just look up any of the WIP's dealing with motorcycles and cars.
Ceramic types.... over reduce and stay vigilant. Higher pressure is needed also. With the Apple barrel acrylic craft paints.... over reduced ungodly amounts and higher pressure you can still get a very thin line....think veins in an eyeball.
We seem to back to that 200-1 reduction LOL..Soz Suthern, running joke ;)..Though two drops too a full cup, I'm gonna buy me some of that paint..Sounds awesome LOL..

Windex no doubt works for some, glycerin for others, me I just use good ol water, reduce it right, strain the paint then load it into your gun, test spray, adjust either pressure to suit or add a little more water if your pressure is already around the 30 PSI mark..One of the keys to tip dry or dirty guns and how to avoid it is not to stop too long between strokes..Its funny that I dont see this mentioned often but some people over use their air at the end of the stroke (IE After they have shut of the ink) and that constant air naturally dries the paint withing the nozzle and on the tip ....Ya want to shut it off pretty darn fast to avoid it drying the paint, keep the paint on the needle and nozzle wet and the problem will probably reduce a lot same as in between your strokes, dont linger too long and keep moving on the stroke needs..Outside temps can also make a diff, ie on a hot day you may get more tip dry or gunk buildup..

Also another thing you rarely see mentioned but is no doubt for most a pretty normal thing they do is to point away from your work and blast some paint through at a full pull back of ya trigger, this helps dislodge and rewets any potential issues..Hope that helps a little..Try that before worrying too much about cleaniness..Another thing I don't tell peeps often is I just really cant be bothered cleaning my brush, it will do hrs on hrs of work before I'd bother even flushing some clean water thru but thats my laziness, not saying its a good thing but I really think some over worry about cleanliness and not other things that can cause similar issues..Worth a try maybe and good luck..
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