Airbrush paint flow stops

I went back and mixed up some flat black acrylic (Testors), set up a big piece of plastic along with a piece of Expedex 80# paper. Then I fired everything up and went though a bunch of excercises, loops, half moons, dots, etc. I kept checking for tip build up and there it was, a little crust on the needle. I gently rubbed the end in a paper towel I dipped in cleaner and it cleared up and I kept on working with no problems. But, when I went to clean it, by putting the nozzle of the bottle of cleaner in the siphon tube (airbrush, not cap), I had leakage around the aircap.

I ran some enamel through (Boyds gloss white # 1145, 2:1) and had zero problems. I flipped around the cap guard and was able to get a real tight paintline. But later I reassembled it after cleaning and drying, then ran just some water through using an unused cap and bottle. It worked intermittantly, with a lot of spitting. I got the best results after I stopped and waited for the compressor to cycle back up. It blasted out fine (mashed down and all the way back) then tapered off over and over. No leakage I could find and it looked like it was siphoning fine. Could this be from there isn't enough viscousity in the water, so it was too thin?

Also, is there a manual out there somewhere for the 3000? I figured out that the needle tube is adjustable and I think I have it set to a good spot, but I think I'm missing something. The O ring looks to be in good shape and I'll try the wax trick later.

Oh yeah, here's what I'm working on: http://godlesscommies.blogspot.com/

"Dry-Tip" is usually more of a problem with acrylics. Try thinning your paint more and/or lowering your air pressure. If that doesn't work, keep a moist q-tip, cotton ball or rag near by. (use your favorite/appropriate thinner) You can dab the tip every now and then to clean it out. I use a q-tip thats sitting in a small jar of thinner. Just be careful with the needle tip (keep it retracted when cleaning) and be mindful of any "lint". Let us know if it helps!

I've been modeling for a while and I've found that airbrushing is 10% airbrush and 90% modeller. Don't get discouraged and don't give up on the AB. You'll find the double action better for control, but you will have to get used to it. Practice, practice, practice.

And always feel free to post if you are having difficulties.

Does it stop and then all the sudden start again or does it just stop?

Internal mix airbrush's (like your Omni) has to pull a proper vacumn to work properly. You probably have a bad seal somewhere. You can replace the o-rings or you can do what I do. Put a little beeswax or non-hardening gasket sealer on the threads of the tip pieces. I prefer non-hardening gasket sealer because its solvent resistant but still has to be replaced every 10 or so sessions. Wax sometimes doesn't last a whole session. The gasket stuff I use is Permatex form a gasket sealant #2 - 1.5 oz tube from the autoparts store. Use at your own risk but I attest that it works well for me anyway.

That might be it. I am a n00b with airbrushes, but I started out with a Badger 200NH about 3 months ago and found out quick that it didn't do everything I wanted. Mind, it's a good brush, but the 3000 looked better.

I don't think what you're describing is possible...If the brush is still siphoning then the paint has got to go somewhere. I think you might be suffering from dry-tip. The brush might be squeaky clean, but if just a small amount of paint dries up at the very tip, it will clog. Could this be it?