Airbrushing PITA part 3

Tear down and clean the airbrush with Lacquer thinner and interdental brushes or something small designed to get in the airbrush. To get less overspay, Thin the paint more, lower the psi to under , get closer to the model. maybe 4-5 inches away and practice a lot.

Where the nozzle tip protrudes through the air cap make sure there is equal space all the way around the tip. This can get uneven as gaskets wear and parts don't sit perfectly square to the seats. Barring that I'd still suspect a spec of dirt someplace. I have a knock off Iwata that I have to use the next size up air cap for the .2 tip for this very reason you describe, the tip is not square in the cap so air get diminished on one side. While the next cap up gives equal space, it's also a wider gap, doesn't seem to bother a thing. I think if I ditched the gaskets all together and just waxed the seats and threads all would be fine.

I'm not alone on this theory, I think it's Don Weeler who mentions this problem at his airbrush review site as well. I don't recall if Sparmax is included but I do know it's the same tip and cap design basically.

You didn't drop the brush and ding the tip by chance ? That will do this too, as will a bent needle tip. And speaking of needles, I polish mine, makes a big difference in paint droplet uniformity and fine misting coats.