Chuck,

Sounds like you're doing everything right, but I think maybe the problem lies in the Badger airbrush. First off, Badger isn't a real high-end brush... more of an entry level hobby brush. My Iwata is a $200+ artist's brush and still doesn't do "that great" with latex. For base/color coats you should use an automotive detail gun, like a Devilbis, Porter Cable, Binks, etc. They are designed to spray larger patterns with more paint flow, airbrushes are not. Airbrush nozzles are much smaller too, and tend to clog easily with latex paints. When you get the mixture and pressure so it will shoot well with an airbrush, sometimes it's not right for the surface you're painting it on.

Even with the right gun, it can be a tedious dance getting the perfect viscocity to your paint, air flow rate, paint flow rate and air pressure to make it happen. A lot of variables and combinations that have to hit simultaneously... You just develop a "feel" for it after time. Each paint and each gun has different characteristics, so it's hard to say exactly what you need to do. I'd stick with the WW fluid though, it helps a lot. I would shoot between 18 and 25 psi with a detail gun, but airbrushes may be different.

I've been airbrushing for over 20 years, but never with latex until now. Just getting started with the automotive detail guns too. So, you may want to enlist the help of some of the more experienced latex shooters here in the forum besides me. You really should consider spending the $50 and picking up a detail gun though, it will make the job much easier. Besides, they hold a lot more paint than the airbrush will, so you don't have to refill the gun as often.

Neo