Actually, thinning latex with mineral spirits will cause seperation. Some guys will use Floquill or windshield washer fluid, but I have always used water. Water will not cause seperation as latex is a water based paint. I use American Traditions and Duron mostly as that is what my local Lowes carries. I usually wind up about 70 percent paint to 30 percent water and dont have any flow problems running at 25 to 30 psi on the airbrush.

Warren