Hello. I’ve found that, when I airbrush I use a set pressure of 15 psi and try to thin enamels to the point that I get a a good covering mist it can’t be done. The problem I’ve been facing is that, when using white in particular, I can’t get it thinned quite right. It’s always too thin or thick at 15 psi-never just right. However, when I thin it to a somewat thick consistency AND increase the pressure the paint sprays and covers well. At a set 15 psi though, I should be able to get it to spray well by gradual thinning alone and not have to increase the pressure. My question is: How do you know when you should increase pressure or thin the paint more to get a covering mist?
Thru practice and experience,although there are some general rules,different paints and airbrushes have different characteristics which are learned rhru practice.Thats why many have practice models or use plastic spoons.
You seemed to have found the right combo thru your experimenting.
Each airbrush also adds its own variables to the airbrushing/thinning/air pressure equation, so what combination works well with one, may not work as well with another. Also as Tony mentioned above, certain colors have their own quirks as well. Yellows and Whites tend to require more adjustment efforts than say Blues, Reds, Grays, etc. It likely has something to do with the pigments if all else is the same. Keep at it and you’ll find your happy place in time.
Added to the above is also needle size.
Speaking for my own situation though, given what I have for airbrushes and the ones I use for enamel they turn on from about 25psi upward. Everything behaves better there, flow, spray pattern, leveling just everything. And that’s whether thinned 60/40 paint to thinner or 50/50. I save 15-20 psi for lacquer. If I spray washes ( rare) then even 10 psi.