I wanted to use the Vallejo Glossy Black primer, and I knew I had no idea how to do it. So.. after a lot of practicing, I found out that a major issue, is glogging due to bits of paint, coming from the paint bottle. So, not an issue with the paint, but bits of paint in a really old bottle. Spraying with the paint from a new bottle worked nicely. I tried to clean out the gunk from the old bottle, but I had endless problems with clogging.

Also, it seems I have to thin the paint a little bit at least, but not too much.

Airbrushing on the glossy black primer at 30 psi worked ok, but I used my .35 airbrush, and not my 0.50 one. In any case it seems using my 0.35 airbrush works nicely as long as the paint is thinned enough.

So in the last week or so, I have finally learned to thin the damn paint enough, and now I should be able to airbrush on the glossy black primer without spluttering even. Some more investigation is required to figure out how little thinner I ought to use. Seems I can at least use 2 parts paint, 1 part thinner and no more than 10% flow enhancer.

I also suspect that with any clogging, there is too much air, compared to the flow of paint, perhaps making the paint dry quicker or something. It really is a big difference in the flow of paint in a functional airbrush, and a clogged one. :|

Some other things I've started doing:
1) Coat the airbrush cup with a thin layer of regdab
2) Clean the nozzle protector opening
3) After cleaning the self centering nozzle (Iwata Eclipse HP CS) gently tap the solid part against the table. I swear I saw something falling out of it the last time.
4) Instead of counting the drops of paint, I'll try to rely on the measuring lines in ml, in a tiny 10 ml glass cup.
5) I've also started to test paint colors on a small piece of white paper, to get to see what the paint looks like, shading wise.