Thanks for the feedback. I've checked my set up in relation to your thoughts.
I've been using Vallejo paints with no success. Until now!! I have finally been able to get a clean prime coat down on some models!!! yippee
I may have got a little too carried away and sprayed too much on for a base coat. But I'm still learning.
With the Vallejo Air, I didn't add anything else. With some GW paints, I added some thinner to 1:1 but that didn't work too well. But that's probably because the GW paints I have are close to 10 years old.
My pump will only go to 20psi when I'm actually spraying. Should I get a tank to try and keep the psi higher, or do I need a tank that will go to a higher psi?
If anyone has any other suggestions I'm all ears.