Need some help a problem

Oh Boy!

      You have fallen into a hole I wouldn't wish on anyone. When You Primed how long was it before you put the topcoat on? The reason I ask is this. When I have primed with Rustoleum Dove grey primer nothing bad happened. BUT, if I painted the topcoat to soon(Within say six hours) this is what happened. I believe the primer hadn't completely gassed out where the tight spots were.Those would've been Micromillimeters thicker than the open flat spaces.

      How close to completion are you? Are you so close that there's too much stuff in the way? Because, you either have to wait and try mist coats later or strip and start over! Based on the photo, I would say that Mist coats later is what you're going to have to do.

Thanks T.B. I waited 24 hours after priming before the top coat. I'll try a couple of light coats and see how it looks.

Your problem is two-fold,  too thin and too high a pressure.  Ideally airbrush paint should dry on contact.   You puddled the paint on.  Don't believe this to be a primer outgassing problem

23 to 25 PSI is too high.  You probably need to be in the 12 to 15 range.

Scale Colors, while they include a mixing ball in the bottle, really need to be mixed well. Spend the time to do it well, shaking for a few moments often isn't enough  I have a vortex mixer and I really need to spend a good while getting Scale Colors to mix, pigments separate to the bottom.

Thanks, I'll try those changes too.

Hard to say difinitvely from photos but It looks to me as though the paint just wasn't fully mixed. The air pressure depends on paint viscosity, gravity or siphon feed airbrush, distance of the passes and speed of the passes. So a blanket statement of your pressure being too high may or may not be so. I often shoot acrylics at 25 psi with no issues. But you can find that out simply by a little test shooting before applying the paint to your model.

It looks like the paint is not wetting the primer.  It may be an incompatibility between primer and paint.

I'm not positive but it looks like the humidity might have been the issue. It was running at 70% r.h. I placed a dehumidifier in the room and got it down to 54%. I've painted 3 or 4 times since and no problems.