Am I Using the right airbrush?

[Dr Fly]

So i am a bad workman, and i want to blame my tools.

Coming back to racing after a bit of an absence and just finished airbrushing a shell (I am no artist, i mostly do it for the DIY satisfaction). It was my first time using both water based paints and liquid mask. The liquid mask went really well and I was really happy with the results (I always used to suffer with bleeding lines).

The paint however, was a completely different story. The airbrush was coughing, spluttering, clogging and generally doing everything it could to make painting a real pain.

So i am going to throw it open to you guys to tell me where i am going wrong.

Airbrush: Aztek A470
Paint: Faskolour
PSI: 20-50

I am a bit worried that the brush may be gunked up inside, with the old horrible paint. But i really dont want to buy another airbrush right now. I can get new nozzles for it, but again, don't want to throw good money after bad.

The paint itself seems pretty thick compared to the old paint i used to use. Are other airbrushes better suited to this paint? ANybody out there using this airbrush?

I appreciate any help!!