Trouble Shooting The Airbrush Most Common Problems and Causes When Airbrushing Colour Not Spraying or Restricted Clogged nozzle andor dirty needle; out of paint; needle chucking nut loose; paint too thick; improper air pressure; cracked or damaged nozzle; clogged needle cap or nozzle cap; vent hole in bottle lid clogged. Paint Bubbling in Cup Paint dried on needle; vent hole in bottle lid clogged; improper nozzle and body seal; cracked or damaged nozzle. Spray Pattern Skipping Paint sticking to needle tip; paint too thick; tip of nozzle is set back from tip of nozzle cap (tighten nozzle and cap); air enters screw section between nozzle and body (remove nozzle, clean screw section and refit). Spray Pattern Spattering or Spitting Paint sticking to tip of nozzle, needle or nozzle cap; bent needle tip; crack or damage to nozzle tip; clogged nozzle; atomizing air pressure too low; paint requires thinning.