Description of problem: 
    The sprayed paint dust particles land on the painted surface in the form of a powder.  

Causes:         

    – Spray gun is too far from the painted surface.
    – Spray pass is too quick.
    – Unsuitable thinner.
    – Very high air pressure.
    – Incorrect application viscosity.
    – Wrong spray gun setting.  Small nozzle with a large air cap.
    – Ambient air flow is disruptive.
    – Spray booth temperature is too high.

Preventive measures:

    – Use proper application technique.
    – Use appropriate thinner.
    – Use correct air pressure.
    – Use correct application viscosity according to the manufacturer’s specification.
    – Use slower thinner or add a retarder if it is too hot.
    – Use correct spray gun setup.
    – Avoid turbulence.

Remedy: 

    – Ground coats:          
    Remove with thinner or wait until dry and sand topcoats sand with P1200 and polish. 
    In the case of metallic monocoat finishes (600 series) you should sand and respray.