Poor fluidisation is apparent as a slow and non-continuous transportation of the powder coating from the fluid container to the guns. Additionally, poorly fluidising powder will create volcano-like hills or rat-holes on the surface of the ‘fluid’ powder. When spraying, the powder cloud is inconsistent.
Fluidising air pressure is too low.
Adjust the pressure to achieve the correct fluidity, look for the fluidised powder surface to appear to gently simmer.
Compact or damp powder
Manually loosen powder in hopper, if humidity is the cause, leaving the box open to the atmosphere will normally correct the problem. In some circumstances it may be necessary to add a small amount of dry-flow aid to improve the coating’s fluidity. Check compressed air for moisture quality, it is vital that the air is clean and dry.
Fluidising plate clogged / defective
Clean or replace plate
Too many 'fines' in the powder coating
Decrease amount of reclaim to hopper. Check ratio of virgin powder
Powder dusting out of hopper and fluidised powder appears to be 'boiling'.
Fluidising air pressure is too high.
Reduce air pressure to fluid bed; properly fluidised powder will appear to gently simmer, not boil.