AIRLESS SPRAY GUN TROUBLESHOOTING
DEFECTS
CAUSE
CORRECTION
Coarse spray
Low pressure
Increase the pressure.
Excessive fogging
High pressure
Reduce pressure for satisfactory pattern.
(overspray)
Material too thin
Use less thinner.
Pattern too wide
Spray angle too large
Use smaller spray angle tip.
Pattern too narrow
Spray angle too small
Use larger spray angle tip. (If coverage is OK,
try tip in same nozzle group)
Too much material
Nozzle too large
Use next smaller nozzle.
Material too thin
Pressure too high
Reduce pressure.
Too little material
Nozzle too small
Use next larger nozzle.
Material too thick
Thin distribution in
Worn tip
Change for new tip.
center of pattern
Wrong tip
Use nozzle with a narrow spray angle.
"horns"
Thick skin on work
Material too viscous
Thin cautiously.
Application too heavy
Reduce pressure and/or use tip in next
larger nozzle group.
Coating fails to
Material too viscous
Thin cautiously.
close & smooth over
Spray pattern irregular,
Orifice clogged
Clean carefully.
deflected
Tip damaged
Replace with new tip.
Craters or pock
Solvent balance
Use 1 to 3% "short" solvents remainder "long"
marks, bubbles
solvents. (Most likely to happen with material of
on work
low viscosity, lacquers etc.).
Clogged screens
Debris in paint
Clean screen.
Coarse paint pigments
Use coarse gun filter screen.
Incompatible paint
Use coarser screen for larger orifice tips.
mixture & thinners.
If thinner was added, test to see if a drop
on top of paint mixes or flattens out on
the surface. If not, try different thinner in
fresh batch of paint.
TEST THE PATTERN
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