Troubleshooting
3A1183C
23
Airless Spray Gun
Problem
Cause
Solution
Coarse spray
Low pressure
Increase the pressure
Excessive fogging (overspray)
High pressure
Reduce the pressure to satisfactory pattern
distribution.
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 tip group)
Too much material
Nozzle too large
Use smaller tip
Material too thin
Use smaller tip
Pressure too high
Reduce pressure
Too little material
Nozzle too small
Use next larger tip
Material too thick
Thin distribution in center of
pattern “horns”
Worn tip
Change to new tip
Wrong tip
Use nozzle with narrow spray angle
Thick skin on work
Material too viscous
Thin cautiously
Application too heavy
Reduce pressure and/or use tip in next
smaller tip size
Coating fails to close and
smooth over
Material too viscous
Thin cautiously
Spray pattern irregular,
deflected
Orifice clogged
Clean carefully
Tip damaged
Replace with new tip
Craters or pock marks, bub-
bles on work
Solvent balance
Use 1 to 3% “short solvents remainder “long”
solvents (this is most likely to happen with
material of low viscosity, lacquers, etc.)
Clogged screens
Extraneous material in paint
Clean screen
Course pigments
Use coarse screen if orifice size allows.
Poorly milled pigments (paint
pigments glocculate)
Use courser screen, larger orifice tips. Obtain
ball milled paint. If thinner had been added,
test to see if a cover screen. Incompatible
drop placed on top of paint mixes or flattens
out on the paint mixture and thinners on the
surface. If not, try different thinner in fresh
batch of paint.
Excess paint builds on tip
guard
Spray gun too close to surface
Hold gun further from surface sprayed
Pressure setting too high
Reduce pressure setting
Drips, spits from tip
Valve seat and/or ball in gun
head damaged or worn
Service spray gun, replace valve assembly
