Spray Gun Troubleshooting - AIRLESSCO LP460 Service & Operation Manual

AIRLESS SPRAY GUN TROUBLESHOOTING
DEFECTS
Coarse spray
Excessive fogging
(overspray)
Pattern too wide
Pattern too narrow
Too much material
Too little material
Thin distribution in
center of pattern
"horns"
Thick skin on work
Coating fails to
close & smooth over
Spray pattern irregular,
deflected
Craters or pock marks
Bubbles on work
Clogged screens
TEST THE PATTERN
12
CAUSE
Low pressure
High pressure
Material too thin
Spray angle too large
Spray angle too small
Tip size too large
Material too thin
Pressure too high
Tip size too small
Material too thick
Worn tip
Wrong tip
Material too viscous
Application too heavy
Material too viscous
Orifice clogged
Tip damaged
Solvent balance
Contamination or dust
Extraneous material
in paint.
Coarse pigments
Poorly milled pigments
(paint pigments glocculate
cover screen. Incompatible
paint mixture & thinners.
CORRECTION
Increase the pressure
Reduce pressure for satisfactory pattern
Use less thinner
Use smaller spray angle tip
Use larger spray angle tip. (If coverage is OK,
try tip in same nozzle group)
Use next smaller tip
Reduce pressure
Use next larger tip
Change for new tip
Use tip with a smaller spray angle
Thin material
Reduce pressure and/or use smaller tip
Thin material
Clean carefully
Replace with new tip
Use 1-3% "short" solvents remainder "long" solvents.
(This is most likely to happen with material of low
viscosity, lacquers etc.)
Clean surface to be sprayed
Clean screen
Use coarse screen if orifice size allows
Use coarser screen, larger orifice tips. Obain ball
milled paint. If thinner was added, test to see if a
drop on top of paint mixes or flattens out on the
on the surface. If not, try different thinner in fresh
batch of paint.