TROUBLESHOOTING
TROUBLESHOOTING (CONTINUED)
Problem Encountered
Possible Cause
Corrective Action
Heavy top or bottom pattern.
Horn holes plugged.
Clean. Ream with non-metallic point.
Obstruction on top or bottom of fluid tip.
Clean.
Cap and/or tip seat dirty.
Clean.
Heavy right or left side
pattern.
Air Cap holes plugged.
Clean Ream with non-metallic point.
Air cap loose or dirty seat.
Clean and tighten.
Dried material on fluid tip.
Use a nonmetallic point
to clean Air Cap.
Heavy center pattern.
Fluid pressure too high for atomization air
(pressure feed).
Balance air and fluid pressure.
Material flow exceeds air cap’s capacity.
Increase spray pattern width with spreader
adjustment valve.
Thin or lower fluid flow.
Spreader adjustment valve set too low.
Adjust.
Increase pressure.
Material too thick.
Thin to proper consistency.
Split spray pattern.
Atomization air pressure too high.
Reduce at regulator or gun.
Fluid pressure too low (pressure feed only).
Increase fluid pressure
(increases gun handling speed).
Pattern Control Knob too wide open.
Adjust.
Spitting or pulsating spray.
May also be accompanied
bybubbling in the paint cup.
Loose or damaged fluid tip/seat.
Tighten or replace.
Material level too low.
Refill.
Container tipped too far.
Hold more upright.
Obstruction in fluid passage.
Back flush with solvent.
Loose or broken fluid tube or
fluid inlet nipple.
Tighten or replace.
Dry, loose or worn needle packing.
Replace packing.
Unable to get round spray.
Spreader adjustment screw not
seating properly.
Clean or replace.
Air cap retaining ring loose.
Tighten.
Will not spray.
No air pressure at gun.
Check air supply and air lines.
Internal mix or pressure feed air cap and
tip used with suction feed.
Change to proper suction feed air cap
and tip.
Fluid pressure too low with internal mix cap
and pressure tank.
Increase fluid pressure at tank.
Fluid needle adjusting screw not open
enough.
Open fluid needle adjusting screw.
Fluid tool heavy for suction feed.
Thin material or change to pressure feed.
Starved spray pattern.
Inadequate material flow.
Back fluid adjusting screw out to first
thread or increase fluid pressure at tank.
Too much atomization air pressure.
Reduce pressure.
Problem Encountered
Possible Cause
Corrective Action
Excessive overspray
Gun too far from work surface.
Adjust to proper distance.
Improper stroking (arcing, gun motion too
fast).
Move at moderate pace, parallel to
work surface.
Excessive fog
Too much, or too fast-drying thinner.
Remix properly.
Too much atomization air pressure.
Reduce pressure.
Dry spray
Air pressure too high.
Reduce air pressure.
Gun tip too far from work surface.
Adjust to proper distance.
Gun motion too fast.
Slow down.
Gun out of adjustment.
Adjust.
Fluid leaking from packing
nut
Packing nut loose.
Tighten, do not bind needle.
Packing worn or dry.
Replace or lubricate.
Fluid leaking or dripping from
front of pressure feed gun
Packing nut too tight.
Adjust.
Dry packing.
Lubricate.
Fluid tip or needle worn or damaged.
Replace tip.
Foreign matter in tip.
Clean.
Fluid needle spring broken.
Replace.
Wrong size needle or tip.
Replace.
Runs and sags
Too much material flow.
Adjust gun or reduce fluid pressure.
Material too thin.
Mix properly or apply light coats.
Gun tilted on an angle, or gun motion
too slow.
Hold gun at right angle to work and adapt
to proper gun technique.
Thin, sandy coarse finish
drying before it flows out
Gun too far from surface.
Check distance. Normally about 8”.
Too much air pressure.
Reduce pressure and check spray pattern.
Improper thinner being used.
Follow paint manufacturer’s mixing
instructions.
Thick, dimpled finish
“orange peel”
Gun too close to surface.
Check distance. Normally about 8”.
Too much material coarsely atomized.
Increase air pressure or reduce
fluid pressure.
Air pressure too low.
Increase air pressure or reduce
fluid pressure.
Improper thinner being used.
Follow paint manufacturer’s
mixing instructions.
Material not properly mixed.
Follow paint manufacturer’s instructions.
Surface rough, oily, dirty.
Properly clean and prepare surface.
