Troubleshooting Possible Problems
in Operation
CONDITION
CAUSE
Heavy top or
Horn holes plugged.
bottom pattern
Obstruction on top or bottom
of fluid nozzle.
Cap and/or nozzle seat dirty.
Heavy right
Left or right side horn holes plugged.
or left side
Dirt on left or right side of
pattern
fluid nozzle.
Remedies for the top-heavy, bottom-heavy, right-heavy, and left-heavy patterns:
1. Determine if the obstruction is on the air cap or the fluid nozzle. Do this by making a test spray pattern.
Then, rotate the cap one-half turn and spray another pattern. If the defect is inverted, obstruction is on the
air cap. Clean the air cap as previously instructed. Also check for dried paint just inside the cap center hole
opening; remove by washing with solvent.
2. If the defect is not inverted, it is on the fluid nozzle. Clean nozzle. Check for a fine burr on the edge of the
fluid nozzle. Remove with #600 wet or dry sandpaper.
Heavy centre
Spreader adjustment valve set
pattern
too low.
Atomising pressure too low.
Material too thick.
Split spray pattern
Atomisation air pressure too high.
Fluid adjusting knob turned in
too far.
Spreader adjusting valve set too high.
Jerky or fluttering spray
*Loose or damaged fluid nozzle/seat.
Loose or broken cup fluid nipple.
Material level too low.
Container tipped too far.
Obstruction in fluid passage.
Loose fluid needle packing nut.
Damaged fluid needle packing.
Unable to get round spray
Spreader valve not seating properly.
Air cap retaining ring loose.
Will not spray
No air pressure at gun.
Fluid adjusting knob not
open enough.
Fluid too heavy for gravity feed.
Paint bubbles in cup
Fluid nozzle not tight.
Fluid leaking or dripping
Cup lid loose.
from cup lid
Dirty cup or lid.
Cracked cup or lid.
Starved spray pattern
Inadequate material flow.
Low atomisation air pressure.
Excessive overspray
Too much atomisation air pressure.
Gun too far from work surface.
Improper stroking (arcing, gun motion
too fast).
Excessive fog
Too much or too-fast-drying thinner.
Too much atomisation air pressure.
Dry spray
Air pressure too high.
Gun too far from work surface.
Gun motion too fast.
Gun out of adjustment.
Fluid leaking from
Packing nut loose.
packing nut
Packing worn.
*Most common problem.
CORRECTION
Clean. Ream with non-metallic point.
Clean.
Clean
Clean. Ream with non-metallic point.
Clean.
Turn out counter clockwise to achieve
proper pattern.
Increase pressure.
Thin to proper consistency.
Reduce at regulator or gun handle.
Turn out counter clockwise to achieve
proper pattern.
Turn in clockwise to achieve proper
pattern.
Tighten or replace.
Tighten or replace cup.
Refill.
Hold more upright.
Back flush with solvent.
Tighten.
Replace.
Clean or replace.
Tighten.
Check air supply and air lines, blow out
gun air passages.
Turn out counter clockwise.
Thin material and/or change to larger
fluid nozzle size.
Tighten to 18–20 Nm (13–15 ft-lbs).
Push in or replace.
Clean.
Replace cup and lid.
Back fluid adjusting knob out or change
to larger fluid nozzle size.
Increase air pressure and
rebalance gun.
Reduce pressure.
Adjust to proper distance.
Move at moderate pace, parallel to
work surface.
Remix properly.
Reduce pressure.
Reduce air pressure.
Adjust to proper distance.
Slow down.
Adjust.
Tighten.
Replace.
TB-1026-D
13