TB-1016-A
13
Troubleshooting Possible Problems
in Operation
CONDITION
CAUSE
CORRECTION
Heavy top or
bottom pattern
Horn holes plugged.
Clean. Ream with non-metallic point.
Obstruction on top or bottom
of fluid nozzle.
Clean.
Cap and/or nozzle seat dirty.
Clean
Heavy right
or left side
pattern
Left or right side horn holes plugged.
Clean. Ream with non-metallic point.
Dirt on left or right side of
fluid nozzle.
Clean.
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
pattern
Spreader adjustment valve set
too low.
Turn out counter clockwise to achieve
proper pattern.
Atomising pressure too low.
Increase pressure.
Material too thick.
Thin to proper consistency.
Split spray pattern
Atomisation air pressure too high.
Reduce at regulator or gun handle.
Fluid adjusting knob turned in
too far.
Turn out counter clockwise to achieve
proper pattern.
Spreader adjusting valve set too high.
Turn in clockwise to achieve proper
pattern.
Jerky or fluttering spray
*Loose or damaged fluid nozzle/seat.
Tighten or replace.
Loose or broken cup fluid nipple.
Tighten or replace cup.
Material level too low.
Refill.
Container tipped too far.
Hold more upright.
Obstruction in fluid passage.
Back flush with solvent.
Loose fluid needle packing nut.
Tighten.
Damaged fluid needle packing.
Replace.
Unable to get round spray
Spreader valve 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, blow out
gun air passages.
Fluid adjusting knob not
open enough.
Turn out counter clockwise.
Fluid too heavy for gravity feed.
Thin material and/or change to larger
fluid nozzle size.
Paint bubbles in cup
Fluid nozzle not tight.
Tighten to 18–20 nm (13-15 ft-lbs).
Fluid leaking or dripping
from cup lid
Cup lid loose.
Push in or replace.
Dirty cup or lid.
Clean.
Cracked cup or lid.
Replace cup and lid.
Starved spray pattern
Inadequate material flow.
Back fluid adjusting knob out or change
to larger fluid nozzle size.
Low atomisation air pressure.
Increase air pressure and
rebalance gun.
Excessive overspray
Too much atomisation air pressure.
Reduce pressure.
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 atomisation air pressure.
Reduce pressure.
Dry spray
Air pressure too high.
Reduce air pressure.
Gun 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.
Packing worn.
Replace.
*Most common problem.