Troubleshooting Possible Problems In Operation - DeVilbiss JGA PRO Series Technical Bulletin

Troubleshooting Possible Problems in Operation

CONDITION
Heavy top or
bottom
pattern
Heavy right or
left side
pattern
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. If problem persists, renew nozzle.
Heavy
centre
pattern
Split spray
pattern
Jerky or fluttering spray
Paint bubbles in cup
Fluid leaking or dripping from cup
lid
© 2013 Finishing Brands UK Ltd.
CAUSE
Horn holes plugged.
Obstruction on top or bottom of fluid
nozzle.
Cap and/or nozzle seat dirty.
Left or right side horn holes plugged.
Dirt on left or right side of fluid
nozzle.
Spreader adjustment valve set too
low.
Atomising pressure too low.
Material too thick.
Air pressure too high.
Fluid adjusting knob turned in too
far.
Spreader adjusting valve set too
high.
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
Fluid nozzle not tight.
Cup lid loose.
Damaged Cup Lid Gasket
Fluid leaking from vent hole
15
CORRECTION
Clean. Ream with non-metallic
point.
Clean.
Clean.
Clean. Ream with non-metallic
point.
Clean.
Turn out counter clockwise to
achieve correct pattern.
Increase pressure.
Thin to correct consistency.
Reduce at regulator or gun handle.
Turn out counter clockwise to
achieve correct pattern.
Turn in clockwise to achieve
correct
pattern.
Tighten or replace
Tighten or replace cup
Refill
Hold more upright
Back flush with solvent
Tighten
Replace
Tighten to 18–20 nm (13-15 ft-lbs).
Tighten Cup Lid.
Replace Cup lid Gasket
Clean drip free diaphragm