DeVilbiss CVi Guide D'utilisation page 8

Page 8 SB-2-662-C
TROUBLESHOOTING
CONDITION
Heavy top or
bottom pattern
Heavy right or left side pattern
Heavy center pattern
Split spray pattern
Jerky or fluttering spray
Unable to get round spray
Will not spray
Excessive overspray
Excessive fog
Dry Spray
Fluid leaking from packing nut
Fluid leaking or dripping from
front of pressure feed gun
Runs and sags
Thin, sandy coarse finish
drying before it flows out
*Most common problem.
C USE
Horn holes plugged.
Obstruction on top or bottom of fluid tip.
Cap and/or tip seat dirty.
Left or right side horn holes plugged.
Dirt on left or right side of fluid tip.
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 tip. 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.
2) If the defect is not inverted, it is on the fluid tip. Check for a fine burr on the edge of the fluid tip.
Remove with #600 wet or dry sand paper.
3) Check for dried paint just inside the opening. Remove paint by washing with solvent.
Fluid pressure too high for atomization
air (pressure feed).
Material flow exceeds air cap's capacity.
Spreader adjustment valve set too low.
tomizing pressure too low.
Material too thick.
tomization air pressure too high.
Fluid pressure too low (pressure feed only).
Spreader adjusting valve set too high.
*Loose or damaged fluid tip/seat.
Material level too low.
Container tipped too far.
Obstruction in fluid passage.
Loose or broken fluid tube or fluid inlet nipple.
Dry or loose fluid needle packing nut.
Spreader adjustment screw not seating properly.
ir cap retaining ring loose.
No air pressure at gun.
Fluid pressure too low
Fluid needle adjusting screw not open enough.
Fluid too heavy for suction feed.
Too much atomization air pressure
Gun too far from work surface.
Improper stroking (arcing, gun motion too fast).
Too much, or too fast-drying thinner.
Too much atomization air pressure.
ir pressure too high.
Gun tip too far from work surface.
Gun motion too fast.
Gun out of adjustment
Packing nut loose.
Packing worn or dry
Packing nut too tight.
Dry packing.
Fluid tip or needle worn or damaged.
Foreign matter in tip.
Fluid needle spring broken.
Wrong size needle or tip.
Too much material flow.
Material too thin.
Gun tilted on an angle, or gun motion too slow.
Gun too far from surface.
Too much air pressure.
Improper thinner being used.
CORRECTION
Clean. Ream with non-metallic point.
Clean.
Clean.
Clean. Ream with non-metallic point.
Clean.
Balance air and fluid pressure.
Increase spray pattern width with
spreader adjustment valve.
Thin or lower fluid flow.
djust.
Increase pressure.
Thin to proper consistency.
Reduce at transformer or gun.
Increase fluid pressure (increases gun
handling speed).
djust.
Tighten or replace.
Refill.
Hold more upright.
Backflush with solvent.
Tighten or replace.
Lubricate or tighten.
Clean or replace.
Tighten.
Check air supply and air lines.
Increase fluid pressure at tank.
Open fluid needle adjusting screw.
Thin material or change to pressure feed.
Reduce pressure.
djust to proper distance.
Move at moderate pace, parallel towork surface.
Remix properly.
Reduce pressure.
Reduce air pressure.
djust to proper distance.
Slow down.
djust.
Tighten, do not bind needle.
Replace or lubricate.
djust.
Lubricate.
Replace tip & needle with lapped sets.
Clean.
Replace.
Replace.
djust gun or reduce fluid pressure.
Mix properly or apply light coats.
Hold gun at right angle to work and adapt to
proper gun technique
Check distance. Normally approx. 8".
Reduce air pressure and check spray pattern.
Follow paint manufacturer's mixing instructions.