SB-2-243-F Page 5
TROUBLESHOOTING
CONDITION
CAUSE
CORRECTION
Heavy top or bottom
Horn holes plugged.
Clean. Ream with nonmetallic point.
pattern
Obstruction on top or bottom of fluid tip.
Clean.
Cap and/or tip seat dirty.
Clean.
Heavy right or left side pattern
Left or right side horn holes plugged.
Clean. Ream with nonmetallic point.
Dirt on left or right side of fluid tip.
Clean.
Remedies for top-heavy, bottom-heavy, right-heavy and left-heavy patterns:
1) Determine if obstruction is on cap or fluid tip. Do this by making a test pattern. Then, rotate cap one-half
turn and spray another pattern. If defect is inverted, obstruction is on air cap. Clean air cap as previously
instructed.
2) If defect is not inverted, it is on fluid tip. Check for a fine burr on edge of fluid tip. Remove with #600 wet
or dry sand paper.
3) Check for dried material just inside opening. Remove by cleaning.
Heavy center pattern
Material flow exceeds air cap’s capacity.
Thin or lower fluid flow.
Atomizing pressure too low.
Increase pressure.
Material too thick.
Thin to proper consistency.
Split spray pattern
Fluid adjusting knob turned in too far.
Back out counterclockwise to achieve proper flow.
Atomization air pressure too high.
Reduce air pressure.
Jerky or fluttering spray
*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.
Clean according to material supplier’s recommendations.
Loose or broken fluid tube or fluid inlet nipple.
Tighten or replace.
Dry or loose fluid needle packing nut.
Lubricate or tighten.
Will not spray
No air pressure at gun.
Check air supply and air lines.
Fluid needle adj. screw not open enough.
Open fluid needle adjusting screw.
Fluid pressure too low with internal
Increase fluid pressure at tank.
mix cap and pressure tank.
Excessive overspray
Too much atomization air pressure.
Reduce pressure.
Gun too far from work surface.
Adjust to proper distance.
Improper stroking (arching, gun motion
Too fast. Move at moderate pace, parallel to work surface.
Dry spray
Air pressure too high.
Decrease 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 loose.
Tighten, do not bind needle.
packing nut
Packing worn or dry.
Replace or lubricate.
Fluid leaking or dripping from
*Foreign matter in tip.
Clean.
front of gun
Packing nut too tight.
Adjust.
Dry packing.
Lubricate.
Fluid tip or needle worn or damaged.
Replace tip & needle with lapped sets.
Fluid needle spring deformed or broken.
Replace.
Runs and sags
Too much material flow.
Adjust gun or reduce fluid pressure.
Material to thin.
Mix properly or apply light coats.
Gun tilted on an angle.
Hold gun at right angle to work and adapt to proper
gun technique.
Thin, sandy coarse finish
Gun too far from surface.
Check distance. Normally 6-8".
Drying before it flows out
Too much air pressure.
Reduce air pressure and check spray pattern.
Improper thinner being used.
Follow paint manufacturer’s mixing instructions.
* Most common problem.
SPRAY GUN LUBRICATION
Daily, apply a drop of
•SSL-10
at trigger
bearing stud (19) and the stem of the air
valve (14) where it enters the air valve as-
sembly (17). The shank of the fluid needle
(30) where it enters the packing nut (23)
should also be oiled. The fluid needle pack-
ing (22) should be lubricated also.
Make
sure baffle (6) and retaining ring (1) threads
are clean and free of foreign matter. Before
assembling air cap to baffle, clean the re-
taining ring and baffle threads thoroughly,
then add two drops of •SSL-10 spray gun
lube to threads.
A. Trigger points
B. Packing
C. Adjusting valves
D. Baffle & retaining ring
threads
E. Air valve cartridge
• Material safety data sheet available from
DeVilbiss upon request.
The fluid needle spring (32) and air valve
spring (15) should be coated on the ends
with a light grease, ensuring that any excess
grease will not clog the air passages. For
best results, lubricate the points indicated
daily using •SSL-10 spray gun lube.
A
C
D
B
E
