5
PROBLEM CAUSE ACTION
Fluttering Spray Pattern Insufficient fluid supply. Adjust fluid regulator or fill fluid supply
tanks.
Air in paint supply line. Check and tighten pump siphon hose con-
nections, bleed air from paint line.
Attempting to “feather” (Partially Cannot feather with an AA1500 gun.
trigger gun).
Striping Spray – Fingers Carbide tip partially plugged. Clean or replace carbide tip assembly.
Irregular Pattern Fluid builds up on carbide tip, or tip Clean carbide tip.
partially plugged.
On defective side of pattern, air horn Clean air horn holes with solvent and
holes are plugged. a soft brush.
Pattern pushed to one side, same On defective side of pattern, air horn Clean air horn holes with solvent and
side of air cap gets dirty holes are plugged. a soft brush or toothpick.
SPRAY PATTERN TROUBLESHOOTING
AIR-ASSISTED AIRLESS SPRAY GUN MAINTENANCE AND CLEANING
Maintenance of air-assisted airless spray guns includes
(1) fluid tip wear and replacement; (2) lubrication; and
(3) cleaning of the gun.
FLUID TIP
Operating an air-assisted airless spray gun with a worn
fluid tip will result in increased usage of spraying materi-
al and therefore, HAP emissions. For example, an
increase in the diameter of a tip from 0.015 inch to 0.021
inch due to wear can result in up to a 100 percent
increase in material consumption and cost. To prevent
waste in spraying material and non-value-adding costs, a
maintenance schedule that includes fluid tip inspection
and replacement must be established.
LUBRICATION
Proper lubrication is essential for optimum spray gun per-
formance. Lubrication allows the equipment to operate
easily and correctly. The spray gun should be lubricated
after each cleaning. The points that need lubrication dur-
ing the maintenance of air-assisted airless spray guns
include (1) the fluid needle packing; (2) trigger pivot
point. Gun lube is used to lubricate the fluid needle pack-
ing and trigger pivot point.
CLEANING
The following steps summarize the procedure for clean-
ing air-assisted airless spray guns:
1. Turn off the shaping air supply.
2. Turn off the spraying material pump.
3. Place the pick-up tube from the pump in a solvent
container and turn the pump on.
4. Secure the gun trigger safety switch, remove the fluid
tip, and place it in a closed solvent container.
5. Release the gun trigger safety switch and spray into a
closed container until the fluid runs clear.
6. Using a rag dampened with solvent, wipe the exterior
surface of the gun. Additionally, some solvents are
prohibited from being used for cleaning. The operator
must take care to use only approved cleaning solvents
for equipment cleaning. These materials are clearly
labeled as approved for cleaning and wash off opera-
tions. If the operator has any question on selecting
appropriate cleaning solvents, the operator should
consult a supervisor or plant environmental staff.
CAutIon
Never immerse the entire gun in solvent or thinners. Some
gun parts will lose their lubricative film and wear more
quickly. Additionally, solvents may carry impurities
throughout the gun body and allow them to clog small air
and fluid passages.
!
note
Only use solvent identified as approved for cleaning
and wash-off use.
note
During cleaning, the gun may only be sprayed into a closed
container. never flush the gun into the air or spray booth.
wARnInG
Failure to reduce pump air supply pressure or to use a
closed container can result in material “bounce-back”.
Material “bounce back” can cause injury and damage.
!
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