Spray Pattern Troubleshooting Chart - Graco A Series Instructions-Parts List Manual

SPRAY PATTERN TROUBLESHOOTING CHART

Installing and servicing this equipment requires access to parts which may cause electric shock or other serious
bodily injury if the work is not performed properly. Do not install or service this equipment unless you are trained and
qualified.
To reduce the risk of serious bodily injury, including splashing fluid or solvent in the eyes or on the skin, always
follow the Pressure Relief Procedure on page 9 before checking, adjusting, cleaning or repairing the gun or any
part of the system. Disconnect the fluid hose from the gun.
NOTE: Check all possible remedies in the Troubleshooting Charts before disassembling the gun.
PROBLEM:
IMPROPER SPRAY
PATTERN
Fluttering or spitting
spray
Streaks
NOTE: Some improper patterns are caused by the improper balance between air and fluid.
WARNING
CAUSE
Insufficient fluid supply.
Dry or worn fluid needle packing
or loose packing nut permits air
to get into fluid passage.
Loose fluid nozzle or damaged
fluid nozzle taper seat.
Dirt between fluid nozzle, taper
seat and body.
Loose or cracked coupler at
fluid inlet.
Loose fluid tube in cup or tank.
Fluid build–up on air cap; partially
clogged horn holes. Full air pres–
sure from clean horn hole forces
fan pattern toward clogged end.
Damaged fluid nozzle or air
cap holes.
Fluid build–up on the perimeter
of fluid nozzle orifice, or partially
clogged fluid nozzle orifice
Too high atomization air pressure.
Fluid too thin.
Not enough fluid pressure
Low atomization air pressure
Fluid too thick
Too much fluid.
Last coat of fluid applied too wet.
Too much air pressure.
Insufficient air pressure.
Non–uniform spray pattern.
SOLUTION
Adjust fluid regulator or fill fluid tank.
Lubricate or replace packing,
tighten packing nut.
Tighten or replace fluid nozzle.
Clean.
Tighten or repair.
Tighten.
Clean with soft implement or
submerge in suitable solvent and
wipe clean.
Replace damaged part.
Remove obstruction. Never use
wire or hard instruments.
Reduce air pressure or adjust air
adjusting valve.
Regulate fluid viscosity.
Increase fluid pressure.
Raise air pressure.
Regulate fluid viscosity.
Reduce fluid flow. Reduce fluid
pressure on pressure feed guns
and/or adjust fluid adjusting screw
until proper pattern is obtained.
Apply drier finish with multiple strokes.
Use least air pressure necessary.
Increase air pressure.
Clean or replace air cap.