31
30
Adjustment of the Atomizing Air Pressure
The atomizing air pressure is adjusted at the air pressure reducing valve of the com-
pressor system. Please comply with the operating instructions and safety warnings
issued by the manufacturer.
If you wish to change the spraying pattern beyond the adjustments outlined so far,
you must retool the spray gun (See
5.5 Retooling of Spray Gun
).
WALTHER offers a great variety of air cap/-material nozzle/needle combinations for
this purpose.
Correcting of Spray Pattern Imperfections
The following table shows what to do to correct a spray pattern.
Spray pattern
test
Fault
Necessary adjustment
Swollen centre
• Spray jet should be flatter
Swollen ends
• Spray jet should be rounder
Coarse pearl effect
• Increase atomising air pressu-
re
Unduly thin paint layer
in centre
• Decrease atomising air pres-
sure
Split centre
• Increase nozzle diameter
• Reduce atomising air pressure
• Increase material pressure
Split centre
• Decrease material pressure
• Increase atomising air pressure
5.5
Retooling of Spray Gun
Combinations of air cap, material nozzle and needle, designed to match specific
spraying media tpyes and grades, form a unit - namely the nozzle insert assembly.
In order maintain the desired spray-finish quality standard always replace the
complete nozzle insert assembly.
Warning
Prior to retooling: Make sure that the spray gun is in unpressurized condition, i.e. all
air and material inputs must be shut off - if not, imminent risk of injury.
Note
In order to perform the following procedures please use the drawing at the beginning
of these operating instructions.
Replacement of Air Cap
1. Unscrew the serrated air head nut (item 1) from the gun body (item 5) on the
front part of the gun.
2. Pull the air head (Item 2) of the gun body.
3. Position the required air cap on the gun body.
4. Screw the air head nut in (Item 1) onto the gun body.
Replacement of Material Control Nozzle and Needle
1. Remove the air control head (Item 2) (see
5.5 Replacement of Air Control Head
).
2. Unscrew the material nozzle in (Item 4) from the gun body (item 5) (width over
flats of hex. nut 13).
3. Unscrew the spring bushing (item 12) from the cap (item 9)
4. Remove the needle springs (item 11).
5. Unscrew the air head nut (item 1) from the rear part of the gun.
6. Extract the cap (item 9) from the gun body.
7. Pull out the material needle (item 10).
Installation of the new nozzle insert assembly and the remaining parts is performed
in the reverse order.
Note
The needle setting (x) is 112 mm from the needle tip to the counter-screw.
6 Cleaning
6.1
Safety Warnings
•
Prior to any servicing and repair work: Make sure that the spray gun is in unpres-
surized condition, i.e. all air and material inputs must be shut off - if not, immi-
nent risk of injury.
•
No open fires, naked light and smoking allowed in the work area. When spraying
readily flammable media such as cleaning solutions, there is an increased risk
of fire and explosion.
•
Observe the safety warnings issued by the manufacturer. Aggressive and corro-
sive media represents risks and hazards to personal health.
6.2
Cleaning - Complete
Regular cleaning and lubrication of the spray gun has to be performed, in order to
increase the service life and the function of the spray gun.
Clean the gun only with cleaning solutions recommended by the manufacturer of the
spraying material used at the time. It is important to make sure that cleaning
solutions do not contain any of the following constituents:
x
desired spray result
