Maintenance - DeVilbiss SB-2-001-J Troubleshooting Manual

Overlap each stroke 50%. Less than 50% will result
in streaks on the finished surface. Move the gun at
a constant speed while triggering since the material
flows at a constant rate.
Another technique of triggering is referred to as
"feathering". Feathering allows the operator to limit
fluid flow by applying only partial trigger travel.
Spray edges and corners first. This is called band-
ing. Banding reduces overspray yet provides good
coverage on corners.
Incorrect
Correct
Figure 12 Spray Techniques
REPLACEMENT OF PARTS
Follow specific gun Service Bulletin exploded view
for replacing parts. There are areas requiring proper
sequence.
The fan adjustment assembly should only be in-
stalled after turning the knob out. If left in, the stem
or needle could jam against the seat.
Pull trigger or remove fluid adjusting screw prior
to tip tightening. Tip and needle damage can occur.
Spray guns have some combination of plastic,
copper, leather and soft packings and gaskets. It
is recommended that these be replaced if the as-
sembly is removed or when doing an overall repair.
The fluid needle packing must be replaced when
the packing nut bottoms out.
It is recommended to oil a new packing or needle
before assembly. Packing nuts should be tightened
just enough to seal (fluid leakage on pressure feed,
suction of air on suction feed). Too tight will bind
the needle as well as shorten life of packing. When
replacing the fluid tip or fluid needle, it is recom-
mended to replace both at the same time. Matched
sets are available for most guns on pressure feed
combinations.

MAINTENANCE

AIR CAP - Remove the air cap from the gun and
immerse it in clean solvent. Blow it dry with com-
pressed air.
If the small holes become clogged, soak the cap
in clean solvent. If reaming the holes is necessary,
use a toothpick, a broomstraw or some other soft
implement.
Do not clean holes with a wire, a nail or a similar
hard object. Doing so could permanently damage
the cap by enlarging the jets, resulting in a defec-
tive spray pattern.
Figure 13 Cleaning Air Cap
Suction or Pressure Feed Cleaning - A suction or
pressure feed gun with attached cup should be
cleaned as follows:
Turn off the air to the gun, loosen the cup cover
and remove the fluid tube from the paint. Holding
the tube over the cup, pull the trigger to allow the
paint to drain back into the cup.
Don't tilt the gun in any direction. This will result in
uneven paint build causing runs and sags.
Empty the cup and wash it with clean solvent and
a clean cloth. Clean off the outside of the tube. Fill
halfway with clean solvent and spray it through
the gun to flush out the fluid passages. Be sure to
comply with local codes regarding solvent disposal.
Then remove the air cap, clean it as previously
explained and replace it on the gun.
Wipe off the gun with a solvent soaked cloth, or if
necessary, brush the air cap and gun with a fiber
brush using clean-up liquid or thinner.
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