TM 5-4940-228-14
NOTE
Air nozzle was removed to prevent
paint build up inside while spraying
without air.
f. Open air motor needle valve slowly while
watching motor shaft, keep opening air motor nee-
dle valve until a slow motor shaft rotation is ob-
served (Fig. 2-3), This will keep your paint stirred
continuously while you are spraying.
g. Adjust spraying pressure air regulator to 20
psi as indicated on spraying pressure air gage (Fig.
2-3).
h. Pull trigger on spray gun while alternately
adjusting spraying pressure air regulator and fluid
pressure air regulator until satisfactory spray is ob-
tained.
i. Adjust fan control to obtain desired width of
spray pattern (Fig. 2-4).
NOTE
For proper operation, keep atomizing
air pressure as low as possible. Proper
fluid pressure depends on type of
paint, viscosity, length of hose, height
of spray gun above tank, and desired
speed of application. Experimentation
on the part of the operator will be nec-
essary to obtain the best combination
of pressures and adjustment settings
when becoming familiar with equip-
ment and when spraying different ma-
terials. Paint should atomize into fine
particles which do not splatter
against painted surfaces, but flow to-
gether to produce an even coat.
j. Hold spray gun six to twelve inches (15 to 30
cm) from work and at right angles to surface to be
painted. Point spray gun directly at work, pull trig-
ger and move spray gun at a steady speed. The
stroke should be started before trigger is pulled and
the trigger released before the end of each stroke
(Fig. 2-7). Overlap each stroke by approximately
one third the width of the fan.
NOTE
Slight pull on trigger emits air only
which can be used for dusting. Pull
trigger all the way back when paint-
ing.
k. If an area is inconvenient to reach with the
spray gun, it will be necessary to attach the nozzle
extension as follows (Fig. 2-4):
(1) Turn handle on fluid pressure air regu-
lator and spraying pressure air regulator counter-
clockwise (Fig. 2-3).
(2) Open slide valve to relieve pressure on the
pressure (paint) tank. Wait for pressure to exhaust
from tank and observe pressure gages for “0” read-
ing before proceeding (Fig. 2-3).
(3) Remove air nozzle by hand and fluid noz-
zle with an 11/16 inch (17.46 cm) open end wrench
(Fig. 2-3).
(4) Inspect fluid nozzle gasket for tears,
cracks or damage. Replace, if necessary.
(5) Attach fluid extension to spray gun head;
next, slide air extension over fluid extension and
lock in place with lock ring.
(6) Adjustments and operation are the same
as spraying with the spray gun alone.
l. To spray small quantities of paint, connect
pressure cup to spray gun as follows (Fig. 2-4):
(1) Remove black fluid hose from spray gun
head.
(2) Remove 1/8 inch (3.18 cm) pipe plug next
to air connection at spray gun handle.
(3) Remove pressure tube from pressure cup
and install 1/8 inch (3.18 cm) pipe fitting end into
spray gun handle.
(4) Attach pressure tube to pressure cup.
(5) Attach pressure cup assembly to fluid con-
nection on spray gun.
(6) Mix and strain paint thoroughly, so that it
is free from lumps, skins, and foreign matter before
pouring it into cup. Paint should be at hand-brush-
ing consistency. Screw cup into cover assembly.
(7) Adjust spraying pressure air regulator on
pressure (paint) tank to 20 psi. Pull trigger and ad-
just fluid control for satisfactory spray; adjust fan
control for desired spray width. Higher pressure
may be required.
WARNING
Do not exceed 45 psi in the pressure
cup. Cup could burst and cause injury
to operator.
NOTE
Spray with same techniques as used
with spray gun alone.
2-9
