The first step of Spray Gun operation is the adjustment of the Spray for uniformity over the desired width, too
much Air Pressure, i.e., too much atomizing Air Pressure at the Nozzle for the particular material being used will
thin out the center of the spray pattern. It will cause excessive atomization or vapor about the main body of the
spray. This condition can be controlled by lowering either Air Pressure at the Air Separator or adjusting the Reg-
ulator on top of the Pressure Tank or by properly setting the Air Adjustment Valve. An insufficient Air Pressure,
i.e., too little air pressure at the Spray Gun Nozzle for the particular material to be used causes a spatter effect,
the material covering the surfaces in small beads, drops or dots. This condition is controlled by increasing the
Air Pressure at the Air Separator or at the Pressure Tank.
The width of the Spray is controlled by the Air Adjustment valve (Fig. 1). Turn the Air Adjustment Valve
clockwise to decrease the spray, counter clockwise to increase the spray. To produce a round spray pattern or
spot, close the Air Adjustment Valve.
The amount of material flow is controlled by the fluid Adjustment Screw (Fig. 1). Turn Adjusting Screw to
the right to decrease the amount of Fluid flow and to the left to increase it.
With certain materials, too wide a spray adjustment will cause the spray pattern to split, i.e., the pattern be-
comes thin in the center and heavy at the ends, when this occurs, reduce the width of the spray.
Excessive material flow for the speed of stroke will cause runs or sags on the surface. Regulate the fluid
flow to your speed of stroke.
The atomizing air pressure passing into the Spray Gun Nozzle is regulated to meet varying conditions of size
of Gun Nozzle, weight or viscosity of paint, the material of the surfaces to be sprayed and the desired speed of
gun operation. The atomization pressure will range from 20 to 80 pounds. Although for average materials and
conditions, pressure from 40 to 60 pounds will be most satisfactory. Always use the lowest pressure that will give
the desired results. A little experience will teach the Operator the most satisfactory pressures for the materials
Materials should be stirred thoroughly and reduced according to manufacturer's instructions; then strained
into material container through cheese cloth or wire screen of such mesh or gauge as to remove all lumps, skins,
etc. The straining of all material before introduction into the material container is of utmost importance, as it
will prevent the consequent obstruction of spray gun passages.
A short practice period, using a cardboard, wood or metal surface is recommended so as to become familiar
with the adjustments and operation of the spray g u n . Do not attempt to operate the spray gun too rapidly at first.
Learn to adjust and handle it and s p e e d w i l l f o l l o w .
The stroke is made with a free arm motion, keeping the gun body perpendicular to, and from arr equal distance
from the surface at all points of the stroke. Keep the gun 6 to 8 inches from the surface to be sprayed and move it
across the surface with steady, even strokes.