Proficient use of the air brush is gained only after you thoroughly know the major parts of the air brush and how they operate.
The Trigger Button is the square, chrome-plated button on top of the air brush. This is a single-action control in that it controls only the flow of air. Some air brushes have a double-action trigger button which controls both the flow of air and the amount of fluid being sprayed.
The small, Knurled Screw just below the trigger button limits the movement of the trigger button and the flow of air. This screw should be turned down (to the left) as far as it will go. Only when a spatter or stipple effect is desired should the trigger button screw be raised to the position just below the extended trigger button. Experimenting with the screw in different positions will provide a variety of lighter to heavier spatter patterns. The color droplets will increase in size as the screw is turned higher, cutting down the flow of air.
The Air Intake is located at the bottom of the airbrush in line with the slanted trigger button. Screw the small end of the air hose to the air intake and tighten with fingers until snug.
The Fluid Control is located under the front end of the air brush and protrudes into the nozzle. The knurled portion of the fluid control opens or closes the flow of fluid. Turning the control clockwise opens it wider, counter-clockwise closes it.
The Color Bottle Assembly has a friction connection which is inserted into the opening at the bottom of the fluid control and is fastened with a firm push-and-twist motion. Look for a small vent hole in the lid of the bottle assembly. This hole should be kept open and free of fluid because if it becomes clogged, the flow of air into the bottle is blocked, preventing the flow of color upward into the fluid control.
The air needed to operate the air brush can be obtained from portable or larger tank-mounted compressors. The air pressure should be about 38 psi when the air brush is not spraying; it should drop to
OPERATION
THINNING FLUIDS
Fluids that may be sprayed with the air brush range from light, or water-type consistency to heavy, or enamel-type consistency. It is most desirable that the fluid be of a viscosity that is sprayable, provides adequate coverage and yet will not run or sag. To achieve this, reduction, or thinning of the fluid may be necessary. When and how to correctly reduce or thin fluids is a matter of judgement and common sense.
STRAINING FLUIDS
Since the fluid orifices in the air brush are extremely small, it is essential that the fluid to be sprayed be free of foreign particles. It is recommended that fluids be strained through a piece of nylon stocking or similar mesh cloth before use.
CLEANING
Ninety-five percent of breakdowns in the operation of the Wren Air Brush are directly due to not keeping the air brush clean at all times, especially after each use. When using fast-drying fluids, such as lacquers, underglazes, etc. which will set up in five to ten minutes, it may be necessary to clean or immerse the fluid control end of the airbrush in compatible solvent during intermittent use