The equipment and techniques used to paint aircraft are covered in this section. You will frequently use and maintain spray guns, air compressors, and regulators. Therefore, the material in this section should be important to you.

The spray gun atomizes the material to be sprayed. You direct and control the spray pattern by manipulating and adjusting the spray gun. Spray guns are usually classed as either suction feed or pressure feed. The types are divided by two methods-the type of container used to hold the paint material and the method in which the paint is drawn through the air cap assembly.

Figure 14-32.-National star insignia. 

Figure 14-33.-Suction-feed spray gun.

SUCTION FEED. -The suction-feed spray gun is designed for small jobs. The container for the paint is connected to the spray gun by a quick-disconnect fitting, as shown in figure 14-33. The capacity of this container is approximately 1 quart. The fluid tip of this type of spray gun protrudes through the air cap, as shown in figure 14-34. The air pressure rushing past the fluid tip causes a low-pressure area in front of the tip. This causes paint to be drawn up through the fluid tip, where it is atomized outside the cap by the air pressure. 

PRESSURE FEED. -The pressure-feed spray gun is designed for use on large jobs where a large amount of spray material is to be used. The spray material is supplied to the gun through a hose from a pressurized tank. This spray gun is designed to operate on high-volume, low-pressure air. This type of equipment eliminates the evaporation of the volatile substances of the mixture before striking the surface because the paint and air are mixed in the tanks. In other words, a wetter coating is applied.