What is the primary role of the air cap in a gravity feed spray gun?

The primary role of the air cap in a gravity feed spray gun is to atomize the paint. This component plays a crucial part in the spray gun's operation by mixing air with the liquid paint as it exits the tip. When air is introduced through the air cap, it helps break down the paint into a fine mist, allowing for an even and controlled application.

This atomization process is essential for achieving a smooth finish, as it determines how well the paint adheres and covers the surface. By creating a fine spray, the air cap ensures that the paint particles are small enough to provide an even coat, reducing the risk of runs or heavy spots on the surface.

While there are elements of the spray gun that can influence the fluid needle and adjust the spray pattern, these functions are secondary to the primary role of the air cap in facilitating the atomization process. The air cap does not solely regulate air pressure; that function is typically managed by a regulator separate from the air cap. Therefore, the correct understanding of the air cap's role is fundamental for effective use of gravity feed spray guns in painting and refinishing applications.