Typically most air spray guns will have two primary controls or adjustments which allow the spray gun to be adjusted for optimal paint atomisation and spray fan pattern adjustment to suit the object being spray painted.
These two main spray gun adjustments are firstly the fluid control adjuster and secondly fan pattern width control adjuster.
The fluid adjustment control changes the distance that the fluid needle in the spray gun is able to travel out of and away from the fluid nozzle opening. As the fluid needle is able to move further out and away from the fluid nozzle the flow of paint will increase. Turning a fluid adjustment control clockwise to restrict paint flow in an air paint spray gun limits the distance the fluid nozzle is able to travel out of the fluid nozzle which in turn restricts the flow of paint. It is usually recommended to begin spray painting with this adjustment turned clockwise to the limit wear no paint will flow when the trigger is pulled and then begin to adjust the control counterclockwise until an adequate amount of paint is being sprayed.
The fan control on a spray gun can usually close off the flow of air completely to the air horns on a spray gun air cap which will result in a round or conical spray pattern. As with the fluid adjustment control it is usually recommended to begin spray painting with the fan control turned counterclockwise to shut off the flow of air to the air cap air horns completely.
As the fluid adjustment control is opened, as described previously above, and paint begins to spray from the spray gun slowly begin to increase the fan control by turning in a counterclockwise direction as well. Alternate between increasing the fluid adjustment control and the fan adjustment control until an adequate flow of correctly atomised paint, at the required fan pattern width, is achieved.