This general guide to using an air paint spray gun can apply to conventional air paint spray guns, HVLP air paint spray guns and LVLP air paint spray guns in gravity feed, suction or pressure feed variants.
The first thing to check is the paint manufacturers technical data sheet which will recommend a fluid nozzle size and often an air paint spray gun type for use with their coating.
The technical data sheet should also specify maximum thinning that is allowed for air paint spray applications.
Check the paint spray gun manufacturers recommendation for air compressor size to ensure your air compressor is adequate, and also check if the spray gun manufacturer recommends an air pressure operating range.
Start by mixing the paint thoroughly using stirring, agitation or shaking.
If the paint manufacturer suggests a minimum thinning amount for air paint spraying, thin a small amount of the paint to their recommended amount of thinning and again mix thoroughly, otherwise start your test with no thinners added to the paint at this stage.
Place a small amount of your paint, 100 ml is usually about right, and start with the air pressure to the spray gun regulated to the manufacturers minimum recommendation, close the fan control setting on the spray gun by winding it fully clockwise, and also turn the fluid control knob at the back of the spray gun fully clockwise. If there is an air regulating valve on the gun handle it is usually best to open this valve fully counterclockwise at this stage.
Connect the air to the spray gun and squeeze the trigger. At this stage you will hear air begin to flow from the spray gun and while this is occurring begin to turn the fluid control knob at the back of the spray gun until paint begins to flow.
Begin spraying paint on a test area and continue opening the fluid control until an adequate amount of paint is being sprayed.
Carefully watch the centre of the paint spray pattern and if it appears heavy more air pressure may be required. Begin opening the fan control to increase the fan width to achieve a desired pattern.
If air pressure needs to be increased dramatically to achieve atomisation additional thinning may be required. Also if there is too much orange peel effect additional thinning may assist with levelling and reduction of peel effect.
The bottom line is every time you start a new spray painting job it pays to set up the air paint spray gun with the fluid control at minimum setting, the paint spray fan control at minimum setting, and the air pressure regulated to minimum, and with the paint minimally thinned.
From this starting point incrementally increase the fluid flow, spray fan width, air pressure and paint thinning until the desired finish can be achieved.
This will ensure your air spray gun is set to achieve the maximum transfer efficiency, and least amount of paint over spray that it is capable of delivering.