Spray Pattern Width and Adjustment

Even if you have no problems with your spray pattern – such as a bulging center-heavy pattern, the peanut shape of a split pattern, or the cashew-like curve of a blocked wing port – then you will need to adjust the width of the pattern to match the materials you are using and the job you are undertaking.

If your gun is flinging a lot of paint onto the car’s surface, you can probably get away with a wider (and thus faster) pattern, while if volume is fairly low for whatever reason, then a narrower pattern is indicated. Use a tape measure to gauge both the distance from the air cap to the surface, and the width of the test spray pattern once you have shot it.

The testing sheet – which can be white cardboard, ordinary paper, or masking paper, since you will have this readily to hand in any case – should be mounted on a vertical surface, usually a wall, close to your work area, directly beside the vehicle to be painted. After all, you do not want to make an ideal spray pattern, and then be forced to disassemble, move, and reassemble the spray gun and its associated hoses at the worksite. This would defeat the whole purpose of adjusting the spray pattern to begin with, as the settings would not survive the transfer of the spray gun from one place to another.

To adjust the settings properly for a good coverage and spray pattern, the pattern should be tested at the painting distance. Keep the air open as far as it will go (within the pressure limits of the gun, of course) and then adjust the spray pattern using the material control to feed different amounts of paint into the air stream until you achieve the desired width of spray pattern.

4 to 6 inches is the usual width for a spray pattern, depending on the volume of material delivery; low volume calls for a 4” spray pattern, while 6” is more appropriate for high volume.  Six inch patterns are also good for pickup trucks, larger cars, and similar vehicles, while the smaller strokes are appropriate for some very compact cars, motorcycles, ATVs, and other lighter transportation devices.