How Do I Control my Spray Pattern?

Every part is different. Different sizes, different geometries, different intricacies, etc. In addition to that, may coatings have different properties (and costs) as well. That’s why it is important to dial in your spray gun pattern so that you are optimally coating your part and not wasting material in the process. No two jobs are completely alike; therefore there is not a “one size fits all” setting from job to job and material to material.

Most spray guns have different knobs and dials on them that each control a different aspect in regards to the pattern and amount of the material you are spraying. It can be confusing looking at them all at first but with a little bit of practice you will be able to successfully augment your spray pattern for your particular job at hand. Here are the basic controls that come on mostly every spray gun:

Round/Wide Jet Regulation Control: This setting is usually presented as a knob on the body of the spray gun and is available if your spray gun is equipped with a wide jet air cap (an air cap with “horns” on it). This knob simply controls the amount of air that flows through those horns in the air cap. The more air that flows through, the wider the spray pattern. The less air that flows through, the rounder the spray pattern.

Atomizing Air Control: This setting is also usually presented as a knob on the body of the spray gun (refer to your spray gun manual to determine which knobs do what). This knob controls the atomizing air that flows into the spray gun, or the “master air”. If you turn this setting all the way off there will be no air flowing through the spray gun and you will just get a solid stream of paint coming out of the nozzle. Use this setting to balance the amount of atomization you need with the amount of overspray that is produced. More atomization typically means more overspray.

Material Flow Regulation: This setting is usually presented as a knob near the back of the spray gun body and behind the needle. It controls how far the needle retracts from the nozzle when the spray gun is triggered. This controls how much material is allowed to flow out of the nozzle. This is a fine tune setting however as the main control for material flow is determined by the needle/nozzle size on the spray gun itself. Typically, this is set to wide open but is available to be closed down if the need arises.

Jorge Flores, Marketing Coordinator
Coating Equipment Technology, Inc