When choosing a Spray Gun, an important choice (depending on the type of Spray Gun itself) is nozzle size. The nozzle is important to determine the efficiency with which the material is atomized. In turn, this determines the quality of the coating you get from your spraying process. A general rule of thumb is that the higher the viscosity of the material, the larger the nozzle size required. If the size is too small, the material supply is blocked and adequate coverage cannot be achieved. Conversely, if it is too large, material is wasted because there is not enough air to atomize the amount of material coming out of the nozzle.
When dealing with paints, stains, and clearcoats, there is usually experience in determining nozzle size. However, when working with other materials such as mold release agents, different types of adhesives, abrasive media, marking inks, etc., the lines start to blur a bit. This is especially true when working with these types of materials because you're also looking at different needle and nozzle types and sizes.
In these cases, it is important to have a testing facility with access to equipment and materials in order to determine the correct nozzle size for your specific coating application.
