What is commonly a cause of an unbalanced spray?

The most common cause of an unbalanced spray is dry material in or on the nozzle. When there is dried paint or debris obstructing the nozzle, it can restrict the flow of the paint and lead to an uneven distribution. This blockage can disrupt the intended spray pattern, causing some areas to receive too much paint while others may receive insufficient amounts, leading to an unbalanced finish.

In contrast, factors like excessive distance from the surface, too much paint being applied, or too low air pressure can also affect the spray pattern, but they typically do not cause as immediate and significant an issue as a clogged nozzle. For instance, spraying from too far away might result in a misty application or a dry spray, which can be adjusted by simply moving closer. Similarly, applying too much paint at once can cause runs or sags, but does not usually lead to a completely unbalanced spray. Low air pressure can affect atomization but usually presents different issues rather than a directly unbalanced output. Therefore, the presence of dry material in or on the nozzle directly leads to the most pronounced unbalanced spray effect.