Common Paint and Stain Finish Quality Issues and Their Solutions
Fish eye
Fish eye is much like the appearance that a soap bubble creates on a surface; it creates a distorted oily appearance. Fish eye typically occurs due to oil contaminating your finish. This can be due to maintenance using silicone lubes for your spray equipment, oil in your air line, or oil drifting from nearby work areas. To eliminate fish eye eliminate oil from your air supply, your spray area, and your spray equipment by using the correct lube.
Dry spray
Dry spray is paint that appears like sandpaper after being applied. This is almost always due to having to high of air pressure or not enough fluid pressure. To fix this issue you should reduce your air pressure to your gun or increase your fluid pressure. You would increase fluid pressure if you wish to have a high level of production or if you want to remain at the same speed of coverage reduce your air pressure.
Uneven coating
This can occur when the air cap becomes defective or clogged. To determine if the air cap is the source of your troubles spray continuously for a moment and then flip the air cap 180 degrees. You then spray again and observe the pattern, if the uneven pattern changed sides then your air cap needs cleaned or replaced
Paint runs
Paint runs occur when there is not enough atomization air applied or an operator is not moving fast enough to keep up with the guns fluid output. To resolve this issue the painter needs to check his spray atomization, if it is to much fluid then increase atomization air. However, if the atomization looks fine then the painter should consider reducing fluid and air to the gun or moving faster.
By understanding why finishes end looking wrong we can correct the underlying issue resulting in better finish quality and more efficient painting.