Q: I have a question about the influence of acrylic polyurethane wet paint on powder coating applications (polyester, epoxy-polyester, and epoxy). Since acrylic powders are a known contaminant that can form craters, would we have a problem if we painted parts with acrylic polyurethane wet paint near (approximately 30 meters) our powder paint installation?
A: The answer is maybe. I have encountered contamination from liquid paint sprayed about 30 meters from a powder booth that caused crater defects in the finished coating. In this case, it was silicone paint that was sprayed into the environment near a powder spray operation. The paint mist would drift toward the air intake of the powder coating system and contaminate the spray booth air. This only happened when the liquid paint was sprayed on parts in a common area of the facility.
Whether a liquid acrylic urethane would do the same is unknown. I recommend that you obtain a sample of the liquid acrylic paint and conduct a test. Spray a fine mist of the paint onto a scrap part or test panel then apply a powder coating to it. Just use a light mist to simulate what could happen in the nearby environment. Cure the powder and observe the results. If the acrylic polyurethane paint contaminates the powder coating, then isolate your liquid spray area and filter the incoming air for the powder coating system.