Sometimes called "KV burn" or "fry marks", “starring” most often occurs when applying a second or top coat when KV levels are too high, or there is insufficient distance from the spray gun to the part. Powder may begin to build as normal, but then circular shaped marks begin to appear. These marks can have a jagged edge that gives them their "star" name (see Fig. 1).
How do I fix it?
- Remove all the powder from the part (strip it back down to the bare surface).
- Return the part to the oven for several minutes (time varies from part to part).
- Bringing the piece partially up to temp will discharge it.
- Now, try re-applying the powder at a lower KV setting while making sure to maintain an average spray distance of 8-10 inches.
Figure 1. Notice the pock marks followed by a crater-like ring surrounding the center.