| Powder Not Adhering to Workpiece | No high voltage | Clean the spray gun, adjust voltage, or replace the gun |
| | Poor grounding of workpiece fixture or conveyor | Clean all grounding points |
| | Excessive air pressure | Adjust air pressure |
| | Spray gun too far from workpiece | Adjust gun position |
| | Fixture design causes shielding | Redesign fixture |
| | Excessive spray booth ventilation | Reduce exhaust airflow |
| | Insulating layer on workpiece surface | Apply thermal spray |
| | Poor-quality powder coating | Remove insulating layer |
| Insufficient Powder Coating | Low powder output from gun | Replace powder coating |
| | Clogged powder feed line | Adjust pressure, clean or adjust powder feed system |
| | Short spraying time | Clear blockage or replace powder hose |
| | Workpiece geometry mismatches booth | Reduce conveyor speed, add guns, increase powder feed |
| | Excessive powder buildup on fixtures | Recalculate workpiece profile |
| | Low high voltage | Adjust gun position |
| Excessive Powder Coating | High powder output from gun | Adjust high voltage |
| | Spray gun too close to workpiece | Reduce powder feed, adjust air pressure |
| | Prolonged dwell time | Increase conveyor speed |
| | Too many spray guns | Reduce number of guns |
| | Excessive voltage | Adjust high voltage |
| Low Gloss or Discoloration | Overbaking time | Increase conveyor speed or shorten time |
| | Excessive baking temperature | Adjust oven temperature |
| | Contamination from other powders | Clean equipment, use fresh powder |
| | External gas ingress (silicone/paint dust) | Eliminate external contamination sources |
| Coating Surface Contaminants | Improper workpiece pretreatment | Re-inspect and correct pretreatment |
| | Rough workpiece surface | Reprocess: sanding, putty, apply thicker coating |
| | Dirty spray gun/booth/recovery system | Fully clean all components, filter powder, use fresh material |
| | Poor workshop cleanliness | Improve environmental hygiene |
| Pinholes/Craters | Improper pretreatment | Re-pretreat (thorough washing/drying or high-temp drying + sanding) |
| | Contaminated air supply | Inspect/correct, drain moisture traps regularly, install multi-stage filters |
| | Improper phosphating | Control phosphating film adhesion |
| | External dust contamination | Clean system, use clean powder |
| | Workpiece defects | Inspect, replace, or apply conductive putty |
| Poor Adhesion/Mechanical Strength | Insufficient curing temperature | Adjust oven temperature (consider workpiece thickness/heat absorption) |
| | Short curing time | Extend curing time |
| | Improper surface treatment | Inspect and correct |
| | Excessive coating thickness | Reduce powder application |
| | Severe overbaking | Strictly control curing parameters |
