Powder Coating Troubleshooting Tips
Problem | Cause | Remedy |
Adhesion Poor | 1. Inadequate cleaning or pretreatment | 1. check pretreatment equipment and chemicals |
2. Under cure | 2. Increase oven temp and/or time in oven | |
3. Film thickness too high | 3. Reduce thickness by lowering voltage or shorten spray time | |
Chipping | 1. Powder not fully cured | 1. Check pretreatment equipment and chemicals |
2. Coating thickness too high | 2. Reduce thickness by lowering voltage or shorten spray time | |
Corrosion Resistance (Poor) | 1. Inadequate cleaning or pretreatment | 1. Check pretreatment, equipment, and chemicals |
2. Under cured | 2. Increase oven temp or dwell time | |
Cratering | 1. Contamination with other powder | 1. Clean the system and start with virgin powder |
2. Inadequate pretreatment of substrate | 2. Check the pretreatment | |
3. Contamination with incompatible materials from spray area (i.e. silicone) | 3. Check for presence of incompatible materials | |
4. Oil or moisture in air lines | 4. Check air lines. Install filters if necessary | |
Flow (Poor) | 1. Curing temp too high | 1. Reduce oven temp and/or time in oven |
2. Preheat oven too high | 2. Reduce pretreat oven temp and/or time in oven | |
3. Coating thickness too low | 3. Increase coating thickness by using a higher voltage, longer spray time, or more dense powder cloud | |
Out-Gassing | 1. Air entrapped in substrate (i.e. castings, sandblasted parts) | 1. Preheat above curing temp and coat hot |
Gloss Difference | 1. Curing temp too low or too high | 1. Increase/decrease oven temp and/or time in oven |
2. Contamination caused by other powders with different flow or gel characteristics | 2. Clean guns, hoses, and hoppers, use virgin material | |
Impact Resistance/Flexibility (Poor) | 1. Under Cured | 1. Increase oven temp or increase dwell time in oven |
2. Poor cleaning or pretreatment | 2. Check pretreatment equipment and chemicals | |
3. Film thickness too high | 3. Reduce film thickness by adjusting application equipment | |
4. Change in substrate thickness or type | 4. Check substrate with supplier | |
Off Color | 1. Improper oven exhaust | 1. Check exhaust fans |
2. Bake time too long or too short | 2. Adjust line speed and/or temp | |
3. Oven temp to high or too low | 3. Adjust oven temp | |
Opacity (Poor) | 1. Coating thickness too low | 1. Increase coating thickness by using higher voltage, longer spray time, or more dense powder cloud |
Orange Peel | 1. Warming up of the coated material is too slow or too fast | 1. Check curing cycle and curing oven, if necessary, contact your powder supplier |
2. Heat damage of the powder | 2. Replace the powder | |
3. Film thickness too low | 3. Increase the thickness by raising voltage or lengthen spray time | |
Pencil Hardness/Abrasion Resistance (Poor) | 1. Under cured | 1. Increase dwell time or temp in oven |
Penetration )Poor) | 1. Powder Delivery | 1. Adjust powder delivery |
2. Poor grount | 2. Check ground | |
3. Improper spray pattern | 3. Select proper deflector or use suitable barrel and cover (consult your equipment supplier) | |
4. Voltage too high or too low | 4.. Adjust voltage settings so powder builds on pans edges and leading surfaces do not repel powder from corner | |
5. Poor gun placement | 5. Adjust gun position so powder cloud has a direct path to recess area | |
6. Powder to fine or too coarse | 6. Consult powder supplier | |
Pinholing | 1. Coating thickness too low | 1. Increase coating thickness by using a higher voltage. longer spray time, or move dense p9wder cloud |
2. Curing temp too high | 2. Decrease oven temp and/or time in oven | |
Sags | 1. Coating thickness too high | 1. Reduce coating thickness by using a lower voltage, shorter spray tiem, or less dense powder cloud |
2. Cure temp too low | 2. Increase oven temp | |
Soft Surface | 1. Curing temp too low | 1. Increase oven temp and/or time in oven |
2. Contamination with an incompatible power, especially a thermo-plastic | 2. Clean guns, hoses, and hoppers, use virgin materials |