Your oven may show 200°C. Your part may still be under-cured.
That’s because oven air temperature and part metal temperature (PMT) are not the same especially when parts vary in thickness, mass, and hanging method. Heavy parts heat up slower. Thick jigs steal heat. Poor airflow creates “cold pockets.” Overloading reduces effective dwell time. And large flat panels behave very differently from tubular frames.
Here’s the simple rule: Powder cures only when the part metal temperature stays inside the cure window for the required time. That cure window is defined in the powder TDS not on your oven display.
To confirm cure, you need temperature profiling. Pick a representative “worst case” part (heaviest/densest). Attach the temperature probe on the part metal (not on the hanger). Run the line at normal speed and loading. Record the temperature curve through the oven. Then verify two things: time to reach cure temperature and time spent inside the cure window. If your part mix varies, repeat for 1–2 other part types.
When validating or troubleshooting, use simple checks like MEK rub, cross-hatch adhesion, impact/bend, and pencil hardness always aligned with product requirements and the TDS.
Before buying new equipment, fix the basics: reduce overloading, improve airflow, confirm speed vs dwell, standardize hanging, and profile your worst-case part as the baseline.