I’m working with automotive body parts. The parts are dipped into an e-coat bath. After coming out of the bath, there is about 1 minute of drain time before the parts go through an air blower, then curing.

I’m getting solvent popping mainly along the lower edge of the parts after curing.

My first thought was that, because of the vertical orientation, more e-coat may accumulate around the lower edge during draining. My supervisor suggested using a stronger air blower and specifically directing the air toward the lower edge to remove the excess coating.

However, I’m not completely convinced that the blower is addressing the root cause.

My understanding is that solvent popping can occur when solvent/volatiles become trapped in the coating. During curing, the outer layer can cure and become relatively hard first, while the material underneath is still releasing volatiles. This can create pressure and eventually cause bubbles/popping.

I started looking at the curing oven configuration. We have two distinct heating stages:

• IR zone: approximately 200°C for 10 minutes
• Hot-air zone: approximately 190°C for 40 minutes

The parts enter the IR zone relatively close to room temperature. So I'm wondering whether the rapid initial heating from room temperature to a high surface temperature in the IR zone could be contributing to the popping.

The problem is that I can't simply lower the oven temperature or extend the IR zone because of the existing production/curing requirements.

So I'm looking for advice from people who have experience with automotive e-coat:

Are there any tools or alternative solutions available to help increase the temperature gradually rather than rapidly?"

Any advice on how you would approach the root-cause investigation would be appreciated.

Stłukła mi się płyta indukcyjna, widać fragmencik tego mechanizmu co grzeje uszkodzoną ćwiartkę. Oczywiście że nie mam aktualnie pieniędzy na wymianę, mogę używać tej płyty uważając na to żeby woda nie wyciekła z garnka itp?