E-Coat on new fenders

The company I work for has done ecoat for the electrical industry for decades and not all ecoat's are equal. The substate prep will determine if its good or not and you cannot see that or trust it was done well. I would sand off and prep from bare metal for best results unless its used in non-visible areas (floors, etc.). You cannot trust thickness gauges because ecoat is designed to be extraordinarily thin due to the electrical process of bonding (like powdercoat but in a paint bath that is electrically charged). Also you do not know if the ecoat base material is not a low-cost option like a simple acrylic vs. something more durable.

If you could verify the ecoat process, you will want a substrate pretreatment of a phosphate (iron, zircon, etc.) built up with a binary paint that is approximately 50% urethane acrylics and 50% epoxy under a very high DC voltage. This combo is a solid base to build on with only minimal scuffing. It is unusual in the world today.

Good luck,
RGAZ