Autophoretic® and zinc chromate coating

Autophoretic® coatings are more environmentally benign but, to my understanding, they are barrier layer coatings rather than sacrificial coatings. Once they are scratched away, no protection is offered. Think of them as paint, I guess.

Dear Mr Mooney,

I think what Mr Rewade means that he is already using Zinc Chromate rich paints and wants to use E- Coat instead. The answer would be of interest to me so I'll look forward to your renewed response.

Hi KV. I did take it that he was currently using zinc chromate rich paints. But, he said 'Autophoretic®' rather than 'e-coat' so I assumed he was looking at going to an Autophoretic® system.

I may be right or I may be wrong, but I believe that Autophoretic® coatings do not contain zinc and do not offer any sacrificial protection like zinc-based paints and coatings. I was only involved with them on one project, where we considered replacing zinc plating with Autophoretic® coatings on some quick-connect hose couplings. We decided that the component was so susceptible to scratching from being knocked and dragged around that Autophoretic® coatings (or any non-sacrificial coating) was not a good choice.

Just chatting here, rather than doing solid investigation, I express my concern that a non-sacrificial coating on a flexing component like a spring, and one which is held in place by shackles which could abrade the coating, might be a problem. But it wouldn't surprise me to find that auto manufacturers have gone to Autophoretic® or e-coatings on leaf springs either because I think I've heard that.