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Q&As since 1989


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Can E-coating be an alternative for zinc galv plating as a rust prevention for metal parts that get powder coated?

I am looking for a substitute or alternative plating process on metal parts for rust prevention that would replace zinc galvanizing and that would still have good adhesion for a good powder coat finish.

Larry Francovich

2006

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Larry, E-coating prior to powder coating parts can produce parts that have better performance than parts that are just powder coated. Will E-coated/powder coated parts perform as well as galvanized and powder coated parts is a question that can best be answered by a set of carefully designed performance tests. The types of performance tests used should look at the range of failure mechanisms you would expect the parts to experience in their normal environment (scratches in the paint film, abrasion of the paint film, resistance to skin oils, suntan lotion, other chemical, weathering and UV light resistance, etc.

You should include some of your current parts with known long-term field performance as benchmarks in these tests. Also, remember that the E-coat process uses a potentially higher performance pretreatment process than your current pretreatment process to limit the contamination of the E-coat tank. You may want to use this process with your current paint system to measure the gain in performance of the E-coat paint layer alone.

Roy Nuss

2006