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Hex Chrome in Zinc Chromate Plating and RoHS compliance

2005

Most of the forums have said any and all Zinc Chromate finishes using Hex Chrome are not compliant to RoHS. Since RoHS allows 0.1% hex Chrome by weight, I am curious to know if the amount of Chrome has ever been quantified. Does anyone have analysis data or hand book data which tells how much Cr is in the gel coating? Does anyone have analysis data for how much the Zinc Chromate plating actually weighs.

If you calculated the Chrome weight over the total plating weight is it less than 0.1%? If not, what about increasing the Zinc thickness.

Thanks in advance,

Kevin Underwood
Barry Controls and Vleir - Brighton, Massachusetts

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Hopefully someone will answer you, Kevin, but it's not something I personally would spend time researching because it's time to stop using hexavalent chromates unless the application is truly extraordinary. Building and shipping parts that have a toxic carcinogenic gel on them is no longer a good idea considering that the recently developed, greatly improved new generation of trivalent chromates make it no longer necessary in most cases.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2005