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RoHS compliant direct alternative of yellow zinc searched

2006

Dear All,
Yellow zinc and Dacromet are fasteners finishing in the company I work for. With the RoHS directive coming sooner or later to our industry as well, we have already started searching for a "direct" replacements. It means the new ones should be as much similar from technical and commercial point of view to current ones as possible. For Dacromet we have chosen Geomet 500A. Was it a right choice? For yellow zinc we are still searching. What are your suggestions? What do you expect to be a standard replacements for these two finishings (e.g. in automotive industry)?

Beata Krehel
Bombardier Transportation - Siegen, NRW, Germany

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Suitable trivalent chromates are by now widely available, Beata. The thing is, they are all proprietary, and some differ from others. The situation from the end user's perspective is you need to specify that only trivalent chromates be used, you must specify the required corrosion resistance, and if there is anything unusual about your particular application (conductivity required, the chromating to be followed by powder coating, etc.) you must be careful that the proprietary trivalent chromate system that the shop has specified takes those requirements into account.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2006