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What finish shall I ask for to get RoHS compliant zinc chromate?

2005

In the past when we needed ~96hr salt spray resistance on cold rolled steel, we called out: Zinc Plate per ASTM B633, 0.0002 in. min., Type II passivation, yellow.

With RoHS legislation soon to ban the presence of CrVI on our products, I want to be able to ask for high resistance to corrosion, yet allow clear color. I'm afraid if I just ask for "clear" I'll get a compromise in quality and robust performance. (Thinner coating) If I remove the color designation, I could get other colors and these will not be acceptable to in our current product lines. I also need to avoid getting an electrically insulating layer.

Can anyone suggest how I should modify our existing drawings?

Thanks in advance for your time.

Beth Kujan
Telecom OEM - Whippany, NJ

If you cannot find a spec you like, then you need to make your own. Specify zinc with clear or yellow trivalent chromate, no sealers or organic topcoats. Pass 96 hour salt spray to white corrosion products on significant surfaces.

Gene Packman
process supplier - Great Neck, New York
2005

August 14, 2010

Hi,

I agree with Gene except to add that you needn't necessarily "throw away" the standard spec, which may incorporate well thought out and lengthy provisions, just because it's not perfect. You can also say: "in accordance with specification x except chromate must be RoHS-compliant trivalent" (or whatever requirements you wish to add).

Regards,

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

October 25, 2010

Hello all,
Please let me know how to make a note for the painting/coating person about zinc plating with blue pasivation in my drawing.

Regards,

Dheerendra AV
- Bangalore

Hi,Dheerendra

As you can see, we appended your inquiry to a thread which may answer it. But if you have further questions, please continue.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
October 25, 2010

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