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RoHS Gold or Yellow MIL C 5541 class 3

2007

I have special request from a customer to meet the MIL C 5541 class 3 in a gold or yellow RoHS compliant chem. film coating. I'm not having any luck with my current suppliers and have started questioning if such a coating exists. Although Alchrome Tri- Tec claims to have a product that meets this requirement, I'm being told it's not the same as the gold or yellow we know with the hexavalents.

I don't seem to have problem finding vendors who do the clear RoHS version but the yellow is another story.

Help

Darren McMullin
Process Compliance Manager - Canada

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2007

Somethings gotta give. The only RoHS-compatible Mil-C-5541-compliant coating is TCP because that's the way Mil-C-5541 is written. And TCP is very thin and for that reason non-dyeable. You need to give up one of the following: RoHS compliance, Mil-C-5541 compliance, or color. My second choice to surrender would be Mil-C-5541, but my first choice would be color.

Remember that the yellow color you're striving for was not dye -- it was the natural color of toxic, carcinogenic, hexavalent chromium. Explain to your customer that, besides the difficulty, you are not comfortable with the risk of attracting regulatory and activist attention by deliberately dyeing the parts to make them look carcinogenic, and see if s/he can come around to the same mindset.

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

P.S.: Kim Price, marketing manager of Luster-On and one of the four TCP licensees explains the situation with yellow TCP in our podcast interview with her.