The authoritative public forum
  for Metal Finishing since 1989
-----

Alternatives to 'yellow passivate'

My company has parts which are yellow pssivated from a Co. in the UK. We want to move to a ROHS compliant pass that maintains the corrosion protection and the colour of yellow pass. Do you know of any process that gives both?
Many thanks,

Chris Graham
Quality Engineer - Southend, Essex, UK
2007

---

There are no trivalent products or non-chromated products that are utterly indistinguishable from the toxic products they are replacing -- but it is possible to dye the parts to a shade close enough to the natural color of hexavalent chromium to make it look like you are continuing to ship carcinogenic parts :-)

(Sorry to be a 'wise guy'. It's just that it's a strong belief of mine that it's a big mistake to dye trivalent chrome yellow, and I admit to trying to derail any traction the idea is getting).

In general these dyes do reduce the corrosion resistance of the finish a bit, particularly with the TCP trivalent chromates on aluminum. But if you do not need Mil-approved TCP, or if you are referring to the chromating of zinc plated parts, most of the global suppliers can offer you the color you seek and still give you the corrosion resistance you need. Good luck.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2007