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Iridite Process-cadmium contamination

2002

We are picking up a small amount of Cadmium in our Iridite rinse water. What is likely origin for this substance?

We have acid tanks which have stainless steel liners...could this be the source. We are considering replacement of these tanks.

The contamination has occurred only recently after a number of years of operation.

Richard Cox
- Largo, Florida

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Far more likely that you inadvertently stripped some cadmium parts, believing they were zinc plated.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2002

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By Iridite I assume you are referring to a chromate coating (Iridite 80). I run cadmium plated parts though a Iridite process as well and can tell you that if you leave the part in this chromate solution for too long a time it will start to strip the cadmium off the part. It wouldn't surprise me then to have a little bit of cadmium carry over to the rinse water. I usually leave the part in the Iridite solution for a maximum of 30 seconds and have obtained the best coverage and protection.

Steven Smithers
- Kansas City
2002

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In addition to the above, there is no cadmium in stainless steel.

Bill Reynolds [deceased]
consultant metallurgist - Ballarat, Victoria, Australia
We sadly relate the news that Bill passed away on Jan. 29, 2010.
2002