Rhodium Plating Bath Sediment

What is the black precipitate sediment showing up in the bottom of our Rhodium tank after about 3 weeks of use. We plate 200-300 pieces a day. We keep things extremely clean: ultrasonic, steam, electrocleaner, acid dip and keep our plating baths covered when not in use. They are also inside a Lab hood which is closed when we aren’t plating something. I don’t know that this sediment is causing any problems, but I am wondering if anyone else sees this and what it might be. I’ve been looking into filtering the bath, but absent actual problems don’t know that it’s necessary.


Ruthanne Robertson
Legacy Touch, Inc.

We get the same thing. I don’t know what it is, but it does not affect the plating. I only filter it out when I clean the solution.