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Reoxidizing trivalent chrome to hexavalent

We are experiencing difficulty in lowering trivalent levels in our Chrome bath.
Using dummy load 4:1 anode to cathode ratio,six volts. Is there possibly some other Ions that could be stopping the reoxidation from proceeding?

William Bonty
Captive Plating Shop - Grand Rapids, Michigan
2006

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First of two simultaneous responses --

Try a ratio of 10 to 1. You are trying to generate oxygen, not plate. I would strongly consider using porous pot technology. Hard Chrome Consultants in Cleveland, OH used to have a good lower priced unit. This removes most tramp cations at converts the trivalent to hex.

James Watts
- Navarre, Florida
2006

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Second of two simultaneous responses --

You're on the right track, but try anode/cathode more like 100:1.

Jeffrey Holmes, CEF
Spartanburg, South Carolina
2006

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2006

Agree with Jeffrey, the most important is you have to make sure that your anode is clean without heavy yellow film that can protect the current to flow and stop re-oxidation reaction.

My suggestion you should put the anode with current during dummying or electrolyzing to prevent the formation of the yellow heavy film.

Good luck,

Tony Chandra
- Jakarta, Indonesia

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I WOULD SUGGEST YOU TO FIRST ANALYSE YOUR BATH IN ANY LAB AND CHECK FOR TRIVALENT , COPPER ,IRON ETC . IN A. A .S
THEN A REMEDY CAN BE SUGGESTED.
WITH REGARDS,

Ajay Raina
Ludhiana, Punjab, India
2006