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How often to clean the chrome anodes





Q. We have decorative chrome plate 24 hrs running shop, I need to know how often to clean chrome anodes, and which is the best way to clean the chrome anodes?

popat patel
Popatbhai B. Patel
electroplating consultant - Roseville, Michigan
2002


A. Assuming you are using round tin/lead anodes and running 24/7, you should not have to clean your anodes, unless they are dead. By dead I mean no longer for whatever reason, able to conduct current. A healthy anode will have a dark brown coating of lead peroxide, a dead anode will have a coating of yellow lead chromate. Pull your anodes and check them monthly, right after a load comes out. Dead anodes are usually caused by bad contact, nothing a wire brush couldn't fix. Keep your bus work clean.

Steve Delaney
- Ontario, Canada
2002


A. I assume that you have lead anodes. Depending on the use, one can clean anode with wire brush and hot water. If once a week is not possible, do it at least once a month. Why don't you think of switching over to Platinized Titanium and forget about cleaning!

Payal Mag
- Charlotte, North Carolina
2002




Yellow Scale in Hard Chrome Plating Process

Q. We have some yellow scales developing in our hard chrome process. What is the cause and how do you get rid if it?

Thanks for your help.

Steve Kewish
Research - Rochelle, Illinois, USA
August 10, 2015


A. Hi Steve. I'm sure people will need more explanation before they can help. Chromic acid mists will dry to a yellow powder/scale and will spread everywhere if your ventilation system and/or fume suppressant is not working properly. That stuff is toxic, and having that powder/scale around is unacceptable.

Or are you speaking of some sort of yellowish discoloration to the plating itself? A lot more text, and hopefully pictures, will help.

Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
August 2015




Q. As an anode spends time in a bath it will develop a yellow scale.

-What is the scale? Is it residue from the acid bath collecting on the surface of the lead anode? Is it more like a rust, meaning that the amount of scale is a sign of how quickly the anode is wearing?

Steve Kewish [returning]
- Rochelle, Illinois USA
August 11, 2015


A. Hi again Steve. Upon receiving your second posting on this thread, and understanding that you were talking about anodes, we removed your questions from the original thread we had put them on, and appended them to this earlier discussion on the subject. The yellow is lead chromate. If it's only at the solution level, it's probably not a problem; but if the whole anode is yellow, please see Steve Delaney's posting above.

Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
August 2015



August 12, 2015

A. Good day Steve.

Steve Delaney has given very good info regarding anodes.
Yellow deposits on the lead anodes, to the best of my knowledge, indicates they are trending to be passive, as a result of high production, high ASF, trivalent chrome, low anode/cathode ratio, poor bussing contact.
How are you adding the barium carbonate? It does produce the wonderful sludges.
I always made a slurry with water with an addition.
What is your anode/cathode ASF?
What is your plating duration as time?
I have experienced this also, and regularly remove the anodes, one at a time, during daily electrolysis/dummying, and "slide" them up and down on the anode bar to "activate/clean" the anode.
Any evidence of the change in colour/appearance (as dark) of the anode contacts will also indicate poor contact/bussing (heat is generated).
Hope this helps.

Regards,

Eric Bogner
- Whitby, On., Canada.


thumbs up signThanks to all for their input - very helpful.
Steve

Steve Kewish [returning]
- Rochelle, Illinois USA
August 12, 2015


A. Hello. Yellow, crusted chromate scales on lead anodes soak clean well to remove this scale in a solution consisting of 2-4 oz/gal (15-30 g/l) each of caustic soda [affil links] and Sodium Gluconate, typically 8-12 hours). Of course, the source of why the anodes have become encrusted needs to be identified and corrected. One example is chloride contamination.

Stephen F. Rudy
Chem Analytic LLC - East Hanover, New Jersey, USA
March 9, 2019




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