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Q&As since 1989


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Cleaning Copper Bus Bar

Q. I'm trying to find a way to prevent tarnish on the copper busbars that we are cleaning for our factory. I'm using a soak clean, an e-clean and an acid bright dip (sulfuric acid 10%) with a rinse station after each of them. The parts looks good right after unloading from the line but several day after you can see some stains all over the parts. Does anybody have an idea to prevent this issue?

Carlos Rodriguez
Plating Engineer - Juarez, Chihuahua, Mexico
2007

A. Hi, Carlos. They can be kept bright for a good while with a dip in benzotriazole [on eBay or Amazon] or they can be lacquered. Obviously, lacquer must be kept off the joint area, and is only appropriate if the busbars stay reasonably cool -- but I've seen it done in plating shops with very good result.

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

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Q. We are having problem cleaning copper bus bar, we have tried using: soak cleans, electrocleans, and also bright dipping. None of these are working for our process. We are silver or tin plating the bars after cleaning. Parts range from 1/8" x 1" x 12' to 3/4" x 8" x 12' can anyone help use with this issue.
Also, we are having a problem with our silver plating peeling. We noticed since we been having this problem that our anodes in both strike and plating baths are gassing and the stainless steel anodes we use have plating on them. Does anyone have any ideas of what is going on with this?

Thanks,

Amanda Noles-McLain
Electroplater - Manvel, Texas, USA
August 17, 2011

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August 17, 2011

A. Hi, Amanda.

I assume that you've tried soak cleaning and/or electrocleaning followed by a bright dip?

What does the bus bar look like after cleaning and bright dipping? Is it a nice, uniform, bright copper color?

Although insoluble anodes are often used in strike tanks, most silver plating tanks (I believe) use silver anode material.

Insoluble anodes are expected to gas: The rectifier pulls electrons from the anodes and pumps them to the cathode where the surfeit of electrons on the cathode can reduce the Ag⁺ in the solution to metal plated onto the work. But there must be a way for the anodes to gain/accumulate those electrons from the solution, or current would not be able to flow. When you use soluble silver anodes, the silver dissolves from Ag⁰ metal to Ag⁺ generating those necessary electrons. When you use insoluble anodes, the only way for the necessary electrons to be freed at the cathode is by pulling 0^-2 from the H2O of the water and converting it to O or 0₂ which is the gassing you are seeing.

May we also assume that the strike and plating baths have their own rectifiers and there is no chance of the current having been reversed? Because silver is more noble than copper, it can immersion deposit non-adherently on the copper, so the strike tank has to not only be present but to really be working correctly as a strike -- so you might check that.

Regards,

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

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Q. We are using separate rectifiers on the strike and plating. The bus bar after bright dipping has a uniform color. We have tried bright dipping some of our smaller parts, just not the 12' ones which we do the most of. The only problem with a bright dip is that it's not safe for the environment. The TCEQ in Texas will not allow the large bright dip due to environmental issues. So we are looking for something safe with the same or better results for cleaning this bar.

Amanda Noles-McLain
plating - Manvel, Texas, USA
September 27, 2011

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A. Hi, Amanda.

What bright dip chemistry are you using? There are many different chemistries available for bright dipping copper, and a sulfuric acid plus hydrogen peroxide bright dip process may be "environmentally safer" than the bright dip you are presently using, although the bright dip isn't supposed to be in the "environment", it's supposed to be properly kept out of the environment :-)

Vent mode on: I'm against limiting industrial practice to what schoolchildren can safely do at their kitchen table; and it is so foolish to believe, as the TCEQ apparently does, that you can concede the difficult jobs to China but keep the easy stuff. I know a nameplate manufacturer who absolutely did not want to move to China, but the companies he supplied moved to China for their tough stuff, wouldn't put up with waiting for nameplates to come over from the USA and so on -- so the employees all lost their jobs and China got some more. Trying to retain just the easy jobs is the guaranteed way to all of the jobs :-(

Good luck!

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
September 2011

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Cleaning Copper Bus Bars

Q. I am trying to clean some solid and also some laminated copper buss bars to use in an EV restoration. I know it would be better to use plated ones today but these were original equipment. How did the manufacturer finish them so they stayed nice so long. My attempts with various kitchen chemicals prompts immediate oxidation.

Chris Murphy
- Roseland, New Jersey, US
August 16, 2019

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Q. So, using the stand by of vinegar [in bulk on eBay or Amazon] and salt which gets copper spotless, would rinsing and drying be necessary? I would think so. At what concentration would you use this product for a final dip?

Chris Murphy [returning]
- Roseland, New Jersey, US
August 28, 2019