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How do you minimize hydrogen embrittlement in copper electroforming?

2003

I have an acid copper plating tank (200 gal). We use it to electroform copper. This means that I will take a model made of wax, paint it with a conductive paint, and plate the form at 1 volt (this minimizes nodules), for 48 to 56 hours to a thickness of .040", pull the model and melt out the wax. Then we are left with a copper shell form of the original model.

My question to the field is that we are having problems with our forms being too brittle and cracking. I have done some research and realize there is a problem with hydrogen embrittlement. Is there a way of minimizing embrittlement in the plating process?

Thank You

Dean Spencer
University of Iowa - Iowa City, Iowa, USA

Acid copper without additives tends to be brittle. Are you using a brightener? Why do you think its hydrogen embrittlement problem?

Russell Richter
- Danbury, Connecticut, USA
2003

I doubt if you are having a hydrogen embrittlement problem with copper. It would be rare if ever. Now you could be having a serious internal stress problem with your copper plate. If you are using a proprietary copper bath, have a long talk with the tech services section of the bath manufacturer. If you are using a home brew, you are the tech services. Your problem very likely cannot be analyzed over the internet, particularly with the modest amount of information provided. Try another bath make up or hire a consultant would be the quickest answers.

James Watts
- Navarre, Florida
2003

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I think I may have found the problem. There are two types of brightener that are used for our tank. One is make up when you start a new tank and the other is an additive. The additive brightener you need a cup of or so once a month or more, which depends on the usage of our tank. My guess is that over time this make up is depleted. So you have to balance this part of the solution. I sent my solution out to the lab to have it analyzed for balance, purity, and hardness. I am waiting on the results. I do not know if they can analyze brightener and make up. Again I am looking at my make up because I found too much brightener can also cause brittleness. What do you think?

Dean Spencer [returning]


- Iowa City, Iowa, USA
2003

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You may have 1-high acid 2-low copper 3-high cathode current.

Khair Shishani
aircraft maintenance - Al Ain, UAE
2004

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I am trying to set up a large tank for electroforming copper. Can you give me any process procedures or guidance?

Thanks,

Paul Hutchins
- N. Ft. Myers , Florida
2004

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What will the mandrels be fabricated from, Paul? If you are starting up a large tank for electroforming, with no prior experience in it, you will have a substantial amount to learn. Are you fully aware of discharge permitting requirements, hazardous waste accumulation permit requirements, etc., before we move to step two?

If you have no experience yet, please start with some of the books on our "must-have" booklist, including the Metal Finishing Guidebook. Good luck.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2004