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Ted Mooney, P.E. RET
Pine Beach, NJ
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for Metal Finishing since 1989
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Nickel sulfamate electroforming: anti-pit & additives
adv.
Q. I am considering electroforming nickel in a nickel sulfamate solution for a high temperature (600 °C) application in a heat exchanger, but I have read about sulfur embrittlement causing a severe degradation in the mechanical properties of the nickel at elevated temperatures.
Can anyone suggest what steps can I take when creating my setup to get the best possible high-temperature performance in the nickel? Are there other bath chemistries I should use instead? Thanks.
- Los Angeles California
June 28, 2021
⇩ Related postings, oldest first ⇩
Q. I'm not familiar with the nickel electroforming process, may I ask: Is SNAP-AM the most suitable anti-pitting agent for nickel sulfamate bath? What is the chemical structure or type of SNAP-AM? Also, what kinds of additives are suitable for this bath? sodium saccharin? any other suggestion?
Thanks so much.
Queenie [last name deleted for privacy by Editor]plating shop - Hong Kong
2004
A. SNAP-AM is the commercial trade name for a surfactant product used in Barrett Nickel Sulfamate Plating Solutions. The A stands for air agitation, the M stands for mechanical agitation - so you may use either with out foaming. For electroforming hold the surface tension down under 32 dynes per cubic centimeter. Be aware that when/if you carbon treat that the carbon takes out the surfactant first, before it touches the particular organic contaminants you are trying to remove.
Saccharin increases compressive stress. Do not use saccharin for electroforming.
Do not use any additives. For electroforming you want a very clean simple solution of Nickel Sulfamate and Boric Acid (Solubility a function of temperature). Chloride and/or Bromide are sometimes used to aid in the dissolving of the anodes. If you use S-Rounds you may only need 1/2 oz/gal Nickel Chloride, try it without chloride first, then if the metal goes down, then put in 1/2 oz/gal,. Chloride causes increase in tensile stress so keep it low.
Robert H Probert
Robert H Probert Technical Services
Garner, North Carolina
2004
First of two simultaneous responses --
A. SNAP is the acronym for sulfamate nickel anti pit that dates back to the Barrett process. This is used for plating with a low level of agitation. SNAP-AM is for air or heavy mechanical agitation. You can search this site as the generic version has probably been discussed in the past. BUT, where do you find out how to control the amount for optimum results. I learned a long time ago that it is not worth reinventing the wheel to save a few dollars a year. I would buy the original or a good equivalent from a reputable vendor that can also provide technical service when needed. If your time is worth anything at all, it is cheaper in the long run.
James Watts- Navarre, Florida
2004
Second of two simultaneous responses --
A. Nickel electroforming is, in principle, reasonably easy, but you need to understand some fundamental concepts. I would say that there is no "best" wetting agent for electroforming, as different wetting agents can have varying effects on the final deposit. You may want to alter the stress in a deposit and this can be done by using the correct additive. Sodium saccharin is an excellent brightener and hardener for nickel, but it can affect the stress. I would suggest you speak to a supply house and tell them exactly what you need and let them supply a well tested system. It will save you a lot of time and effort, as well as money in the long run.
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2004
A. Thank you for all your reply and suggestion. I have asked some local vendors what kind of additive is suitable for the nickel sulfamate bath, and they told me that they would mix up the nickel sulfamate with the optimum amount of additive before selling to the customers. Actually, my project is related to the micro-electroforming of nickel,and I realized that the macro-scale is different from the micro-scale, may I ask that what aspects of micro-electroforming I need to take much more attention, or just based on the macro-scale procedure...thanks for giving me kind help!
Queenie Yuen- Hong Kong
2004
A. Your important aspects will be the surface tension and viscosity of the electrolyte, the flow rate around your mandrel and the cleanliness of the mandrel. It is important to get as lower surface tension as possible and to have a low viscosity. Do not exceed 70C with sulphamate nickel or it will become increasingly more stressed. You may well get some more reliable tips if you look up MEMS technologies on the Internet.
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2004
Q. Dear Sir,
I am also a new hand in the nickel electroforming.
As Doc. Trevor Crichton said, my important aspects are the surface tension and nickel flow rate.
If I use saccharin,the result is increasing compressive stress, but the sorption is very well.
If I do not use saccharin, the result is no increasing compressive stress, but the sorption is bad .
So could you suggest me how to do?
nickel plating - Hong Kong, China
February 19, 2008
Q. First: I am a novice at maintaining a nickel bath. The gentleman retired who took care of the baths. Recently we had a problem with contaminated rainwater getting into one of our baths. We could not produce a good part. Pitting excessively. Working with MacDermid they suggested carbon filtering with peroxide added. This stripped all of the anti-pit from the bath. We have a 600 gallon tank. My question is how many gallons or liters of Snap AM should I add to the bath.
The bath stag's at 9.36 dynes now.
For my verification what formula is used with a 5 ml Stag.
Any suggestions will be greatly appreciated.
Supervisor, Technologist - Marietta
January 31, 2013
Nickel sulfamate formula for D-I-Y plating
Q. I am working on a sculpture project which involves layering of alloys on top of a football sized optically clear resin orb. I have successfully dipped these orbs into a copper acid bath and built up some good thickness of material. I now want to make a nickel sulfamate bath and would like a formula with amounts to fill a 10 gallon container. I have a good sized rectifier.
The idea is to eventually have a dozen or so layers of differently coloured alloys (using thermal spray gun applications as well) and then sand back down to the optically clear resin, exposing the layers of metals, like the rings on a tree...
Many thanks in advance!
Nei
neilcliffordstudio.com - Toronto Ontario Canada
November 11, 2016
sometimes on
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free pdf is currently available from academia.edu
A. Hi Neil. I'm not sure why you want to do your own formulation, but you can find the concentrations and other data in the Metal Finishing Guidebook .
One more thing you'll probably need is a wetting agent; I suppose you could try baby shampoo. Good luck.
Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
November 2016
Q. Hello Ted, thanks for your reply. I have downloaded the Metal Finishing Guide Book, which I can see will be invaluable as I move forward with my sculpture project. However, I did not see a nickel sulphamate solution in its many pages.
I just need concentrations, or amounts of nickel sulphamate, nick. chloride, and boric acid for a 10 gallon tank.
The reason I am making it, is because I believe it to be considerably cheaper than buying a [brand name deleted by editor] mix, which costs many hundreds of dollars.
Neil
- Toronto, Ontario, Canada
November 13, 2016
November 2016
Hi. It's there on page 295 of the book (which seems to be p. 301 in the app's search engine). Good luck.
Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
November 15, 2016
Thanks Ted.
I was told that one can use 300 series stainless anodes in a nickel sulfamate bath.
Would that work, in your opinion?
As per the formula on page 295, it states the nickel chloride g/L is 0 to 22. I find this confusing, suggesting that one can add none or up to 22 g/L.
If my intention is to build a thick layer of nickel, what would be the ideal mix?
All help is most appreciated.
Again, this is for visual effect only, nothing to do with industrial use.
Thanks.
Neil
- Toronto Ontario Canada
A. Hi again. I think you probably could get away with stainless steel anodes, but then the nickel concentration will decline as you plate; the ideal for your situation is probably sulfurized nickel anodes. A big advantage you have over industrial users though is the "one-off" nature of your need, whereas industrial platers must maintain an equilibrium process (concentrations of everything remaining stable over time despite heavy use).
Although I'm no sulfamate nickel expert, and many people have spent significant portions of their careers on just that one subject, I don't think you need any chloride (one of the important roles of chloride is to promote anode corrosion) -- probably not needed with sulfurized nickel anodes or stainless anodes. If you end up using pure nickel anodes because of availability, then some chloride is necessary if you want the anodes to corrode for stable nickel concentration.
Try to befriend a nickel plater in the Toronto area; it would make things a lot easier :-)
Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
November 2016
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