The finishing.com Hotline: Serious Education ... plus the most fun you can have in metal finishing. Ted Mooney, Webmaster
What kinds of anti-pit and additives for nickel sulfamate electroforming
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
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 Technical Services
Garner, North Carolina
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
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.
R&D practical scientist
Chesham, Bucks, UK
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
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.
R&D practical scientist
Chesham, Bucks, UK
February 19, 2008
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
January 31, 2013
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