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topic 53041

Removing sodium ion form nickel solution

A discussion started in 2009 but continuing through 2020

September 6, 2009

Q. Please help!
Sir I have 1500 liters of nickel solution for the past 10 years; recently we have used sodium chloride instead of nickel chloride, and I have used sodium hydroxide to increase ph of the bath.
Sir I am facing the problem of salt spray failure sir please suggest a way to remove sodium ion for the nickel bath.
Thanks for all who help me.

Aboo Backer
owner of a plating shop - Bangalore, India

simultaneous September 9, 2009

A. I have never heard of a way to remove sodium ions from a nickel bath.
You took the cheap way of adding chloride and now you pay the price. Two possibilities-dump the tank or dump half of it and get by for a few years.
There is no reason to ever have to raise the pH except adding too much acid and possibly-using inert anodes.
Why do you think that the high sodium content is causing the salt spray failure?

James Watts
- Navarre, Florida

September 9, 2009

A. Perhaps I am missing something, but why is the presence of sodium ions causing salt spray failure? Salt spray failure is due to a breakdown of the surface coating - be it a conversion coating or a metal deposit. It sounds like the nickel thickness is wrong, so increase the amount being deposited.

Sodium salts and ions are, as far as I know, impossible to remove from a working nickel bath.

They will affect the conductivity of the electrolyte and it is claimed it affects the stress in the nickel deposit, although I have never seen it. It is also supposed to adversely affect the throwing power, but only to a minimal extent. The high alkalinity that can be generated by adding excess sodium hydroxide can result in porosity and roughness caused by insoluble hydroxides, but this can be overcome by running the bath at a lower pH.

I strongly recommend you improve your general housekeeping - a well kept and well run plating facility would never let this situation occur - I suggest spend some time sorting your shop out.

Carry out a Hull Cell test to see exactly what damage you have caused and then re-assess your plating options- it may not be as bad as you think, but please get your workshop tidied up!

trevor crichton
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK

September 9, 2009

A. Dear Aboo backar,
Cutting the bath is the best option.
In future do not add sodium hydroxide directly in to the bath even for increasing the pH.Best way is to make a slurry of sodium hydroxide with the nickel bath solution; say 500 grms of NaOH+10 ltrs of Nickel bath solution in a 20 ltrs bucket.Lot of heat will be evolved.So take care.Let it become slurry in 5 minutes.Stirr well carefully.Add water to the brim.leave it for 1 hour.throw away the supernatant clear water which will have excess NaOH which will harm the plating bath.repeat this exercise one more time.Then You will get purr nickel hydroxide and can be used to increase pH with out the fear of contaminating your bath with sodium ion!
Take care, Good luck.

t k mohan
T.K. Mohan
plating process supplier - Mumbai, India

September 11, 2009

Q. Thank for answering and helping me.
But sir when sodium ion is present in nickel solution it increase the porosity of the nickel deposit will this not lead to the failure of salt spray test? And can anyone tell me to pass 24 hrs of salt spay test in Neutral Salt Spray, 5% sodium chloride, ASTM B117 [affil. link to spec at Techstreet]
How many microns of bright nickel is required and how many micron of chrome (decorative)
is required to pass this test .Thanking you all for helping . waiting for your answer.

Aboo Backer
owner of a plating shop - Bangalore India

NaCl or NiCl2 for nickel electroplating bath

February 14, 2020 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread

Q. Hello everybody,

I am still working on nickel electroplating :)
I would like to develop a new "home made" nickel bath. For the composition, I have seen in different books and papers some baths are made with NaCl and others are made with NiCl2, for the addition of Chloride in the bath.
What is the difference between NaCl and NiCl2 in the nickel bath? Which is the best and why? NiCl2 is more popular but why sometimes NaCl is used, why?

Could you help me please, let me know if you need more information.
Best Regards

Thomas Perrier
- Berne, Switzerland

February 2020

A. Hi Thomas. We appended your inquiry to this thread, and we're also linking to topic 23867 "Watts Nickel Plating Problem: pH is too low. How to Fix?" to demonstrate that some people think that a lot of sodium is a problem and others don't.

I'm not a nickel plater, but personally I've never heard of using NaCl in making up any kind of nickel plating bath, whereas the Watts Nickel bath (NiSO4, NiCl2, boric acid) has been very widely used around the world for many decades. Unless you are talking about launching a massive R&D effort I don't think it's a good idea to start from other than the Watts bath. Is there some property you feel you can better obtain from another bath rather than Watts?


pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com - Pine Beach, New Jersey
Aloha -- an idea worth spreading


Q. Hello,

Thank you Ted for your reply. I did not know that Na could cause problem in nickel plating, I will investigate in this topic.
About NaCl, I learned that some baths which we call "USA Nickel" ou "American Nickel" are made with NaCl, NiSO4 and H3BO3. But you are right, the most nickel baths are made from the traditional Watts Nickel (NiCl2, NiSO4 ant H3BO3). If somebody use a USA nickel, let me know why this bath is done with NaCl?

My objective is made a nickel bath as a layer under a precious metal. I think a Watts nickel could be used (with additives if necessary).

Best Regards

Thomas Perrier
- Berne, Switzerland

February 29, 2020

A. NaCl will supply adequate chloride, BUT...

All that Na will cause a brittle deposit

jeffrey holmes
Jeffrey Holmes, CEF
Spartanburg, South Carolina

March 4, 2020

Q. Hello,

Thank you Jeffrey for your reply! Na can cause a brittle deposit, Are there any references or papers on this effect of Na on nickel plating?

Thank you,
Best Regards

Thomas Perrier [returning]
- Berne, Switzerland

simultaneous March 7, 2020

A. Here, page 70. http://www.nmfrc.org/pdf/psf2002/090268.pdf

Note, small quantities of Na from addition agents, etc are okay, but using NaCl to replace Nickel chloride will embrittle the deposit.

jeffrey holmes
Jeffrey Holmes, CEF
Spartanburg, South Carolina

March 7, 2020

A. My preference would always be for NiCl2, because NaCl is much less soluble and Na ions can cause stress in the nickel deposit. The reason for adding chloride ions to a Watts nickel bath is to promote anode dissolution, unless you are using sulphur depolarised anodes when, in theory, you do not need chloride ions; this is one of the advantages of nickel sulphamate baths.

trevor crichton
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK

March 9, 2020

thumbs up sign Hello,

Thank you Jeffrey and Trevor for your replies!! Ok, as I understand NaCl is not a good ingredient in a Nickel bath because too much Na leaves a brittle deposit.
In my case, my nickel coating will be under a precious metal and the thickness will be very small (less than 1 micron). The brittleness of the nickel coating should not be a problem but I will follow your recommendation : I will use NiCl2 (not NaCl), it will be better I think.

Best Regards

Thomas Perrier [returning]
- Berne, Switzerland

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