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Nickel Plating Stainless Steel

I am trying to nickel plate 304 SS washers in a nickel sulfamate bath. I am cleaning in a ultrasonic with Alcojet then activating in a solution of 10 % H2SO4 AND 1 % HCL. The parts plated and looked ok. I plated 75 micro-inches. The plating peeled in the tape test. The Macdermid people said I need to strike the parts first in a Wood's nickel bath. Is this correct ? We have another empty tank we used for nickel sulfamate. It has S nickel rounds in titanium baskets. Can I clean the tank and s-rounds up and use it as a Wood's nickel bath?

Thanks

Dickie Martin
- Laurens, South Carolina
2005

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Yes, it is correct what MacDermid said - you need a nickel chloride strike. IF you use s-rounds in the NiCl strike you will too fast increase the nickel metal content and the strike will become a regular plating bath. Use Rolled Depolarized Oval Nickel Bars,bagged, and take out of solution when not in use to prevent the metal from climnbing beyond an INEFFICIENT STRIKE INTO AN EFFICIENT PLATING BATH. Between the strike and the sulfamate do not hold it up in the air and gaze, move fast. Robert H Probert Robert H Probert Technical Services Garner, North Carolina Yes your supplier was correct. A Wood's Strike is the generally accepted method to plate most metals over stainess steel. People who do not use this type of strike may get adhesion some of the time, but the adhesion is poor and inconsistent. Gene Packman process supplier - Great Neck, New York The tank is fine. Use rolled depolarized nickel for anode material. If you use SD nickel rounds you will eventually have to dump and rebuild the tank as well as you will have gradually increasing grief. You will have to add another set of rinse tanks or the high chloride content of the strike tank will mess up your nickel tank chemistry (carry over). I found that using a nickel concentration on the low end of the recommended range and a HCl concentration on the higher end worked best for me. For some reason, as the nickel content went up it would grow at a faster rate. You can take the anodes out and store them (when not in use) in a bucket/tank of water and you will basically not have a nickel concentration growth that will require periodic partial dumps. A strike tank can last for years with minor care if operated correctly. James Watts - Navarre, Florida Dickie, There is no objection from me, provided you use the correct approach to cleaning anything you will be (re) using when making up the bath. I take it you are a MacDermid customer? If so they should be more than glad to assist you in preparing the ni. strike bath. Does your customer require an acid cu. flash or plate prior to the sulfamate plate? Also, there are probably more inexpensive ways to cleaning your s/s washers than Alcojet. Good Luck! Michael Null barrel plater - Methuen, MA, U.S.A. If I were you I would listen to the experts. I wholehearted agree with MacDermid, if you are doing SS then you need to strike first. Watt's^Wood's nickel is a good universal strike that will cater for for your needs. So, yes, clean that tank out and get a Watt's ^Wood's nickel in. Have a bit of a play before you use it in anger. You will need to get the chemistry right and the operating conditions sorted for your parts. If in doubt ask the nice people at Macdermid, I bet they will be very helpful and help you through the early stages of using a new process. Brian Terry Aerospace - Yeovil, Somerset, UK

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Whoa !, Be careful. Brian Terry mistakenly used the word Watts for Woods. Watts will NOT activate stainless steel, Woods will. That is why I always say Nickel Chloride Strike, two pounds per gallon nickel chloride and one quart per gallon (up to 2) HCl.

Robert H Probert
Robert H Probert Technical Services

Garner, North Carolina

2005

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2005

Robert,

Absolutely right, must have had a bit of a mind blank on that one, I did mean Wood's. You know what it's like, head in the clouds, read your response, brain substitutes correct wording for what was actually typed.

Do apologise for any confusion caused.

Brian Terry
Aerospace - Yeovil, Somerset, UK

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2005

We also use Macdermid chemicals in our plating shop. But anyway,we found a way to Ni plate SS without using a Woods Strike,we use our regular cathodic acid (beefed up a bit) and we have done this many times successfully. Here is what we did, Maybe it will work for you? We have a 250 gallon tank,we use carbon graphite anodes(8 alltogether-4 to a side) we use one of MacDermid's products 25 gallons of Metex LDA,6 gallon of Hcl,and finally 30lbs. of ammonium bi-fluoride,we run it at room temp and like I said we have plated Ni on SS very well,no blisters,we get excellent adhesion,I'm not telling you what to do but maybe give it a try,works well for us!

Regards,

Brian C. Gaylets
- Scranton, Pennsylvania

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2005

Hi there,
If you want to be sure that you will have no adhesion problems with plating on SS, a nickel strike layer is a must.

Sara Michaeli
Tel-Aviv-Yafo, Israel

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2005

Sara I would have to totally disagree with your statement. If you read my above response you will see that we have plated Ni on SS many times successfully. We put our product through a very vigorous bend test and we also sent them to be salt sprayed,and we have 100% adhesion,no peeling,no cracking,and no brittleness.


Regards

Brian C. Gaylets
- Scranton, Pennsylvania

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2005

Brian,
You use a cathodic acid instead of a Nickel strike solution. It gives a similar effect of activation. Anyhow a strike is considered to be more safe on ALL type of stainless steel.

Sara Michaeli
Tel-Aviv-Yafo, Israel

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Dear Martin,

I think it is unfair to question a reputed manufacturer like MacDermid

Shafiuddin A. Mohammed
metal coating shop - Dubai, United Arab Emirates
May 17, 2009

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Ed. note: Agreed, Mohammed, that we don't criticize any company or individual on these pages. But I don't see any criticism; it seemed that Martin merely mentioned his process supplier for clarification. But double checking / asking for a 2nd opinion is not the same thing as criticizing.