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Plating Stainless Steel

2006

Hello
I am setting up a line to plate Stainless Steel. The steps I have come up with are to direct (cathode) clean in a 20 % McDermid Multiprep 506 solution then rinse, then 50 % HCL, then Woods Nickel, then rinse, then nickel sulfamate. Do you have any comments ?

I read your letter 2964 on Woods Nickel.
Is the 1/1 ratio nickel chloride / HCl based on using 31 % HCL?
What would 2/1 ratio nickel chloride / HCl effect?

One bath formula I found was 16 / 32 oz/gal Nickel chloride, 12 / 15 % HCl and 4 oz/ gal Boric Acid.

What info can you share on the boric Acid Formula ?

Thanks for you help

Dickie Martin
ceramics - Laurens, South Carolina

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First of two simultaneous responses --

Strike in 2 pounds per gallon nickel chloride with 1 quart per gallon HCl. Use Rolled Depolarized Nickel anodes, bagged, and remove the anodes when not in use to keep the metal from climbing. (Use S-Rounds in the sulfamate).

Robert H Probert
Robert H Probert Technical Services

Garner, North Carolina

2006

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Second of two simultaneous responses --

The 1:1 ratio was found to best produce the vigorous hydrogen evolution desired over the surface in order to reduce any oxides present and ultimately plate a very thin layer of pure active nickel. In a certain sense increasing the nickel salt content would be like putting more nickel atoms to compete against the hydrogen atoms in the race to reach the surface. Some of them could win and plate before it's totally active with the consequent adhesion problems. Boric is redundant, to say the less, to this bath. Due to its extremely low pH, there is no need for buffering.

Guillermo Marrufo
Monterrey, NL, Mexico
2006

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I've praised Jack Dini's book "Electrodeposition: The Materials Science of Coatings and Substrates" before.

but it has the best treatment of this subject you will find, with real test results for different formulations, current densities, and acid treatments before Wood's Nickel.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2006

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WE WANT TO ELECTROPLATE (BRASS/COPPER/NICKEL) ON STAINLESS STEEL 202 GRADE. WE HAVE ACTIVATED IT BUT PEELING SEVERE. PLEASE SUGGEST THE CORRECT PROCESS.

DEVASISH
PRODUCT DESIGNER - KANPUR, U.P, India
2007

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You may have attempted to activate it, but it doesn't sound to me like you were actually successful, Devasish. Did you do Wood's nickel, or what activation procedure did you do? Thanks.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2007

Thanks Mr. Ted Mooney for you support. The jobs are degreased and pickled in 10% HCl (C.P) but it is turning Black , then we tried with 5% Concentration and it is O.K. We have Plated it with Wood's Strike Bath. 10% HCl and 140-200Gms/ltr nickel Chloride was used. Almost 80% of the Job is still turning Patchy Matt black. Current was kept at 20- 30ASF. The peeling has reduced but not stopped. But the dull black patches on the Job in the Wood's bath is not fully covered in the subsequent plating.

DEVASISH
- Kanpur, U.P, India
2007

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First of three simultaneous responses --

10% HCl for pickling never enough.

John Hu
- Singapore
2007

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Second of three simultaneous responses --

You should not have those black patches after the Woods. It should be a light nickel color with a slight brown cast. It sounds like your Woods has a metallic contamination. You have to dummy it at very low current density overnight. A carbon treatment might also be necessary.

Guillermo Marrufo
Monterrey, NL, Mexico
2007

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Third of three simultaneous responses --

Hai!
I saw your mail. Please do to woods nickel plating proper manner. if you want to plate s.s. material. Material should be mild etched by plating bath, so you first apply 1/3 of plating current in reverse, then you apply direct current, do plating. Peeloff never happen.
Good luck.

P.KARTHIKEYAN
- Bangalore, India.
2007