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Nickel Plating (Wood's Nickel Strike and Sulfamate Nickel)

I am trying to figure out the parameters of a nickel plating process. The parts will go in an Alkali Cleaner tank to remove oils, greases and light oxide films. Then a Hydrochloric Acid tank used to activate the surface to accept nickel plating. Third and this is where I need help, they will go in a room temperature Woods Nickel Strike tank. Lastly They will go in a Sulfamate Nickel (Flash) tank at 120-130F for the actual nickel plating.

What I need to know is how to calculate the amps and minutes I need to leave the parts in the Woods Nickel Strike tank. Also I need to know how to calculate the amps and amp-minutes I need to leave the parts in the Sulfamate Nickel (Flash) tank. Any help would be greatly appreciated. Thanks!

Collin Corp
Engineer - Midwest City, Ok, USA
January 21, 2010

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First of two simultaneous responses -- January 22, 2010

As a starting point for the woods strike, try 300 amp minutes per sq ft. Try for 90 amps per sq foot as this will give a better adhesion than lower ASF, and above 110 it falls like a rock so do not exceed 100. The truth is that you need enough to barely give the material a faint color -- all over.
The operations sheet for your sulfamate nickel should give you a fudge factor to estimate the nickel build up.
You have not said how much nickel you need to deposit. Remember, edges plate far more rapidly than the centers, so the calculations are only a starting point.

James Watts
- Navarre, Florida

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Second of two simultaneous responses -- January 22, 2010

First tell us what kind of metal we are plating onto. The Wood's Strike is two to three minutes at 50 amps per square foot on 4000 steel or nickel; but can be less on 1020 steel.

Then tell us an engineering term for "flash". Use no more than 120 F to slow the break down of the SN into ammonium ion. At 20 ASF you should get 0.001 in 60 minutes, similarly, 0.0001 in 6 minutes, so decide what is a "flash" and interpolate those numbers.

Robert H Probert
Robert H Probert Technical Services

Garner, North Carolina