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New at nickel plating, please help!

I am new to nickel plating. I have been trying to nickel plate jewelry as a flash plate for rhodium (the book I'm using recommends it, but tells me it isn't necessary), and I keep getting dark spots where the wire from the negative terminal touches the work! Here's the lowdown on what I'm using, as to clue you in on to what problems I might be having: Using a 10 amp max output Rey electroplater, Krohn nickel plating solution that recommends 70-75 degrees fahrenheit, and I connect the clips to the anode wires (copper, running to pure nickel anodes) and the work, then I turn on the machine, dip the work into the solution, and turn up the amps to about 2 -3 amps. I stir the work around for about 1-3 minutes. What am I doing wrong to get dark spots all over the work? Pretty sure I'm not using too high voltage, as I've even tried 1 volt.

Michael Rodriguez
Jewelry plating - Blythe, California, USA
May 10, 2010

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Michael,
I've been away from production plating for a few years, however I've never heard of a nickel plating solution that operates at room temperature. Most nickel sulphate baths decorative or non - decorative have a temp range of 125-135 degrees F. This temp range varies a little, depending on the supplier. If this bath does indeed run at the temp you say, and temperature is not the problem, make sure the cathode wire is copper, and is kept well below the solution level at all times. Also check your amperage and make sure it is not too high. Good Luck!

Mark Baker
process engineer - Malone, New York
May 12, 2010

Thank you for your response! I will try the temperature you recommended, as the electroplating manual I have also recommends the temperatures you listed.

Michael Rodriguez
- Blythe, California, USA
May 25, 2010