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COPPER PLATING OF CARBON RODS

2003

WE ARE PLATING CARBON ELECTRODES OF SIZES DIA. 7/8/9 MM & 230/330/395 MM LONG WITH 65 TO 75 MICRONS OF ACID COPPER PLATING. WE ARE OPERATING AN AUTOMATIC LINE. THERE ARE NINE PLATING STATIONS AND THEY ARE CONNECTED IN SERIES (NOT IN PARALLEL AS IS NORMAL PRACTICE - i.e. POSITIVE OF RECTIFIER IS CONNECTED TO ANODES OF STATION ONE - THE NEGATIVE OF STATION ONE IS CONNECTED TO POSITIVE OF STATION TWO UP TO STATION NINE.) TO A SINGLE DC SOURCE. DUE TO THE SERIES CONNECTIONS WHEN A CARRIER BAR IS LIFTED FORM ITS STATION THE TOTAL CURRENT BECOMES ZERO AS THE SERIES BREAKS. THE CURRENT REMAINS ZERO FOR 2 MINTS. IN A CYCLE TIME OF 6 MINTS. THIS HAPPENS TEN TIMES IN ONE HOUR.

WE WANT TO KNOW WHAT WILL BE THE EFFECT OF ABOVE ON THICKNESS DISTRIBUTION AND DEPOSIT CHARACTERISTICS.

RAMESH KHARE
C M P - Mumbai, India

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If you are running this line, don't you have the thickness distribution and the deposit characteristics? It's been said many times before, but I'll repeat the litany: a peek is worth a thousand finesses, an experiment is worth a thousand opinions. So I honestly don't understand what you are expecting in the way of wild guesses from people who are not running such a line.

But that series circuit idea sounds like a very poor arrangement that ought to be fixed, for many reasons, including the fact that if two different size parts are in the line it is impossible to plate them both at the correct current density.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2003