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Why plating on heater without connecting - negative (black wire)

May 19, 2009

Dear Sir,

I saw in my 3N solution when I connect + positive (red wire) to anodes heater starts to become gold on it.

I have not yet connect - negative(Black wire.

Same thing happen in electrocleaning.

If I connect black wire with an object in solution more plating speed
raise on heater.

Every time I have to remove heater, before it was not like this.

Please advise

Dipen Pattni

Dipen Pattni
jeweler/goldsmith - Dar-Es-Salaam, Tanzania

I am not sure of exactly what you mean, but my guess is that you have a metal heater that is grounded and thus is serving as a cathode as well as your parts. Go to a quartz heater or if you can afford it, a teflon coated heater.

James Watts
- Navarre, Florida
May 20, 2009

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First of two simultaneous responses --

Hi,
It sounds as though the -ve terminal of the power supply is grounded and is then connected to the ground of the heater. If so, the remedy is to ensure that the not grounded but floating.
Harry

Harry Parkes
- Birmingham, UK
May 22, 2009

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Second of two simultaneous responses --

You have stray currents. Check your tank is electrically insulated

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
May 22, 2009

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May 22, 2009

Hi,

I'm using S.S heater in 3N solution and I found if I unplug that heater and I connect + positive (red wire) to anodes nothing gets problem.

I had order glass and SILICA heater.

Secondly my Ni and flash gold tank doesn't get any problem I had installed same extension wire for heaters.

First time after 15 years I face this kind of problem.

Is it because of new rectifier I installed if yes then why it happens in 3N and electrocleaning, why not in Ni and flash gold.

Thanks

Dipen Pattni
jeweler/goldsmith - Dar-Es-Salaam, Tanzania

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Repeating what I and other contributors have said the -ve connection appears to have been grounded. This is unusual as electroplating power supplies normally have both +ve and -ve outputs floating (not connected to ground). This is why you do not have problems with your other baths. The -ve lead on your power supply may have been grounded by the manufacturer or the engineer installing the plant. Suggest that you contact an electrician who understands these things.

Harry Parkes
- Birmingham, UK
May 27, 2009