Re: [Phys-l] copper cleaning

[brian whatcott <betwys1@sbcglobal.net>]

On 4/4/2011 4:58 AM, Anthony Lapinski wrote:
> I have a tarnished solid copper pole, about 1.5 cm thick and 40 cm long. I
> hope to use it for heat/electricity demos. What is the best way to make it
> look shiny? I have searched online and found a variety of ways, from using
> vinegar to steel wool. Thought I'd ask the experts first before I try
> anything. And once cleaned, what's the best way to store the pole to
> preserve the surface? Wrapped tightly in plastic?
>
> ___
The conservator's way with oxidized specimens is cathodic stripping.
Attach an electrode at some point.
Provide a counter electrode such as a strip of stainless steel strip.
Connect the specimen to the negative pole of a low voltage supply.
Connect the counter electrode to the positive pole.
The supply could be a battery of a few volts or a battery charger.
Render the water electrolyte slightly conductive with an alkaline solution.
Bicarbonate of soda, or some such; washing soda has been popular in the 
past.
To preserve the bright surface,  a dip in electroless nickel would keep
 it bright, or a coat of silver polish.

Brian W