At school, my Chemistry teacher for the last two years or so was a fairly young woman (can't remember her name?) - but we were doing something in the lab when she noticed her engagement ring had turned bright green, and her boyfriend had claimed it was 24 carat!

She wasn't amused!.

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Trouble is, 24 carat gold is "worthless" for jewelry as it is so soft that rings easily bend out of shape and prongs that are supposed to hold gems in place don't. If she'd known anything about jewelry, the boyfriend's original claim should have been suspect!

Ring alloys are usually 10K for strength. Gold chains are often 18K.

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Dean Huster, Electronics Curmudgeon
Contributing Editor emeritus, "Q & A", of the former "Poptronics" magazine (formerly "Popular Electronics" and "Electronics Now" magazines).

R.I.P.

 

Perhaps it wasn't 24 she'd been told (it's MANY years ago), but she was certainly very unhappy at how green her ring turned in a single lesson

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silver and copper both oxidize badly which degrades the connection. Good connectors use a gold plated copper, cheap ones use tin plated copper which is pretty good for durability (way better than bare copper).

 

I thought better rings were alloys of gold and silver. Anything that turns green has copper in it, which would be cheap alloy.

 

I think that was her concern.

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PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

But if you loose conductivity with a silver contact, you can burnish it.
Do this with a gold contact and you wear away the thin gold coating.

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http://malfam.googlepages.com/

 

Why would you burnish a gold contact?.

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PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

How true, why would you need to as that defeats the purpose of using gold. At any rate I never burnish contacts, I have found a pencil eraser to be very effective in cleaning contacts.

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Wouldn't that be considered 'burnishing'?.

As you say, pencil rubber is quite good for it - so is a tiny squirt of WD40, and inserting the connector a few times.

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PIC programmer software, and PIC Tutorials at:
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I think of burnishing as something more abrasive, erasers seem to be less evasive on the metal coat, yet are still effective.

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Pay it forward.

 

I never do, but I have seen someone doing it.

I would think that the eraser would be the most abrasive.

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A Q-tip dunk into alcohol cleans as well. (Not whiskey! Too expensive)

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Proper Planning Prevents Piss Poor Performance

 

Many erasers have sand in them and will destroy the plating on a contact. The white ones for "artists" do not have the abrasive.

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Uncle $crooge

 

See this link Resistivity - Wikipedia, the free encyclopedia for specific resistance of metals, you would be able to decide. due to cost effectiveness, they use copper and Aluminum with some protection against corrosion. It is economical to use aluminum (in fact ACSR) for power line feeders

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Regards,
Sarma.