off-color copper -- issue?

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  #1  
Old 05-02-07, 11:48 AM
ddr
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off-color copper -- issue?

I’ve been putting in some NM 12/2 cable from a new 250’ roll. While the ground and neutral are the normal bright “new penny” copper color, the hot wire’s copper is noticeably darker with a reddish or deep orange tint to it. I’ve never seen this before. Is it anything to be concerned about?

Thanks in advance.
 
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Old 05-02-07, 12:22 PM
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If you rub it with sandpaper, does it shine up?
 
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Old 05-02-07, 02:41 PM
ddr
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Yes, sandpaper will remove the darker tint to reveal a bright copper color, although it dulls the finish (the reddish tint was dark but shiny; the sanded wire it bright but dull).

Is this okay?

What is the coating from?
 
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Old 05-02-07, 09:29 PM
ddr
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Bueller? Bueller?

So is this wire okay to use? Do I need to sandpaper the coating before making a connection?
 
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Old 05-03-07, 08:01 AM
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What you describe is a very thin oxide on the copper; sometimes coatings or oxides just a few millionths of an inch thick can change the color of metals.

This is fairly normal. Just use the wire, as you make connections the oxide film is disrupted and good connections are made.
 
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Old 05-03-07, 08:47 AM
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Yes, use the wire, but I'd buff it up a bit where I was making connections.
 
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