Determining between AL, CU and Cu coated AL

[Jeffrey]

I have and old home with knob and tube wiring. I need to replacew and outlet with a new one. How do I tell what kind of wiring I have? Would scratching the bare wire clue me in to which type it is? Is AL more pliable than CU? Just looking for advice

Thanks,

Jeff

[Mike44]

It definately would. Aluminum (Al) wiring will be silver in colour and copper (Cu) will be copper in colour. You may have to scratch off any oxide that's formed on the bare metal if the wiring is fairly old to see what you have. If you do have aluminum wiring, make sure to replace the outlet that is rated only for aluminum - you can not use a copper rated outlet there because these two metals can not come in contact with each other without a barrier (such as lead for example). The upper and lower screw tabs on the outlet will let you know what kind of wiring that outlet is rated for. Look for etched letters saying either Al or Cu, or in some cases both - Al/Cu.

There may be one other one other thing - copper coated aluminum wire. I'm not too familiar with that on codes and stuff, so maybe let one of the other guys answer that about how to determine if you have that and what to use if you do have that (it may say on the printed text on the wire sheathing though).

Mike