Be careful buying used cable. Like "mete" said, you can get some with a "Plastic" core. A few years ago, a guy gave me a section of cable and I proceeded to put in my forge to burn off the oil. Well, after a minute or two, I noticed this crap bubbling out the end of the cable. Made a heck-uva mess in the bottom of my forge.
Toopid me didn't check it and had to re-line my poor old forge. Can I get a big "DUH" here?
Robert (Who occasionally has brain-far*s)
Avatar is "Busta" (RIP 8-12-15), a rescue. He was my shop dog and a good buddy.