I had a long length of copper ground wire that was still in good condition other than the many kinks and folds caused by the way the wire had been stored. I carefully straightened the wire against a flat board using pliers, but it took a long time and I wasn’t very pleased with the results.
The other day, I stumbled across a different technique that I had never heard of to straighten copper wire. All you need to do is draw the wire, under tension, back and forth repeatedly against a rounded surface. (This only works for solid copper wire, not stranded wire.)
I used a fairly long piece of wood that I propped up vertically like a column. I then looped the length of copper wire around the wood and held the wire very tightly at both ends. I drew the wire repeatedly across the wood, from one end to the other. It only took a few passes, but the kinks and bends disappeared almost like magic. I was left with an a nearly completely straight piece of copper wire.
The one caveat is that this won’t work if the wire is damaged. One piece of my copper wire had a cut that I hadn’t noticed and that piece broke under the tension when I tried to straighten it. That wasn’t a problem because I would have discarded the damaged piece had I seen it.
If you need to straighten some solid copper wire, then you should give this technique a try. This is a tip that I wish I had learned about long ago.