Pianotech

I use the center pin flush cutting pliers.  They are not hardened to cut piano wire, but will cut the copper easily. I turn the wire as I'm cutting in the same direction as the winding so it doesn't unravel.  The swaged ends are usually about an inch long, so I will remove about 3/4".  My clippers are the kind that look like regular wire cutters, not the end nippers, but I'm sure they would work too.

Hi Mary,

If you cut off the copper windings, you'll change the tone that the string produces. Once you put it back into the piano, the unison it creates will make a very weird sound and won't ever produce the same clean tone again. It will always sound out of tune no matter what you do. Additionally, if you have to remove the copper windings, the string has broken in such a way that it's unlikely you'll be able to splice it in the first place. 

I'd strongly recommend you order a replacement bass string instead of trying to mess with this one. It will be a much better result and a significantly easier process for you. 

Hi Ben:

This is not my experience.  I tune a C3 at a venue where they regularly break strings.  I have spliced dozens of strings by removing some of the winding in the speaking length and tying a new piece of string.  They sound fine, and don't go out of tune as fast as a replacement.  If you remove too much, then the winding will become loose.  Then it won't sound good and you'll have to replace it.  YMMV.

The copper is softer than the steel. Wire cutters can easily cut it with minimal pressure, and you just hold back to not cut the steel wire. HOWEVER, it can more easily buzz after it has been peeled back. Gently, very gently, use pliers to compress the cooper while gently adding a twist in the direction of the winding. If you push too hard, you'll know it because it will flatten, and you can peel off a wee bit more to try again. If you have ever done electrical work, cutting it is similar to stripping electrical wire, but in this case, the cutters will cause a break in the copper that can be the point the unwinding ends. I hope that makes sense. Maybe I should make a video. LOL 

I didn't see the replies when I replied. You got some good advice! 

Mary,

If we're talking about Bb1 (in the bichord section) and it broke at the agraffe, that's an indicator that the piano has fatigue problems and you can expect more strings to break. This type usually breaks under heavy impact. 

Hopefully when you get there you'll find that it broke at the tuning pin and youll have wire to work with to splice. If not...you've got what you need to do a SL splice. Watch for a splice tail such that it does not touch the other wire. 

If though we're talking about Bb0 in actuality, that's a miserable place to make a splice and will require all the skill you have to make it work. Kudos to you if you're successful! 

Peter Grey Piano Doctor