I was introduced to the concept of repairing bass strings only 5 years ago.  A fellow tech friend of mine showed me this simple knot in order to ‘save’ a bass string.  Now before i get down the path too far, some of you might be thinking…’well why not just throw it out and replace with a new string?’  First of all, it it’s plain wire, you do.  Plain treble wire is readily available and there’s no magic in the wire.  When it comes to the bass strings however, they are custom made for the size, model and scale of each piano.  The core wire, the copper winding, the length of the copper and the speaking length all come into play.  You don’t just pick up the phone and ask for a new one… especially when the company has been out of business for 60 years.  In addition, a new bass string will not carry the same ‘weathered’ sound as a the more brilliant brand new string.  Aged strings tend to be duller.  So there’s a lot to be said for splicing a bass string.  This knot (shown in a diagram and also picture) tightens up wonderfully.  There are a few criteria however…

1. The break cannot be in the speaking length.  That’s the part where the string sings.  A knot will inhibit vibration.

2. You must have enough steel to make the knot.  Most recently i went to a home where there was a broken bass string and although i was hoping to splice, the broken wire only had about 1/8″ or about 5mm before the copper… not enough to work with

I usually use brand new wire of the same core thickness at the tuning pin because if it has broken once, it’s probably brittle enough to break again.  Once tight, the string usually acts as normal and you can once again listen to the bass with a continuous flow or sound rather than one note ‘jumping’ out at you.