Piano Hammers are one of the heartbeats of the piano. The ones we have now are a result of centuries of trial and error. They are made with wool, sometimes from a few breeds all around the world mixed together. Unlike string scale and plate design, it is impossible to engineer scientifically what sound will result by any new method, process or wool mixture. It is fascinating to me to trace the history the hammer. Their shape, density, wool mixture and type and more produce different tones. Some of the features of a hammer can change during its life. For example, the head slowly flattens as wool is rubbed away by the string. This results in a poor contact point which dampens the string at the same time it is supposed to excite the string. It’s kind of like riding the breaks in a car as you are trying to accelerate. It also looses its springiness. Believe it or not a hammer bounces like a tennis ball because of the oval and sometimes diamond shape. But as the head is flattened it bounces less and less which allows the head to sit on the string longer, again dampening the string and dulling the tone.
Here is a picture of old and new hammers.
On Right: A new piano hammer.
On Left: An old worn piano hammer.
It is important to keep them the correct shape or tone, dynamics, and repetition will slowly get worse. They can be reshaped a few times by a sanding method but eventually replacement must be done.
Reshaping clears away the grooves that wear in the tip and brings back the good shape needed for good tone. Usually I don’t need to voice the hammers after a good filing. This is something I would consider general maintenance that gives a bang for the buck. It is very affordable. By itself it costs no more than $80.00, sometimes less and I often include it with some of my other services.
Consider bringing back your piano’s round clear tone!