Hammers (long)

[John Hartman]

Dear list,

Any time I here that we should want our hammers to be resilient I become 
perplexed. Resilience is the property of an object to return to it's 
former shape after it has been deformed by a force. If we really want our 
piano hammers to be resilient we shouldn't make then out of felt. Felt is 
pretty far down on the list of resilient materials. Some have said that 
adding hardeners or compressing the felt with heat will make them less 
resilient.  In fact they become more resilient. Another thing that 
bothers me is the demonstration of cutting the hammer from the crown to 
the molding and seeing how far the felt returns to it's pre-pressed 
shape. This resiliency demonstrated by this is of no consequence. What 
matters is how the hammer behaves in contact with the strings. 

A well formed piano hammer will display differing elastic properties 
depending on how forcefully it impacts the strings. Soft playing requires 
low resilience. Loud playing requires high resilience. The entire process 
of bending the felt around the hammer molding is designed to make a 
hammer with a gradient of density from crown to molding. While it is true 
that this process increases the overall resiliency of the hammer, 
creating the gradient, I believe, is more important.

I see nothing wrong or evil in using hardeners such as lacquer on hammers 
(I prefer the term stiffening agents). I realize this is a very unpopular 
view especially considering all the negative reports both on this list 
and at many PTG conventions classes. I feel that many of these opinions 
stem from a lack of information on how to lacquer hammer from the raw 
state. While there has been a lot of good information on how to top 
lacquer hammer provided by the Steinway company these techniques will not 
work to full advantage on a new set of cold-pressed hammers. What is 
needed is an understanding of deep foundation voicing with stiffening 
agents. 

Another reason that hammer lacquering has been condemned is the abuse of 
the technique in the futile attempt to revive a piano with a dead or 
dying soundboard. This approach will result in an ever louder attack at 
the beginning of the note with less tone to follow. Considering that many 
larger rebuilding shops make soundboards will little or no crown many of 
us have experienced the frustration of trying to achieve a round tone 
with enough power in the lower treble and upper tenor areas. No amount of 
stiffing agent will restore the tone. I believe the present popularity of 
heavier hot-pressed hammers is that they work better at correcting the 
above soundboard problems. Heavier hammers will dwell on the string 
longer. This will shift the energy to lower partials. Lower partials tend 
to fill out the tone after the attack. 

I use medium to med. light weight cold-pressed hammers with stiffening 
agents.  My technique yields very consistent results and it is quite 
fast. I spend almost no time needling the hammers or cutting back the top 
layers of felt to get to a harder layer. The stiffening agent do most of 
the work. Another benefit is the long term stability of the voicing. I 
have come back years later and the hammers only need minor needling, 
mostly on the strike point.

John Hartman RPT