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Jerry is very interested in pianos. He taught himself to play by ear over the years. Make no mistake - he's no virtuoso. But plays well enough to entertain himself and visiting friends if they've had enough wine. Jerry enjoys playing hits from the '40s through '80s, traditional Italian songs, and even some country.
In addition to playing piano, Jerry enjoys tuning, refurbishing, and rebuilding them. He is an active member of the Research Triangle Park chapter of the Piano Technicians Guild. He has twice made presentations to the Piano Technician's guild. One was on touch-weight, described below. And the other was on something called 'partials'. These are the set of frequencies each string produces - something like harmonics. Both of these presentations are attached at the bottom of the page for your review. Some of what's presented will not be completely clear as they are intended to be accompanied by someone (that would be Jerry) explaining it all in front of the crowd. A summary of the touchwieght work that Jerry did on his then-105 year old grand piano is given below.
Touchweight Improvement
Jerry's piano was originally built in 1902. Jerry bought it in 1991. It had been cosmetically refinished, but was in poor mechanical shape. One of the problems was in its 'touch-weight'. Touch-weight refers to the force, typically measured in grams, required to depress a key down, how much force the key pushes back on your finger on its way back up, and two other terms referred to as friction and balance. The DownWard force is abbreviated DW, and the UpWard force is abbreviated UW. Generally a good target DW is 50-55 gm in the base, and 45-50 gm in the treble. UW should start at about 20-25 gr in the base and increase to 25-30 gr in the treble.
In order for the piano to be played with sensitivity, the changes in DW and UW should occur smoothly from base to treble. In Jerry's 100+ year old piano, it wasn't. Most pianos, even when new, have less than desirable touch-weight. In order for touch-weight to be as it should, time consuming customized tweaks need to be made to each key. It is simply too expensive to do this optimizing work on all but the most expensive pianos in the world.
Keys are numbered from 1 to 88, 1 being the most bass key, and 88 being the most treble. The red and blue lines in the first chart below, labeled 'Before Work Started 9/1/07' showed the DW and UP from each key, from 1 to 88. It can be seen that the lines are very erratic going from bass to treble. In a fine piano, they should be fairly smooth.
Jerry set out to fix this. He studied papers by David Stanwood and other renowned piano craftsmen on touch-weight refinement. Jerry replaced the hammers, hammer shanks, fixed friction problems, re-weighted the keys, and did a million other things to improve the mechanical aspects of the keys. The second chart labeled '3rd Try After Front Weighting 2/2/08' below shows the end result of Jerry's work. The DW and UW lines are much, much smoother than when he started. The key friction also decreased smoothly from 14 gr in the bass, to 9 gr in the treble, a very desired result. And the balance weight 'BW' stayed fairly consistent at about 39 grams, another desirable result.
Jerry detailed his work on the Piano Tuners-Technicians Forum of Piano World, http://www.pianoworld.com. Two of the responses he received from very established piano technicians were as follows:
Jurgen Goering of PianoForte Supply
"That is very impressive for a first time go. Congratulations, Jerry. I think you have gone further with this piano than many techs go in thirty years."
G. Fiore Tuner-Technician serving the central NJ, S.E. PA area.
"Good job. It looks better than the readings I get from two high end US manufacturers."
The whole discussion can be seen at
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