Pianotech

Last summer I replaced the hammers on a Yamaha C7 with Abel hammers. This is in a rehearsal room of a university and the floor is carpeted. To me the piano sounded great, but almost immediately the faculty said the piano was too soft. No power.  A couple of weeks ago I added a generous amount of B72 to the hammers, and the sound came alive. But now the complaint is that while the piano is loud enough, it is also thin and tinny. I need some advice as to how to keep the volume but get rid of the thin and tinny sound. 

Wim

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Willem "Wim" Blees, RPT
St. Augustine, FL 32095
Tnrwim@aol.com
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HI Wim,

Sounds like (ha!) the hammers are missing an essential element which is soft felt at the surface for pianissimo quality which in this case seems to be lacking.  Aggressive sugar coating is needed.  Traditional thin shallow needles won't do it.   Compass point needling at the right pressure is worth a try.  Compass point voicing needle have an inclusive angle of about 13 degrees. Start with a sample note.  Light pressure straight down all over the strike surface.  Listen...   Keep increasing pressure until the sound starts to bloom.  Once your confidant about the right amount go for it across the sections.  Following with a ball peen hammer can help soften and work the fibers into more flexibility at the surface.

Many years ago at one of the national conferences I demonstrated replacing a hammer around C5 with a solid hard rubber hammer of the same strike weight as adjacent notes.  It was a Yamaha grand.  I slid in the action and played the note.  The audience gasped!  So did I!  It sounded better than the felt hammer!   But wait.  When I played forte the tone sat down and said "NO!"    No core hardness...  When I played into the pianissimo range the tone became thin and tinny.  No surface softness.  I stretched a piece of bushing cloth over the top and the Pianissimo tone bloomed without detriment to the MF tone.    The hard rubber

 with no gradient in hardness the tone only sounds best at one dynamic.

Piano hammers need a gradient of density for good tone at all dynamic levels.   Lacquering tends to make the felt hard from surface to deep.  No gradient.  Hammer weight levels have a huge influence. The lighter the hammer weight level the deeper the gradient needs to be.  Light hard surface hammers are the devil. 

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David Stanwood
stanwoodpiano.com
stanwood@tiac.net
508-693-1583
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A couple points. Wrong technique and wrong chemical.  What i call fortissimo voicing should be done from the side and basically avoid the attack area. You have to pull the action and stand it up, so the sides of the hammers are exposed. B-72 is great for brightening the attack area without creating a ping like lacquer does. But its too soft for fortissimo voicing. Besides because of its softness you need to apply way too much , and by the time it becomes effective, it gumms up the felt. I use diluted sandarac (hardest alcohol solvent resin) for fortissimo voicing and very little is required to hear a difference. Once fortissimo is taken care of, the attack usually require a little B-72 only.

I enjoyed our lunch together very much!~ It was nice meeting you!

Take Care,

-chris

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Chernobieff Piano Restorations

Inventor of Inertia Touch Wave (ITW)
Advanced Resonant Compression Engineered Soundboards (ARCHES)

865-986-7720 (text only please)
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