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Etreme tuning pin toque and jumpiness, part II

  • 1.  Etreme tuning pin toque and jumpiness, part II

    Posted 07-02-2018 05:10
    Went back to see the piano with so many tuning pins torquing out above 250 inch-pounds. Was loaded for bear--drill motors, reamers, rosin in powder form and in solution, a small sledge hammer and pin-block support jack, and the like--prepared to administer every possible remedy suggested, on the list and off.

    Step one was to measure and record the torque of each and every pin, eventually settling into a routine of tuning the string as best as possible with the torque wrench (!) after each measurement. Of the torque wrenches I had gathered, by far the best was the one I had acquired from Pianotek (0-250 inch/pounds). It measures in both directions (as opposed to having a ratcheting function), and allowed for surprisingly good control while tuning.

    Then I tried the simplest and fastest potential remedy, Jon Page's "wrench it back and forth 20 or 30 times." I used the tightest pins to experiment, and proceeded in increments of 10 back-and-forth turns at a time. It worked! No need to try other remedies (on this piano, at least), although if I had the time, I would have tried them all, just out of curiosity.

    A string broke, not at the becket, but where the wire turns to go around the pin. In the first two splice attempts, the new wire failed just as it was being brought up to pitch. On the third attempt, it was the original wire that failed. In the mean time, I removed the newish-looking, nickel-plated, 2/0 x 2 3/8" tuning pin. The size of the pin suggested that a new pin block had been installed.

    Took the attached photos while the pin was out. Zoom in on the tuning pin hole. Any idea what we are looking at here (besides a sloppy stringing job, that is)?

    Alan

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    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
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  • 2.  RE: Etreme tuning pin toque and jumpiness, part II

    Posted 07-02-2018 07:51
    without a real closeup, it looks like the face of the block was "glassed"...epoxy. If that is so, and the plate was dropped onto the epoxy covered block face, the epoxy ozzed up into the holes. Not sure that effects the torque much, though.

    Were your rotational moves fast or slow?

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    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
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  • 3.  RE: Etreme tuning pin toque and jumpiness, part II

    Posted 07-02-2018 10:49
    Jim,

    Taking Ed McMorrow's caution about being careful to not glaze the holes in haste, I would turn at a moderate speed, pause, then turn back.

    Alan

    ------------------------------
    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
    ------------------------------



  • 4.  RE: Etreme tuning pin toque and jumpiness, part II

    Posted 07-02-2018 14:07
    Very curious photos, indeed.

    Pwg

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    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
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  • 5.  RE: Etreme tuning pin toque and jumpiness, part II

    Posted 07-03-2018 08:26
    Is this an older piano? Did you look at the bottom of the pinblock? Did it look new or old? It looks like some sort of fiberglass-type material. Jim could be correct about fiberglassing (or epoxy?) the top of the block to fit the plate (sounds a bit crazy to me.....), but even if someone tried to do something like that, why would they use fiberglass cloth (it looks like some cloth material in the picture)?

    I wonder if this is not the original block and someone either swabbed or filled the original holes with some sort of fiberglass/chopped-mat material, let cure and then drilled (or not?). Perhaps that is the reason for the excessive torque.

    Or maybe they swabbed out the hole with fiberglass/chopped-mat material and then tapped the tuning pins in and THEN let it cure. Now THAT might produce some nice torque?!?!?!?!?!  YIKES! I shudder to think.....

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    Terry Farrell
    Farrell Piano Service, Inc.
    Brandon, Florida
    terry@farrellpiano.com
    813-684-3505
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  • 6.  RE: Etreme tuning pin toque and jumpiness, part II

    Posted 07-03-2018 11:06
    Terry,

    Thanks for your input.

    Yes, it IS an older piano, and no, I have not been able to get a look at the bottom of the pin block.

    Someone who responded off-list also conjectured that we are looking at fiberglass cloth that had been inserted in the tuning pin holes. And maybe some kind of adhesive as well.

    When I first encountered this beast, I told the customer that the best solution would be to restring with a new block. He asked that I experiment to see if there is a less expensive way to make this piano tunable. I figured that if someone is happy to pay my hourly for me to learn something new, I am down for that!

    Alan

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    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
    ------------------------------