Sources of "falseness"

[Farrell]

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Does anyone have favorite methods to fix crushed bridge capping?



Recap with quarter-sawn epoxy-laminated hard maple capping material.

Terry Farrell
www.farrellpiano.com
http://farrellpiano.com/bridge.htm


----- Original Message -----=20

>I have a Steinway D in my client inventory that I've just finished a=20
> third tuning service+ on.  It was some fourty cents low when I first=20
> encountered it.  The client wants this piano to be kept in premium=20
> condition from now on for his performance venue.
>=20
> No note was more than three cents (A4) out when I measured it this=20
> time so it is settling down, somewhat.  I decided to do a little=20
> maintenance on the piano/string voicing side.  This involved=20
> tightening loops at the hitch-pins, straightening the path from the=20
> hitch-pin to the bridge pin (surprising how many clicked over into=20
> place), seating from front to back on the rear duplex, light seating=20
> at the back of the bridge, seating via use of a beat-suppressor on=20
> the front side (no tapping).  The pitch dropped, as expected, from=20
> three to sixteen cents.  I then did an over-pull=20
> pitch-correction.  This is followed by seating the wire at the front=20
> duplex, then lifting in front of the capo and then on the back-side=20
> of the capo.
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> After this I fine tuned the instrument.  String noise was greatly=20
> reduced but still persisted in the mid treble on some strings.  I=20
> tried holding something heavy against the front and back bridge pins=20
> and the beating/noise was reduced but not eliminated.  I tried=20
> driving the bridge pins a little.  There was some improvement.  (BTW,=20
> why does Steinway have to grind those pins flat?  It makes it hard to=20
> drive them without risking putting more torque off the driving axis=20
> stressing the hole.)
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> So, I want to list all possible culprits for future investigation.
> Previous over aggressive string-seating.  (some areas look like the=20
> string was crushed down into the bridge)
> Loose bridge pins
> Kink in wire at front bridge pin pulled into speaking length (should=20
> stretch out between tuning intervals?)
> Poorly shaped or too-soft & cut-up capo d'astro bar
> Scaling interference noise (choice of speaking length, node etc.)
> Sympathetic beats from undamped duplexes elsewhere in the piano
> Mis-shaped hammers
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> Did I miss anything?  How do you distinguish between the various=20
> sources?  What are your favorite solutions?
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> Does anyone have favorite methods to fix crushed bridge capping?  I=20
> used CA on bridge pins that had cracks on either side of them on a DH=20
> Baldwin.  I think it kind of worked to fill in some surfaces under=20
> the strings too.  Did this about a year ago, still going fine, and =
going...?
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> How about loose bridge pins?  Is it preferable to go up a size?  Or=20
> is it better to inject epoxy and re-insert?  I've used ultra thin CA=20
> glue on an older DH Baldwin grand that had grain parallel to the=20
> bridge pin torque and there were cracks on either side.  It worked=20
> fairly well.  I'm monitoring for long term results.
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> Kink in the wire?  I stretched everything with a beat suppressor.  I=20
> can't think of anything but time here.
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> Capo problems?  Excess paint and filler here can make noise.  Filing=20
> that off helps.  Poor shape, grooving, a dremel with a long stone=20
> bit works fairly well.  More ideas, cautions?
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> Scaling problems?  Hammer shape/position might help.  Pitch-Lock=20
> clamps may reduce the noise.
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> Sympathetic beats in the duplexes?  Long "bean-bags" such as Spurlock=20
> uses for damper work might help to eliminate this while tuning.  I'm=20
> guessing the Steinway duplexes don't slide around to permit tuning.
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> Poorly mated hammers?  Check and re-shape.  Joe's hammer shaping tool=20
> is cool!  I used it on a Wurlitzer studio piano that needed=20
> help.  It was fast reshaping the hammers and fast to mate them to=20
> the strings.  Amazing what that did to the sound.
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> Other ideas, observations, cautions etc. WELCOME ;-)
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> Andrew Anderson
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> _______________________________________________
> pianotech list info: https://www.moypiano.com/resources/#archives
>
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