Pianotech

  • 1.  The Baldwin SF-10 Break Decision

    Posted 10-03-2022 14:03
    Hi all,
    An unusual situation has occurred. I'm working on a Sf-10. The strings i had ordered f2-c#3(strings 33-50) were not made properly, the string maker got a little over zealous on the swage. As a result, as i was bringing the f2 up to pitch ( for the first time), when i got a whole tone below, the tone of the string would die and start creaking. I called the string maker for replacements, they mentioned this was Baldwins biggest error, that the model F use to have just steel gauges(gauges 19,20,21). Questions: was there a problem to fix with the original scaling? Or should i go back to the original? Or stay with the "bad" Baldwin Modification? If anyone has been confronted with this before, which way did you go?

    Much thanks in advance.

    -chris

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    Chernobieff Piano Restorations
    "Where Tone is Key, and Mammoths are not extinct."
    865-986-7720 (text only please)
    ------------------------------


  • 2.  RE: The Baldwin SF-10 Break Decision

    Posted 10-03-2022 20:02
    Update: I'm past the point of changing the scale, so i am stuck with hoping the new strings will work. But. i made a video of the weird bass string problem.


    ------------------------------
    Chernobieff Piano Restorations
    "Where Tone is Key, and Mammoths are not extinct."
    865-986-7720 (text only please)
    ------------------------------



  • 3.  RE: The Baldwin SF-10 Break Decision

    Registered Piano Technician
    Posted 10-04-2022 01:16
    Wow, That is strange. Be sure to give us an update when you get the replacement bass strings. I'll be mulling this one for a few days. I assume the tone comes back when you lower the pitch back down...

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    Tremaine Parsons RPT
    Georgetown CA
    (530) 333-9299
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  • 4.  RE: The Baldwin SF-10 Break Decision

    Posted 10-08-2022 10:54
    Hi Chris,
    I presume the bridge pins have no give or cracks? Could it be Bridge Roll or bridge losing crown, or bridge delaminating from SB?
    Creaking could be loop sliding down or up on hitch pin if unseated.
    Just stuff to check 
    Richard 





  • 5.  RE: The Baldwin SF-10 Break Decision

    Registered Piano Technician
    Posted 10-04-2022 16:58

    Hmm.
    Chris, you mentioned "over-zealous on the swage", and "creaking".  That dead tone reminds me of a wound string which is contaminated with crud or corrosion; cure (sometimes) is to remove string and roll a running loop of the string down the full length (I'm sure you know the drill).  So this got me thinking of this possible scenario: 

    As string is brought up to pitch, the core wire elongates resulting in slight separation of the winding turns.  This separation is good, as it gives the nice tone (corroded strings rub at each winding turn rapidly attenuating the higher partials).
    But maybe on your strings, as you approach the target pitch, windings covering one of the swaged ends slip, permitting the windings to collapse slightly along the core and rub -- killing the tone.  I know this sounds like a long shot, but I've never heard this particular defect before!
    You might try letting the pitch down (which lets the core "retract" into the windings).  Then pull pitch up just *before* you start losing the tone.  Then try tapping the winding over a swage (could be either end) and see it that kills the tone.

    Good luck!



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    John Rhodes
    Vancouver WA
    (360) 721-0728
    jrhodes@pacifier.com
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  • 6.  RE: The Baldwin SF-10 Break Decision

    Posted 10-04-2022 17:26
    Interesting thoughts so far for sure. Will Truitt called me and he suggested that the swage is so weakened the its reaching the end elasticity.
    Anyways, i just downloaded a zoom app and took this photo. See what you thing. The swage is double the string diameter at this angle and quite flat the other angle.
    -chris


    ------------------------------
    Chernobieff Piano Restorations
    "Where Tone is Key, and Mammoths are not extinct."
    865-986-7720 (text only please)
    ------------------------------



  • 7.  RE: The Baldwin SF-10 Break Decision

    Member
    Posted 10-04-2022 18:32
    I think the string is toast and has been pulled /stretched beyond its limit- look at the space between the windings . Looks like you should get two new strings to stand a chance of getting to the right pitch for the note. Maybe the measurements where off ? Also I thought "swage" refers to the part of the winding that is flattened down to keep the winding from unwinding

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    James Kelly
    Owner- Fur Elise Piano Service
    Pawleys Island SC
    (843) 325-4357
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  • 8.  RE: The Baldwin SF-10 Break Decision

    Registered Piano Technician
    Posted 10-04-2022 20:00
    Well that is strange. Chris, I have read that some string winders put a swage in the middle of the string. I can't see the ends of the windings in your excellent zoom photo. Are they at the end of the winding? Is the core wire standard or a Paullelo type?

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    Tremaine Parsons RPT
    Georgetown CA
    (530) 333-9299
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  • 9.  RE: The Baldwin SF-10 Break Decision

    Registered Piano Technician
    Posted 10-05-2022 09:50
    This is what happens when you advertise on Craigslist for employees. 😉

    Peter Grey Piano Doctor

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    Peter Grey
    Stratham NH
    (603) 686-2395
    pianodoctor57@gmail.com
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