Pianotech

  • 1.  A sorry reminder never to touch areas of replaced and mismatched bass strings.

    Posted 18 days ago
    At the weekend I was tuning for a very much looked-forward-to concert. The instrument was nice, to say the least, and whilst tuning unequal temperament nothing I do should cause any problem with an instrument. It was a Bosendorfer Imperial. Having come across a very helpful discussion about tuning to 444 or 443 in which someone had most helpfully included the scaling graph
    http://18019014610044144640.googlegroups.com/attach/abe43c57796888e3/bosendorfer.jpg?part=0.1
    what presented to me as replaced and odd strings on 1, 2, 8, and 9 if not others looking in detail, should have been warning to me not to touch any in the region. I simply should not have touched them.

    What a surprise it was that number 6 was to be next, and I was to be the one with the short straw who copped it. :-)

    In the morning I tuned - it was at 440.5 and for safety and standardisation I took it down to 440. All was well. The concert showcasing the relevance of tuning, I returned in the afternoon and with a rise in temperature the pitch had fallen to 439.5 and, exactitude of tuning being rather paramount for this concert, I went through and tweaked some notes. Having had no problems in the morning and gone down in pitch the loss of string 6 was a surprise.

    At least I survived strings 14 to 18 at higher tensions although the strings were giving me an uncomfortable feeling on the lever and I was guarded in my movements as a result. Bicords at least don't cause loss of a playable note . . .

    I use a very accurate machine, unknown in the USA, the CTS5, very deliberately to give exact standardisation to what I do from tuning to tuning, and to minimise unnecessary movement of strings. I'd tested the bottom two strings traditionally aurally finding the 3rd harmonic node at arms length down the string, checking the perfect 12th and checking that the nodal note matched what my machine was telling me listening to the 3rd harmonic. This meant that as I went up I was exercising maximum care and not moving unnecessarily. However, with the mismatched strings tonality was changing going from old to new to old requiring an aural best match of harmonics and this might have caused either me or previous tuners to hunt slightly in this region for the best match and progression giving more metal fatigue on the entry to the coil.

    No doubt all of us look back at things we might have done and where better judgement would have told us to stay away. I shouldn't have touched those strings.

    On the other hand, on a concert piano, it's rather a surprise and a disappointment that others curating this instrument had allowed it to continue with mismatched strings visibly and audibly different putting on what might be expedient to install in a hurry rather than installing a new set.

    String 0 appeared to be thinner than string 1 and without measuring I wouldn't like to testify to the absence of other gauge irregularities.

    Very vexing, and to the instrument's owner I've had to eat humble pie and take whatever remediation might be deemed appropriate on the nose. As the instrument was to be tuned the next day for another concert by its regular tuner, simply sending off the string perhaps to Gregor Heller and fitting a new one in the weeks necessary wasn't an option. Luckily bottom Bb isn't a note which most concerts require.

    Best wishes

    David P

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    David Pinnegar BSc ARCS
    Hammerwood Park, East Grinstead, Sussex, UK
    +44 1342 850594
    "High Definition" Tuning
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  • 2.  RE: A sorry reminder never to touch areas of replaced and mismatched bass strings.

    Registered Piano Technician
    Posted 18 days ago
    David, if I understand you right, it seems that lowering the pitch was unnecessary as it dropped .5 cents on its own in the course of the day. It's worth considering the daily ebb and flow of room temp if you have a target for when the piano is going to be used.

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    Steven Rosenthal RPT
    Honolulu HI
    (808) 521-7129
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  • 3.  RE: A sorry reminder never to touch areas of replaced and mismatched bass strings.

    Member
    Posted 18 days ago
    Obviously there where problems in the entire bottom. String 0 is thinner than the next one. Isnt this piano a model with an extra octave at the bass end and probably difficult to tune to begin with ?  Anyway we inherit what went before us. I tuned a Baldwin L last week for a concert and note 88 did not sound , 86 had a broken string at the tuning pin anf F6 played erratically. In addition I had to glue on 13 plastic keytops that where missing totally. Upon closer examination note 88 had been restrung with a thin universal bass string. F6 was a cheating jack because the jack spring on the rep lever/whippen had barely any tension . Fortunately I had a box of plastic keytops and fast drying glue. I should have mentioned that the top lid hinge pin was missing. I sacrificed a thin shafted screwdriver. New bass strings need to be treated with caution. Who knows if they have been overpulled, never slowly stretched or are even the right size.

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    James Kelly
    Owner- Fur Elise Piano Service
    Pawleys Island SC
    (843) 325-4357
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  • 4.  RE: A sorry reminder never to touch areas of replaced and mismatched bass strings.

    Registered Piano Technician
    Posted 18 days ago
    David,
    Even though you may have been fighting against poor previous technical decisions, I would certainly recommend lubricating the bearing points with something fancy, non-petroleum base. Prolube is what I use to limit string breakage, and many on this list recommend Jon Page’s CBL (which I have not tried, but likely will soon enough.) Though excess friction may not have been your tuning nemesis here, it eliminates one variable that can mask other delicate “tuning” issues. Even on newer pianos.

    Splicing bass strings is a highly useful skill, and can have nearly 100% success rate, particularly if the string breaks at the tuning pin. It won’t solve string scaling problems, but it will get you through a concert and much beyond if the client will not spring for new strings.

    Joe Wiencek
    NYC




  • 5.  RE: A sorry reminder never to touch areas of replaced and mismatched bass strings.

    Posted 18 days ago
    Thanks to all.

    Yes - I agree in principle that there's an argument about lowering from 440.5 to 440. With unequal temperament though one's measuring just one of the twelve pitches and tweaking others, some probably up and some probably down so being safe and avoiding raised tensions would seem a good idea. 

    The previous week I'd had a nasty wakeup to this with my own Bechstein which having been tuned in the summer at 440 now, like the instruments in France I met a couple of weeks ago, had gone up to 442. In the interests of stability I kept the Bechstein at 442. As when it had come to me nearly 40 years ago it was at 444 I considered this fine. Again just before a concert, bottom Ab went on me. 

    So in one case I played safe and went down by 0.5Hz and in the other I kept it as it was, and copped it on both.

    As for splicing, as the Bechstein was my own instrument, and I needed a "get out of jail free" I tried a splice. This however was over the bearing felt and I did the splice knowing the consequences. First time it slipped whilst second time metal fatigue in the old string gave way just a semitone below pitch. https://www.youtube.com/watch?v=2h_VXV0vSmA was the concert which perhaps people might enjoy as the audience did. I placed a strip of red insulation tape on the top of the black out of action key.

    I hope that in discussing failure here it might help others less experienced to avoid the same mistakes in the future.

    Best wishes

    David P

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    David Pinnegar, B.Sc., A.R.C.S.
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    +44 1342 850594





  • 6.  RE: A sorry reminder never to touch areas of replaced and mismatched bass strings.

    Member
    Posted 18 days ago
    It is a good idea to strip the windings off old or broken bass strings and have a supply of core wires in your stringing kit. Ask me how I know. I have had the experience of trying to do a bass string splice only to have the knot slip out or the string break elsewhere. Its better to have a new piece of core wire to make a coil with and be spllced to the speaking length. Its also a good idea to practice string splicing since there are a number of knots that can be used and you never know when a string will go.
    Remember the saying Technicians do not break strings. Strings break.

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    James Kelly
    Owner- Fur Elise Piano Service
    Pawleys Island SC
    (843) 325-4357
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  • 7.  RE: A sorry reminder never to touch areas of replaced and mismatched bass strings.

    Posted 17 days ago
    Thanks James and Joe

    I'm sure that comments in this thread will be to the help and encouragement of those in the future.

    When I come across an instrument with friction at the agraffes or da capo bar, I often apply 3in1 machine oil which I believe to be well behaved and to my knowledge and understanding doesn't do naughty things. In using it for a decade I haven't discovered any anyway. What is the theory?

    Putting the splice within the speaking length . . . often there's not much free uncovered wire between copper covering and the agraffe . . . the knot takes some space so I can envisage the knot coming up to the agraffe before pitch is reached and then, with old strings as with the knot I tried on my Bechstein, metal fatigue on the old wire on the tight bend of the knot took its toll and it broke again at the knot anyway. Am I envisaging this correctly?

    By the way, I looked up the serial number of the Bosendorfer - it was 35541 from around 1982 so original strings in concert use with frequent tunings . . . time for new ones after 40 years' service.

    Before tuning an instrument new to me, if I've got mobile phone with me, the graph that Pianometer makes (even though I don't use it to tune) can be very revealing -
    This was a quick scan of the keyboard and the outlying notes are not the instrument but moving too fast from one to another or someone or something making a noise at the relevant near pitch. The bottom A of course actually shows flat as its the extra notes not shown below the bottom of the standard 88 note range.

    After in unequal temperament

    Again, due to limited time and tecchies moving around for the day's activity this graph was a quick zip through and not necessarily giving each note to settle with the software, so not definitive.

    It looks as though I'd let down the bottom Bb which broke and which had been sharp of the Equal Temperament Railsback curve before. I'm intrigued by many instruments I come across where the top octave is absurdly sharp, off the scale here in the as-I-found it graph. When I bring those notes down I hear them come into resonance. Tuned apparently conventionally they're so sharp they're not resonating with anything and lose both power and musical effect.

    Looking at the graph were it to have been C2 which had broken, being pulled sharper, I'd have forgiven it rather than the bottom Bb which went flatter and actually where it should have been.

    Best wishes

    David P






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    David Pinnegar BSc ARCS
    Hammerwood Park, East Grinstead, Sussex, UK
    +44 1342 850594
    "High Definition" Tuning
    ------------------------------