Pianotech

  • 1.  Gold plated strings - metallurgy and scaling

    Posted 23 days ago
    Today I had the task of breathing life into an 1880s Pleyel instrument. 
    In due course I'm going to be running issues past the restorer who last saw this instrument a decade ago but bearing in mind changes in the last decade perhaps others here might have helpful experience.
    Knowing French instruments I was expecting either oblong pins or small square pins . . . and expected trouble on that front as my French size lever I keep in France. Upon arrival . . . yes it was small square pins - much smaller than a standard tuning lever can cope with. Luckily my Fletcher & Newman oblong lever from years ago fitted . . .  
    However, that wasn't the main surprise - the strings are gold plated. Knowing the quality of the restoration I was expecting "authentic" metallurgy and scaling . . . so this was a task for "approach with caution". I consulted the restorer yesterday who advised A at 436. I found the pitch at 426 so a pitch raise was in order so I set A at 437 and was considering raising by quadrants over all octaves. On its way up, half way, the first string broke at the coil.
    image
    Bearing in mind the quality of the instrument and rarity of the stringing I went no further and settled to keep it substantially at its original pitch, but taking it down to around 423 to account for a sharpened C and F in unequal temperament.
    Is anyone familiar with gold plated strings? Is the metallurgy likely to have changed as a result of plating? Breaking at the coil and on an instrument which hasn't been tuned since restoration in some years suggests a crystalisation issue, rather as broze harpsichord strings.
    At the 423 pitch the instrument tuned brilliantly and excitingly, and really responding to the unequal temperament. For fun I measured inharmonicity which was extraordinarily low, and the top treble rang out very beautifully putting Duplex Scale instruments into the shade. 
    One would have expected the restored instrument to take the standard French pitch without issue. Five strings were fresher than others and out of tune so clearly the instrument has experienced such a problem before. 
    Apart from talking more with the original restorer my plan of action on pitch will be to analyse lengths and gauges and work out the scaling and resulting tensions . . . but has anyone had any experiences of such a nature and particularly if with such plated strings?
    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: Gold plated strings - metallurgy and scaling

    Registered Piano Technician
    Posted 22 days ago

    Are you sure they were gold plated and not bronze?



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    Blaine Hebert RPT
    Duarte CA
    (626) 390-0512
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  • 3.  RE: Gold plated strings - metallurgy and scaling

    Posted 22 days ago
    Hi Blaine! 

    Yes - real gold plated. The instrument was actually ordered from Pleyel with gold plated strings specified! 

    Luckily I've known the conservator who worked on the instrument a decade ago and he confirms that electroplating does indeed alter the metallurgy and make such strings more brittle. With luck he might have a spare length of the right gauge . . . Apparently the instrument was found at A427 and this might be a reflection of the brittleness of such strings and or the scaling. Measurements will be in order on the next visit.

    Best wishes

    David P




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    David Pinnegar, B.Sc., A.R.C.S.
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    +44 7868385643





  • 4.  RE: Gold plated strings - metallurgy and scaling

    Registered Piano Technician
    Posted 20 days ago

    What is the wire type/maker underneath the golden hood?

    Peter Grey Piano Doctor 



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    Peter Grey
    Stratham NH
    (603) 686-2395
    pianodoctor57@gmail.com
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  • 5.  RE: Gold plated strings - metallurgy and scaling

    Posted 20 days ago
    Dear Peter

    Thanks

    That's the trouble - I don't know and have come to a brick wall in finding out

    Often restorers are close to their chest with knowledge they consider to be proprietary . . . . and bizarrely in the conservation reports there wasn't a set of string measurements done together with tension analysis . . . The restorer deflected my question about what strings were sent to be plated by telling me that the French would not have imported German Roslau strings! I'm in a tiny bit of a tight spot with him as I thought I was going to tune an 1881 Pleyel for a musical friend of a musical friend, only to get to the venue to find that I was tuning a hot potato. Years ago the restorer had told me in passing that he'd restored an instrument there, and I should have known and had forgotten . . . . so sees me as having trod on his toes with his baby . . . 

    However for whoever can take advantage of the situation there's a clear need for any instrument in Pennsylvania Avenue to be restrung with golden strings . . . :-) or alternatively get a special deal on https://www.middlefordpiano.com/www/xiangqinghtml/HGM-231EC_en.html! I haven't enquired of that company whether their instruments come with gold strings . . . .

    Best wishes

    David P




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    David Pinnegar, B.Sc., A.R.C.S.
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    +44 7868385643





  • 6.  RE: Gold plated strings - metallurgy and scaling

    Registered Piano Technician
    Posted 18 days ago

    The only piano that I know of with gold strings here was the Schomacker pianos made in Philadelphia, PA. I've seen two of them with original strings which lasted well over 100 years.



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    Tim Foster RPT
    New Oxford PA
    (470) 231-6074
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