Pianotech

  • 1.  Plate crack

    Registered Piano Technician
    Posted 06-16-2022 11:45

    Greetings fellow technicians

     

    I inspected a 1988 Schimmel yesterday, a 6' 10" grand.  A store is considering buying it or putting it on consignment.  I found a crack in the plate as shown in the photos.  In the first photo the crack is pretty obvious, along the corner of the strut.  In the second photo it's harder to see – it runs along the length of the "molding" and then becomes a hairline crack along the strut in the background of the photo.  This is in the 3rd section.  I cut a little strip out of a business card and was able to insert it 3 mm into where it looked like the crack was deepest, so I would guess that the crack is likely 4-5 mm there.  I also found a prominent buzz in C#, D and D# in the 6th octave, in the same section as the crack.  I hunted for the source of the buzz and it seemed to be somewhere near the strings of these notes; I couldn't find an object on the soundboard or any other source, although it was very hard to inspect with a flashlight and mirror – the plate is close to the soundboard.  The piano is only a bit out of tune.  So here are some questions I'm pondering:

     

    Could such a crack cause the buzz?

    Given the depth and extent of the crack, does it seem that it will take a long time for anything bad to happen?

    Would such a crack get worse with the strain of moving?

    Should the store reject the piano outright?

    If the store rejects it and it turns out to be hard to sell, what should one do with the piano?

     

    Aside from the buzz in those few notes, the piano has a wonderful tone and touch.  I'm guessing it could give years of pleasure to some young pianist who can't afford to buy a used high-end grand that is a sure bet.



  • 2.  RE: Plate crack

    Registered Piano Technician
    Posted 06-17-2022 00:49
    I’ve seen this once before. In my case, the piano had no problem staying at pitch and the crack had absolutely no affect on the overall condition of the piano — it had been there for years prior to my arrival.

    That’s not to say your piano will respond the same way, but if it’s already at pitch and stable, there’s a chance it could be just fine.

    Benjamin Sanchez, RPT
    Piano Technician / Artisan
    (256) 947-9999
    www.professional-piano-services.com




  • 3.  RE: Plate crack

    Registered Piano Technician
    Posted 06-17-2022 02:12
    Considering the piano seems to hold tune pretty well, and after looking at the photo, I'm going to suggest that it's not a plate crack but simply a crack in the paint. The paint on the plate can get pretty thick in places and if/when it cracks it can sometimes look like a crack in the plate. I doubt it's the source of the buzz.

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    Geoff Sykes, RPT
    Los Angeles CA
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  • 4.  RE: Plate crack

    Posted 06-17-2022 04:18
    It would be useful to purchase a feeler gauge and go back to check those cracks again.  Feeler gauges are what mechanics use to gap spark plugs, and go down to .001 or .002".  A business card is much thicker and bends easily.  You will get a truer sense of the depth of the crack with the feeler gauge.  

    It may be that there is both a crack in the paint as well as in the plate itself.

    I would consider the buzzing a strong warning sign that something is rotten in Denmark.

    It is a poor risk for the store, so the problem should remain with the present owner.


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    Will Truitt
    Bristol NH
    1-603-934-4882
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    Original Message


  • 5.  RE: Plate crack

    Posted 06-17-2022 06:59
    Hi Loren,

    I have observed these types of plate cracks in both Bechstein and Schimmel. The plate web (strut) crack is likely the most concerning, but these are clear indications that the plate casting / material composition is disintegrating.

    These could clearly be ticking time-bombs, especially with a move, and certainly during any future plate removal. On the other hand, remarkably, I’ve seen plates like this continue for decades on into the future without any trouble. The buzzing strings are a red flag.

    This would certainly impact future resale. It’s not something I would touch, but it needs more research.

    There was a whole series on the journal covering various levels of plate repairs.

    I’m sure there’s going to be other posts on this by the time I respond, but I would clearly document what you found and the possibilities.

    Ian Graham
    Piano Technician
    Instrument Restoration
    www.igraham.ca




  • 6.  RE: Plate crack

    Posted 06-17-2022 07:32
    Is the molding strip cast integrally as part of the plate, or is it decorative molding added after casting, then heavily primed and painted, in which case the cracks may be due to paint shrinkage? Seeing all the sharp edged, detailed decoration is an indication that there may be considerable post-casting additions to the plate. You might test with a magnet, it may be plastic molding. Perhaps a tiny hole could be drilled to feel if the raised strip is cast iron or some softer material.

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    Ed Sutton
    ed440@me.com
    (980) 254-7413
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