Pianotech

  • 1.  Bridge cap material

    Registered Piano Technician
    Posted 10-10-2024 17:13

    Hello,

    We had a large Mockernut hickory tree suddenly die this year. Since it was right on our property line and near the neighbor's house, we had to get it professionally taken down. The logs (see below) seem to be fairly nice. While I will process a lot of it for firewood, I'm also intrigued at the idea of processing some of the nicest pieces for bridge caps. Mockernut hickory has a janka hardness of more than 1800. Since questions:

    1. Is hickory inferior to maple?
    2. What instructions should I relay to whoever processes the wood into boards (quarter sawn I presume)?
    3. Does hickory have properties that would make notching more difficult (besides it being harder than hard maple)?

     Thank you!



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    Tim Foster RPT
    New Oxford PA
    (470) 231-6074
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  • 2.  RE: Bridge cap material

    Registered Piano Technician
    Posted 10-10-2024 18:03

    Tim,

    Doesn't Chris Chernobieff use hickory for bridge caps? If he does, but does not see your post, you might want to reach out to him about your question.

    Best,

    Alan



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    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
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  • 3.  RE: Bridge cap material

    Posted 10-10-2024 18:24

    I have used Hickory for several pianos until i discovered Osage Orange. But yes it can be used for Bridge caps. 

    First thing you need to do is get it cut into slabs and get it stickered, stacked and covered. And paint the ends. I usually let it  air dry for at least two years. To work Hickory you do need top of the line chisels and know how to sharpen them. But if you can get that far, then the final product of the extra hard cap is worth it. I do believe hickory has a higher tone wood rating than maple. At least it sounded really good to me. I have a video on my channel bouncing the different woods on an anvil to listen to their tone quality. Before you decide to use it for firewood, you can also use it for many other wood products including dowels. Wolfenden considered hickory to be the best wood for hammershanks.

    good luck!

    -chris



    ------------------------------
    Chernobieff Piano Restorations

    Inventor of Inertia Touch Wave (ITW)
    Advanced Resonant Compression Engineered Soundboards (ARCHES)

    865-986-7720 (text only please)
    ------------------------------



  • 4.  RE: Bridge cap material

    Registered Piano Technician
    Posted 10-11-2024 19:54

    Thanks, Chris, I'll give it a try (in two years, that is). I may try it first in the highest register where the harder wood can be a real asset.



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    Tim Foster RPT
    New Oxford PA
    (470) 231-6074
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  • 5.  RE: Bridge cap material

    Registered Piano Technician
    Posted 30 days ago

    Tim, et al,

    During my false beat research (in an upcoming Journal publication), I discovered that there appears to be a minimum hardness factor for good bridge cap material. Using the Shore "D" scale (the range used for wood) the better pianos incorporate hardness ratings from the mid 60 to 70. Low quality pianos will use material as soft as mid 40 to mid 50. When purchasing bridge material, test the hardness with a Shore "D" meter. There're not expensive less than a $100. 



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    Roger Gable RPT
    Gable Piano
    Everett WA
    (425) 252-5000
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  • 6.  RE: Bridge cap material

    Registered Piano Technician
    Posted 30 days ago

    Thanks for sharing that Roger! Do you happen to know when your article is slated to come out? I've been looking forward to it...



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    Nathan Monteleone RPT
    Fort Worth TX
    (817) 675-9494
    nbmont@gmail.com
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  • 7.  RE: Bridge cap material

    Registered Piano Technician
    Posted 30 days ago

    Nathan,

    I don't know. It's in the hands of Scott Cole, Journal Editor.

    Roger



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    Roger Gable RPT
    Gable Piano
    Everett WA
    (425) 252-5000
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  • 8.  RE: Bridge cap material

    Posted 30 days ago

    There is a simpler test. First recognize that maple is the problem. At a Janka hardness of 1400 psi  its borderline acceptable for bridge caps. Within the species is a large range of Janka hardness, and choosing Rock Hard maple was usually a safe bet. But i have gone to enough hardwood stores to know they do not differentiate between hard and soft varieties all the time. The piano supplier that is popular for buying caps from does not pass my test in quality of hardness. I believe Maple was originally chosen because its relatively easy to carve (that also should tell you something). 

    Thats why its a smarter decision to go with a harder species starting with ash and hickory. Boxwood and Osage are excellent choices. There are others as well.

    And my simple test--- just use your fingernail. If you can leave an indentation, then its too soft for bridge caps.

    -chris



    ------------------------------
    Chernobieff Piano Restorations

    Inventor of Inertia Touch Wave (ITW)
    Advanced Resonant Compression Engineered Soundboards (ARCHES)

    865-986-7720 (text only please)
    ------------------------------