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lid hinge pins stuck

  • 1.  lid hinge pins stuck

    Registered Piano Technician
    Posted 11-05-2023 18:30

    Lists,

    We have a Yamaha C7 from which we are currently unable to remove any of the lid hinge pins. We have had the lid off this piano several times over many years. Can't get any of the three pins to budge, even with someone raising and lowering the lid while pliers are on the hinge pin, being struck by a rubber mallet.

    As you might imagine, we are curious about what may have caused this condition. And knowing the cause may steer us in the right direction about how to remedy it.

    But regardless of whether or not we figure out the cause, we have to fix it. What is the best brass to brass lubricant? 

    Also, we have considered trying to drive the pins out with a drift, made of either brass or something softer. Anyone with experience doing this care to weigh in?

    Thanks,

    Alan 



    ------------------------------
    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
    ------------------------------


  • 2.  RE: lid hinge pins stuck

    Registered Piano Technician
    Posted 11-05-2023 19:25
    I strike the pliers with a metal hammer. It hasn't failed to remove a hinge pin yet. 

    A drift (punch) from the other end is an alternative, but it's hard to keep it centered on the end of the pin, and it will only drive the pin a short distance before the geometry (angle versus straight) intervenes. A nail set has a dimple on the end that could help with that, and it might at least get the pin moving.
    Regards,
    http://fredsturm.net
    www.artoftuning.com
    "Education is not preparation for life; education is life itself." John Dewey






  • 3.  RE: lid hinge pins stuck

    Registered Piano Technician
    Posted 11-05-2023 20:17

    Fred,

    Ditto my response to Wim about matriculating to a hammer.

    If a hammer doesn't work, I will try a nail set to get it moving. If at that point it still can't be pulled out, perhaps grind the pointy end of the nail set down so it can reach further into the hinge.

    Alan



    ------------------------------
    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
    ------------------------------

    Original Message


  • 4.  RE: lid hinge pins stuck

    Registered Piano Technician
    Posted 11-05-2023 20:26
    Alan,

    I have a lid removal kit always ready to go. It's in a small contractor's bag with my business card in a window slot.  It has a small needle-nose pliers with the teeth ground smoother, buckskin to use to grab brass pins to prevent gouging, a small hammer to tap against the pliers (or vice grips) as Fred mentioned. It has a piece of cardboard and painters tape to put against the rim in case you're afraid of making gouges, and spare hinge pins. It also has a 1/8" punch to push out ball-end or stubborn pins, and it's always worked well.

    So handy, that most of my venues have requested that I make and sell kits to them.

    Kathy

    Sent from my iPhone



    Original Message


  • 5.  RE: lid hinge pins stuck

    Registered Piano Technician
    Posted 11-05-2023 20:28

    Thanks, Kathy.

    Alan



    ------------------------------
    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
    ------------------------------

    Original Message


  • 6.  RE: lid hinge pins stuck

    Registered Piano Technician
    Posted 11-05-2023 19:25
    Alan

    You're trying to be too gentle. 
    One, any lubricant will work, but I would start with Protek.  Even WB40 will do in this case. 
    Two. Use a hard hammer, hitting the pliers. I would use vice grips on the end of the pin, and whack it with a hammer
    Three. If the second method still doesn't work, use a 2 penny nail, not a brass rod, to drive the pin out. Again, hold on to the nail with vice grips and smack the nail with a hammer. 

    On a side note, the hinges are probably bent, which is the result of movers putting the piano on its side without a skid board. If none of the suggestions above don't work, it will require 3 men to hold the lid up at 90 degrees, while someone unscrews the hinges. 

    Wim 





  • 7.  RE: lid hinge pins stuck

    Registered Piano Technician
    Posted 11-05-2023 20:13

    Wim,

    A rubber mallet has worked for 40 years, but since it isn't working in this case, I guess it's time for more firepower!

    Alan



    ------------------------------
    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
    ------------------------------

    Original Message


  • 8.  RE: lid hinge pins stuck

    Registered Piano Technician
    Posted 11-05-2023 21:16

    I offer this in good humor. Back in high school, our auto shop teacher had the philosophy of "Don't force it. Use a bigger hammer." The theory was that sometimes the need to take something apart that doesn't want to come apart forces you to break it first. (Think expanding action brackets.) Afterwards, you can then easily either repair or replace it. 



    ------------------------------
    Geoff Sykes, RPT
    Los Angeles CA
    ------------------------------



  • 9.  RE: lid hinge pins stuck

    Registered Piano Technician
    Posted 11-06-2023 06:18
    Grab that pin with a vice grips and hit that vice grip with a steel hammer.


    Mike Lynam
    Registered Piano Technician
    207 350 9548




  • 10.  RE: lid hinge pins stuck

    Registered Piano Technician
    Posted 11-07-2023 04:37
    you can turn the pin tail 45 degrees then waggle it out with a stripe. The hinge pin is not rounded and will lock in the hinge hole at normal position. 

    Regards

    KK Cheng
    RPT from HK
    IMG_6972.jpgIMG_6973.jpgIMG_6975.jpg



    Original Message


  • 11.  RE: lid hinge pins stuck

    Registered Piano Technician
    Posted 11-07-2023 10:54
    Something that might help is put the lid up and loosen (NOT remove) the hinge screws.  This might give you the wiggle room it needs.



    Original Message


  • 12.  RE: lid hinge pins stuck

    Registered Piano Technician
    Posted 11-08-2023 11:07

    Mike's suggestion is the right one.  For stage pianos, which have the lid removed regularly, I created a small tool box containing the vise grips, a small hammer, a screwdriver, and extra hinge pins.  It stays nearby.  The reason the pins can't be removed is most likely they are bent from previous removals, and/or the hinges got damaged for the same reason.  It bears mentioning that once the pins are removed, the lid should come off OR there should be a prominent sign saying there are no pins in place.  If the lid is off, the cover should go back on to keep the stage lights off the piano.

    Ken




    Original Message


  • 13.  RE: lid hinge pins stuck

    Registered Piano Technician
    Posted 11-09-2023 10:03
    Hi all
    Usually the hinge pins are bent for a reason; to make the hinge fit or because they were rattling because of a poor fit.  

    Removing and replacing the pins require proper instruction to the people doing the removal. The pins should be matched to the hinge and don't mix from one piano to another.  To do this mark one part of the roll over of the hinge (you only need to color two of them) with a matching color of the pin.  I use nail polish-no one can see this from a distance.  To make it easier for the people doing the work absolutely use 3 people for a concert grand, use the bent pins not the ball pins, use something firm to cover the latch or pin hole at the treble end of case part of the piano to prevent marking the case or breaking a part. A folded up moving blanket, hard cover thick book will work. This allows the wiggle room to match the hinge positions before that treble pin falls into the socket. 

    The pins will not be exactly the same so before marking them make sure that they slide in and out. And make sure that the crew knows how to do this.  If there are two pianos find a few more colors (marker, white out, ?)

    Always make sure the hinge is pinned before you lift a lid.  If the hinge pin is part way out,  the pins are most likely mixed up.  Sometimes one pin will go in with the lid lifted a bit and another without and having the treble lid pin out of the socket makes the wiggling easier.  Replacing a hinge is no easy task! 

    And for Allen E maybe having the lid up a bit at the treble might make the removal easier. 
    Good luck

    Sent from Gmail Mobile



    Original Message