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Ivories - Keep or replace?

  • 1.  Ivories - Keep or replace?

    Posted 07-13-2018 07:23

    Greetings all

     

    I just brought home keys from a 1952 Knabe console to replace the keytops.  A dozen or so ivory heads in the middle of the keyboard have come loose, and the customer saved them.  A gentle tug on the ivories that are still attached did not pull them free.  The exposed white cloth is in good shape and firmly in place – just frayed a bit in some places.  The tails are all attached still.  Replacing the key tops with plastic was the plan, but the customer wants to keep the ivories if possible.  Some of the ivories are a bit discolored but none are chipped or cracked.

     

    I was thinking of carefully applying thin CA glue to the edges of the intact ivory heads.  For the detached heads, I would like to try removing the white cloth (I assume this would be better than trying to keep it but not sure) and re-apply cloth or use a coating of some sort.  The customer understands that the color won't be uniform if I go this route. 

     

    Does anyone have experience with this to share?



  • 2.  RE: Ivories - Keep or replace?

    Posted 07-13-2018 08:20
    Mix white titanium dioxide with cold hide glue and paint it on a cleaned keytop. Let dry. Then apply the glue/paint to the ivory and clamp on.
    -chris





  • 3.  RE: Ivories - Keep or replace?

    Posted 07-14-2018 07:55
    and keep the cloth---yes?

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    Cindy Strehlow
    Urbana, IL
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  • 4.  RE: Ivories - Keep or replace?

    Posted 08-10-2018 11:34
    Chris ~

    I tried your method using cold hide glue and titanium dioxide.  I ended up thinning it with water some.  It worked like a charm.  Thank you for the idea.

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    Loren Kelley
    Tacoma WA
    253-376-4545
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  • 5.  RE: Ivories - Keep or replace?

    Posted 07-14-2018 16:40
    Yes, I just did this. I left the wafers in place. The glue was some thicker stuff. It was from the satellite co,, hot stuff. Easily 1/3 the white top fronts were off. I had to separate them into notes then match to the key. The only way to not see the line between the tail and front is to use the original wafers. The ivory is translucent and any glue that gets in the joint shows

    Use just enough glue in the center.
    the thin glue doesn't work well. The medium thick does. http://www.caglue.com/CA-Glue_c_10.html 
    The UFO is thicker than the thin but is still great for tuning pins.

    I used the brass key top clamps like they have at Schaff

    I ran the thin stuff around the edges. If it was already loose, it bulges up the tail and you can see a gap. then you squirt in some the medium thick stuff and  quick clamp.

    sounds brutal but don't worry about it.

    Take a rubber sanding block with 220 and break the glaze and block the sides to remove glue and clean dirt 
    Change to 320 grit and and flatten the the top so the front top matches the tail. If the ivories are worn down the center, avoid flattening the whole top to that thickness.
    You can get the grits at an automotive store.
    Start with 400. all you are doing is taking out the scratch marks from the previous paper. Every 200
    600, 800, 1000, 1200, 1400, 1600.
    Hand rub from 800 up.
    The heat from sanding and buffing will cause any tails to arch. Glue and clamp and re sand.
    Final is to use a white rouge bar and a buffing wheel on the bench grinder. I charged them 900 and it looked beautiful. That was gluing back on all the sharps too. That was interesting to sort those out. From the ones that were still on,, it was the wear pattern from playing that did the final guess when I had a choice.

    The piano is in an antique house and the tops are still on solid after climate changes. 
    It was a real pretty job





  • 6.  RE: Ivories - Keep or replace?

    Posted 07-14-2018 08:27
    Schaff sells the glue wafers, cails and clamps. Procedure is as follows:
    1. Clean key to wood. Water and steam will release the old glue wafer. Clean the ends of the ivory and remove any old glue by scraping. 
    2. Heat the brass cauls by setting a hot iron on them.
    3. Fit a new wafer to the key by laying the wafer on the key with the wafer touching the intact piece of ivory. Bend the extra length over the front of the key to mark it, then cut off the excess wafer with scissors. Don't worry about the sides yet.
    4. Dip the wafer in water for a short period of time just to start to get it wet.
    5. Place the wafer on key. Pick up the hot caul with pliers and set it on the ivory. Place the clamp on the caul and tighten enough to keep the ivory flat and level with the existing ivory. Tightening too much will crush the key and cause the repair piece to be lower then the original. The ivory will want to shift sideways as the clamp is tightened, so have a small knife or other tool to push it back in place as you apply pressure. When doing only fronts, clamp a tail caul on so that the tail doesn't come off or break as you repair the head.
    6. Let everything cool then remove the cauls and file the extra wafer off the side of the key.

    To do a field repair, clean any dirt off the top of the key and the bottom of the ivory by scraping. Spread a very thin coating of wood glue on the key. Place a very small drop of CA glue near the corners and one in the center of the ivory. Place the edge of the ivory against the existing ivory for alignment and drop the ivory on the key. Check for alignment and gently rub for good contact. 

    Hope this helps. 

    Rex





  • 7.  RE: Ivories - Keep or replace?

    Posted 07-14-2018 09:14
    Loren

    Thought of two things after sending the last reply.
    First, when you set the wafer on the key, line up one edge with the edge of the key and check the ivory from that side to see if it is in the correct position. 
    Second,  the cauls for the key fronts have a ridge on them so you can clamp them with the clamp pulling the head back against the tail for a tight fit. 
    Also,  check to be sure that the head does not ride up over the tail.
    Don't worry if something doesn't go on correctly the first time. Steam and heat will pop the mistake off and you can try again with a new glue wafer.
    Rex