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Key bushing glue?

  • 1.  Key bushing glue?

    Registered Piano Technician
    Posted 12-07-2022 16:50
    What key rebushing glue do you use, and why do you like it?

    And what do you think about Aleen's tacky glue for this?

    I'm slightly dissatisfied with hot and cold hide glue for this but I don't want to use something with other problems.
    I also have Roo-Glue melamine adhesive from Pianotek.
    Hide glue tends to create a hard edge in the mortise below the bushing felt and its difficult to apply enough glue for adhesion, and little enough to consistently prevent this glue ledge. Which can click against key pins.
    What I like about hide glue is that it partly sizes the bushings under compression when I'm leaving my brass cauls in for 12 hours.
    I am experimenting with different glues, their adhesion, soak-through, and ability to be removed. Getting ready to rebush another set of keys in a few days...
    Roo glue has similar adhesion, soak through, and seems to soften and loosen for removal with the application of different softeners. It dries to a rubbery consistency unlike hide glue.
    Thanks

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    Tom Wright, RPT
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  • 2.  RE: Key bushing glue?

    Registered Piano Technician
    Posted 12-07-2022 22:39
    If your hot hide glue is making a ridge it is too thick and there is too much of it in the mortise.  I have been using it for many decades without problems, and it is the easiest to remove when it is time to rebush,(university pianos need that).  
    Regards, 



    Original Message


  • 3.  RE: Key bushing glue?

    Registered Piano Technician
    Posted 12-07-2022 23:15
    Thanks Ed!
    Do you retard your hot hide glue at all, or use use it without salt or urea?
    Also, how do you like to remove bushings best? The traditional Dif wallpaper removal or steaming?
    kind regards,
    Tom


    Original Message


  • 4.  RE: Key bushing glue?

    Registered Piano Technician
    Posted 12-08-2022 08:37
    Tom writes: 
    "Do you retard your hot hide glue at all, or use use it without salt or urea?
    Also, how do you like to remove bushings best? The traditional Dif wallpaper removal or steaming?"

      I don't add anything to the glue, and I use a "Hold-Heat" glue pot that keeps it at a temp that has worked all these years.  

       The thickness will determine how far into the cloth the glue soaks, as it determines the thickness of the layer you leave on the wood.  I use the glue at a rather thin mixture for keybushings, as I want the maximum life out of them and if there is 30% of their thickness full of glue, their working life is that much shorter.  Steinway thickness is supposed to be .050", so .020" of that given to a glue seam is too much. My mix is somewhere between whole milk and light cream, applied with a very small brush. Whereas Bill Garlick urged speed in doing this, I find that if the glue is given a little time to cool, it doesn't infiltrate the cloth so much, so I don't rush to install the caul.   
           I like to make sure the shoulders of the front rail mortise are well supplied with glue, and since that area is not a bearing surface, I will usually put a full drop of glue on each of  them and then spread it down the 'wall' of the mortise.  

        A caveat; the heat-setting white glue used by Pratt-Read and maybe Baldwins of the '60's will not let hide glue adhere to it well enough to last.  They seem fine, but begin popping off in short order.  I remove bushings with a steamer I made,(pictures included),  and when the bushings are hot enough, it removes the glue with the felt.  I will still roughen those mortices that don't seem to be free enough from it.  

       I now size my bushings with VS Pro-felt.  I use a thickness of cloth that gives a snug but not 'hard" compression on the caul that is the same size as the pin.  After the glue has dried overnight, I pull the caul, put two drops or so on each bushing, and reinsert.  After a day, the cauls drop out and the bushings are usually a perfect fit on the pins.  I once used hot cauls and it took the glue away from the joint, and I had a bunch of loose bushings falling out.... I use them cold, now.  

    Also, checking the thickness of the balance rail sole plate is essential, and this is part of any action work I do when the keys come off the frame!  4mm is the maximum, and there is a special tool that is worth its weight in gold for getting a good feel to a key job. 
    Regards, 



    Original Message


  • 5.  RE: Key bushing glue?

    Registered Piano Technician
    Posted 12-08-2022 09:48
    Hi Edward,
    Thanks for the tips and the reminder to use the mortise depth reamer at the balance rail hole!

    What about dealing with swollen mortises and key-buttons after bushing removal? Spurlock recommends using a sizing caul while the key is still wet. I have never done this and fear key splittage. But I’m not against trying it.

    I seem to have this problem of tight mortises that tempt me to use a thinner felt. Which I refuse to do out of a desire for quality. I’ve resorted to re-dimensioning each mortise carefully via specific thickness sanding paddles. My mortises look fresh and brand new before I rebush, but it’s a time consuming process.. Any thoughts?
    Use sizing cauls via Spurlock?
    Or, compress the mortises back to original dimensions with the high quality parallel easing pliers?
    Thanks so much for your input.
    I’m looking forward to improving this process that I don’t do that many times per year typically.
    Best,
    Tom


    Original Message


  • 6.  RE: Key bushing glue?

    Registered Piano Technician
    Posted 12-08-2022 10:14

    What about dealing with swollen mortises and key-buttons after bushing removal? Spurlock recommends using a sizing caul while the key is still wet. I have never done this and fear key splittage. But I'm not against trying it.


     hmm,  this is a new one on me.  I haven't noticed mortises being too small after bushing removal, and my drawer of bushing cloth has thicknesses in a range of .045" - .060" which has covered all my bases over the years.  Is the reduced dimension still there after the keys have totally dried?  If so, I would go for the compression approach, as removing material from the key is usually a bad idea, (unless it is the sole plate, where excess material is found as often as not). 
    Regards, 



    Original Message


  • 7.  RE: Key bushing glue?

    Registered Piano Technician
    Posted 12-08-2022 11:11
    Thanks Edward and Ben,
    I’ll use your input and go over my process, see if I can reduce the mortise swelling.


    Original Message


  • 8.  RE: Key bushing glue?

    Member
    Posted 12-08-2022 06:35
    Exactly what Ed said. There is no glue as stable and reversible as hot hide glue.

    Deb



    Original Message


  • 9.  RE: Key bushing glue?

    Registered Piano Technician
    Posted 12-07-2022 23:45
      |   view attached
    Thomas,

    I have also been using hide glue for a long time and have found, as Ed stated, that problems come in two ways,  thickness of your glue mix and how you apply.   I have attached the Spurlock instructions.  While you will have to learn the hide glue mix viscosity differences based on how well you can tell the difference between heavy cream and regular milk, per Spurlock, once you get it right your hardened glue edge will disappear.  Also, I have found Spurlocks suggestion of using the popcyle stick as a glue applicator helpful.  It does take a couple sets to get it consistent but next generation of piano technicians who try to remove your bushing will praise your name.  That is not to say it is the only glue possible, but it is time tested and proven.  Read the Spurlock article and see if it helps.  You do not have to use the Spurlock cauls as the glue application process if pretty much the same for all methods.  

    Also, I never use additives for this use of hide glue. 

    One more thing, regarding the Spurlock process, do not skip the mortise glue priming step.  When you do it you can use a thinner layer of glue on the cloth as the thin glue will strengthen the cloth to mortise bonding.

    Ken

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    Kenneth Jeffs, RPT
    Chesterfield, MO
    kenneth@curtisreso.com
    (314) 960-6389
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    Attachment(s)

    pdf
    spurlock bushing instructions.pdf   1.30 MB 1 version
    Original Message


  • 10.  RE: Key bushing glue?

    Registered Piano Technician
    Posted 12-08-2022 02:54
    I've been using Aleene's Tacky Glue for many years and have found no problem.  It acts just like PVC-E.  I squirt a trail of adhesive the diameter of a wooden pencil lead on the strip of bushing cloth.  Spread it out with an artist's palette knife and use a bushmaster with Spurlock cauls to insert it into the mortise.  I rebush both rails in about 3 hours.  If needed, the bushing removes easily with steam and leaves no residue.  It's inexpensive and all craft stores and Walmart carries it.

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    Mike Kurta, RPT
    N. Michigan chapter
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    Original Message


  • 11.  RE: Key bushing glue?

    Registered Piano Technician
    Posted 12-08-2022 20:27
    Hot hide for me. 47 years and counting. I do add a little urea for retardation. Just enough to make my Bushmaster process efficient. I have to remind myself to dump the glue afterward so I don't "forget" that it is retarded (i.e. altered). Made that mistake a couple of times over the years. No more though.

    Peter Grey Piano Doctor

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    Peter Grey
    Stratham NH
    (603) 686-2395
    pianodoctor57@gmail.com
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    Original Message


  • 12.  RE: Key bushing glue?

    Registered Piano Technician
    Posted 12-09-2022 08:51

    "I squirt a trail of adhesive the diameter of a wooden pencil lead on the strip of bushing cloth.  Spread it out with an artist's palette knife and use a bushmaster with Spurlock cauls to insert it into the mortise. " 


    Seems to me this method would smear glue all over the keystick?

    David

    David Weiss Piano Service
    davidweisspiano@gmail.com
    434-823-9733
    www.davidweisspiano.com



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    David Weiss RPT
    Charlottesville VA
    (434) 823-9733
    davidweisspiano@gmail.com
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    Original Message


  • 13.  RE: Key bushing glue?

    Registered Piano Technician
    Posted 12-09-2022 12:21
    I know some comments have been made regarding processes and possible issues with adhesive application.   One always has to remember many of these process presentations are provided by those whoes success has come with countless hours of experience.  For many, the beginning was filled with frustrating issues of too much glue, too thin or thick mixings, sloppy applications, etc.  As with all we do, be it tuning or repairs, experience is necessary for professional results.  Even with that, we all have bad days when we feel our work in substandard.  

    This post has presented a number of possible glues.  All, with proper application, will hold the bushing cloth in the mortise.  If you new are to the process or looking to "up your game", what has been shared is priceless.  If you are new to rebushing keys, try what you think will work best for you and then practice on some old mortises until you get a feel for the process.  If you are an experienced tech and want to improve your work.  I hate say it, but practice what you think will improve your work before you publically present it. 

    Personally, after 40 years in the business, I am attempting some changes in my processes.   I have done a lot of practice over the last few months and finally feel ready to make it part of my client appointment procedures.  I plan to keep assessing my work and never stop learning.    

    Merry Holidays and Happy rebushing everyone,

    KJ

    PS Posting here always makes me nervous.  There are so many who know more than I do.  :)

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    Kenneth Jeffs, RPT
    Chesterfield, MO
    kenneth@curtisreso.com
    (314) 960-6389
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    Original Message


  • 14.  RE: Key bushing glue?

    Registered Piano Technician
    Posted 12-08-2022 21:33
    Cold hide glue for decades now. It's basically hide glue with urea. It's the right consistency. It holds fine for bushings. The trick is learning how much is too much or too little. That doesn't change with the type of glue you use. If you get squeeze out from the bushing in the mortise you're using too much. Focus on that. Glue that is easily removable is important here. That argues for hide glue hot or cold.

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    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
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    Original Message


  • 15.  RE: Key bushing glue?

    Registered Piano Technician
    Posted 12-09-2022 09:55
    I've used Elmer's School Glue for years without any problems. It's water soluble and will adhere to the residue of the old heat activated glue you find on a lot of mid 20th century keyboards. I remove the old bushings with cheap vodka with a little wallpaper stripper added. I apply it to the bushings with a hypo oiler and get almost no wood swelling if I'm careful not to over saturate the cloth. I apply it with the keys in Surlock clamps and usually the bushings will start to fall out after 2 or three applications  15 to 30 minutes apart.
      When I called Elmer's they told me that Elmer's School Glue is the same as Elmer's Glue All just with more water added to make cleanup easier.

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    Karl Roeder
    Pompano Beach FL
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    Original Message


  • 16.  RE: Key bushing glue?

    Registered Piano Technician
    Posted 12-09-2022 15:08
    Hi Kenneth,
    Here is my process:  Measure the key pins,  clamp the keys, apply a mixture of cider vinegar, wall paper paste remover diluted with water using a hypo oiler, steam out bushings with a damp cloth and a hot iron. If this is an old action with ivories, use an electric bushing sizing caul(warm) and take them out one at a time. Insert the appropriate sizing caul and let it dry at least 4 hours, the longer the better.  Choose bushing material by the feel of the final caul pulling out of the mortice. Test this on several mortices. The caul should have a definite drag when you pull on it, that feel comes with experience. I use hot hyde glue about the consistency of milk or cream, heated in a small glass jar in a water bath using a glue pot to heat the water. Once the glue melts, swab the mortice with a pipe cleaner dipped in the glue. I even water the glue down by dipping the pipe cleaner in the water bath then the glue.  Then go back through and glue up the bushings. I use the Spurlock method. Insert sizing cauls and let dry.
    Apply VPro, reinsert sizing cauls and let dry. There are usually a few that have to be fit or a dot of glue that needs to be "chipped" off the bottom of the bushing.

    A couple things about hyde glue. In colder weather the glue will get thick when spread on the cloth. Work a little faster with less glue spread on the cloth. If the glue gets thick, just mix in a little of the hot water from the bath until you get a better consistency.  Hyde glue does not sqeek and is easy to reverse.

    The hole pin hole in the bottom of the key can be sized by inserting a key pin. Removing the bushings can close up the hole.  In sets that have pulling keys, I turn the keys upside down and steam the hole then insert the appropriate key pin. I have a set of .147 and .160 just for this. It usually sizes the keys. Sometimes the is a little easing to be done or attention must be paid to keys that are still pulling.

    I've done a lot of key bushing work, eventually you come up with a system that just works.  The first sets I re-did to get them right, another reason to use hot hyde glue.
    Hope that was helpful,
    Stewart


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    Stewart Freedman, RPT
    Freedman Piano Service
    Akron, OH
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    Original Message


  • 17.  RE: Key bushing glue?

    Posted 12-11-2022 00:35
    Titebond original handsdown is great for key bushings. It removes easily with heat, and non of that gummie stuff like pvc-e. I tried Titebond Original after watching a youtube video about using it for veneering. Put Titebond on piece to be veneered and veneer, let dry. Iron on. Easiest way to veneer. 

    -chris

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    Chernobieff Piano Restorations
    "Where Tone is Key, and Mammoths are not extinct."
    865-986-7720 (text only please)
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