I'll tell you how I'd approach it, and then leave it to you to figure out what procedure to choose.
I'd leave the original glue on the key stick. I'm assuming it's even and there are no lumps. By not sanding, etc., you'll assure that the keystick is flat, uniform, and not slanted.
I'd take a small amount of white glue (like Elmer's) and smear it over the keystick, spreading it out so a thin but uniform layer covers it all.
Then I'd VERY CAREFULLY clean every trace of white glue from my hands.
I'd turn the plastic keytop over onto a clean towel.
I'd drop a number of drops of CA over the keystick, making sure that a drop or two is near both the front and the rear end, but not putting any too near the edges. What is desired is to have some CA every half inch or so along the keytop, but not have so much that any squeezes out. The reason for this is that the main danger from gluing the keytop with CA is that if any at all gets onto the top side, it will be visible and not removable.
Then I'd carefully pick up the keytop by the edges, turn it over, and carefully place it exactly where it should be. There is only one try for this. It is important to keep CA off your hands as you pick up and turn over the keytop.
When you are satisfied with the placement, once again make sure that no CA is on your hands, and gently press the keytop against the keystick, starting in the center and working toward the front and the back. Be sure that if there is any squeeze out that you don't touch it, so it won't end up on top. It can be cleaned off the edges once all the glue has set up.
Sounds more complicated than it is .... but it calls for a very neat-handed approach. Assuming the layer of white glue is even, thin, and wet, and the right amount of CA is used, adhesion ought to be good. You might be able to feel heat through the keytop as the two glues come into contact.
I don't spread out the droplets of CA because leaving them alone means that they will not set up before meeting the white glue. If they are spread into a layer, the humidity in the air will very quickly cause them to set up.
If you have any doubts, given that the piano is in showroom condition, find a scrap key, some kind of plastic keytop or piece of keytop, and practice a little. Because the two glues in contact set up immediately, you do not need a jig or a clamping system. But because CA glue on a keytop (or on a counter top, don't ask me how I know!) cannot be removed or disguised, careful concentration is required.
If you are really fumble-fingered and manage to glue yourself to yourself or something else, having acetone (nail polish remover, for instance) available is prudent -- but you'd have to be really all over the place to need it. Acetone will also trash the surface of a keytop, dissolving it.
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Susan Kline
Philomath, Oregon
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Original Message:
Sent: 09-30-2019 17:28
From: Terrence Farrell
Subject: Re-glueing Keytop
I have an eight-year-old Yamaha upright in my shop that I was doing some keywork on (balancing keys). Upon removing one of the naturals, the keytop popped off. It came off quite cleanly with 99% of the glue remaining on the wooden keystick. I have never installed new keytops on a set of keys (or even one key!). I've done field repairs on old uprights with CA glue, but this piano is showroom condition and I want to do it right (or have it done right). Is there any good technique that I (i.e. one without any keytop jigs/tools) can employ to re-glue this keytop? Picture attached. Or should I just take it to someone who knows what the heck they are doing?
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Terry Farrell
Farrell Piano Service, Inc.
Brandon, Florida
terry@farrellpiano.com
813-684-3505
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