Okay. For a field replacement of a Yamaha keytop. I must stress field replacement because I DO NOT do this when I replaces a set of key tops. That is a completely different process.
Yamaha keytops are 2 parts, front and top. Most of the time I do not have to replace the front.
You will require:
Heat Gun
Razor Blade or good sharp knife
Contact Cement
1 Large File
1 Small File
1. Check to make sure you have the appropriate key(name) and coloring is matching the best it can. It is a good idea to show the customer a head of time and explain that a 10+ year old key will have changed color and the new one is exactly that, new. In all my cases the key was close enough (or exactly the same) to not offend anyone.
2. Remove the key from the piano
3. Heat the damaged key top, away from the piano, until it peels off the key stick, you may need to use the knife or blade to get it started. Do not chip it away or break it away. The goal is that the heat will soften the plastic so that it peels off leaving a clean wood surface. Make sure to continually to move the heat gun across the keytop so that you don't burn one area of the key stick. If you need to you can lightly sand the key stick if you have glue residue but done right the plastic will just peel off.
4. With the naked key stick, place it back into the piano. Trim the side tabs (carefully to not break it) of the replacement keytop so that you can dry fit the key top with its neighbors in the piano (you may want to remove a sharp if necessary.)
5. Line up the key top's front with it's neighbors so that you get a nice straight line. Make sure to observe the front of the key top to make sure it is not too fat against its neighbors. If this is the case you'll need to lightly file it into a round shape from underneath the keytop. (most people won't notice this, but I will)
6. Once you have it all lined up appropriately and you are happy with the dry fit, mark the keystick at the back of the keytop, so you know how far forward your over hang is going to be.
7. remove the keystick
8. Apply a light amount of weldwood contact cement to the underside of the keytop and to the keystick. You have to do both surfaces or else the glue will fail. The instruction on the glue bottle is actually pretty good. Let it dry to a point where each surface is no tackier than a Post-It note.
9. Place the key back into the piano
10. Line up your keytop and apply it to the surface of the keystick. You'll have a few seconds of working time before things adhere. If you get squeeze out or anything of that sort you used way to much glue. Any hanging glue from the front or sides will clean off very easily since the glue doesn't stick anything that is not itself.
11. remove the keytop
12. File the overhangs on the sides. I usually draw the large file downward from keytop to stick. The plastic will file off. Be careful of the corner where the sharp lives. We will handle that with the key in the piano. Keep working the long sides of the keys and the fat front of the keytop until you have a nice rounded surface and flush with the wood. reinstall the key from time to time to compare with its neighbors.
13. Install the key and remove the sharp(s)
14. Using the smaller file, file the space where the sharp is to match its neighbors. This is most critical step because it also the most noticeable. If you oops, then match the neighbor to your oops, but it has to be clean and straight.
15. stand back and look at your accomplishment and clean up the mess you made.
It took me longer to write this than to do it. Attached at pictures.
I have fixed many Yamaha keytops from snow globes, angry spouses, children, warranty work, and many more things. All of those repaired keys are happily playing along with their neighbors today with no issues what so ever. Again I stress that I do not do this when I replace a set of keytops in the shop. That is a completely different method with clamps, cauls, and PVCe glue and so on and so forth.
It pretty straight forward and once you do one you'll see how easy it is for Yamaha. Other brands of key tops it is a similar process but more work or prep work will need to be done. For instance replacing a Steinway Kluge key can be done, but I prefer to pre-shape the keytop ahead of time with a band saw because the only Kluge keytops I have are currently complete rectangles. Other brands from supply houses, or keytop with attached front may need more filing. When I have a job like this it is all about the appropriate warnings and disclaimers ahead of time.
I hope this helps. I attached pictures from a tutoring session i gave on this topic.
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Gregory Cheng
West Chester PA
267-994-5742
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Original Message:
Sent: 08-18-2019 10:48
From: Alan Eder
Subject: Yamaha M keytop chip
Gregory,
I am interested in your method for replacement of a single keytop, and would wager that I am not the only one. Please share it!
Alan
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Alan Eder, RPT
Herb Alpert School of Music
California Institute of the Arts
Valencia, CA
661.904.6483
Original Message:
Sent: 08-18-2019 10:32
From: Gregory Cheng
Subject: Yamaha M keytop chip
Floyd is correct Yamaha sells key tops by the octave and by the set. I see so many Yamaha that I just went ahead and bought the set. It was cheap enough to not even consider the difference between $6 or $14 or something like that.
In my experience Yamaha has 2 type of key tops, the white plastic and the fake ivory type. Everything below a Model C3 is white plastic, C3 and up is the simulated ivory type. (I don't know what they actually call it).
Replacing the keytops on a yamaha is rather straight forward and I can usually do one keytop in the customers home in about 30 minutes or so. If you are interested in learning my method of a single keytop replacement on a yamaha in the customers home feel free to contact me.
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Gregory Cheng
West Chester PA
267-994-5742
Original Message:
Sent: 08-17-2019 17:46
From: James Kelly
Subject: Yamaha M keytop chip
A client has a Yamaha M that has a small chip on the left front corner of C4. I have the acrylic repair kit but have never used it. I have done many polyester repairs but this would be the first. Before I do it if I do it I would practice on some other plastic keytops. Looking for tips/tricks/suggestions to do the job right or is the better solution to get the repair done by a key service and/or order keytops from Yamaha (assuming they sell them) the piano looks to be in excellent shape from pictures I have seen .
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James Kelly
Pawleys Island SC
843-325-4357
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