Pianotech

Subject: Keytop repair

1.  Keytop repair

Posted 17 days ago
Greetings,
The piano is a Zimmerman, a GDR (East German) upright, probably from the 1970s-1980s. Almost half of the molded key tops have come unglued (see photos). Although replacing them might be the preferred course of action, I suspect that the cost may be more than the owner is willing to bear. What type of fast acting contact cement or glue would be suitable to reattach the key tops with a minimum (or even no) clamping time?

Thanks,
David

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David Trasoff
Professional Piano Service
Los Angeles, CA
323-255-7783
david@professionalpianoservice.com
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2.  RE: Keytop repair

Posted 17 days ago
CA glue works very well in situations like this.

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Willem "Wim" Blees, RPT
Mililani, HI 96789
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3.  RE: Keytop repair

Posted 17 days ago
Contact cement. 

Gary Bruce
Registered Piano Technician





4.  RE: Keytop repair

Posted 17 days ago
PVC-E glue

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Regards,

Jon Page
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5.  RE: Keytop repair

Posted 17 days ago
To underscore Jon's suggestion, PVC-E will certainly give you more working time than CA will, and that matters in terms of precise placement of the key top on the key stick.

Alan

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Alan Eder, RPT
Herb Alpert School of Music
California Institute of the Arts
Valencia, CA
661.904.6483
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6.  RE: Keytop repair

Posted 17 days ago
Fast? Proper gluing don't work like that. Clean the surfaces, apply the glue, clamp, clean up.
Pvc-e is what I use. I've never seen it fail. But I do see contact cement failures all the time. 
Pvc-e can be finger clamped a minute or so if in a pinch in house. 
In the shop I use a homemade wedge clamp, that also centers the keytop on the key head.
-chris





7.  RE: Keytop repair

Posted 17 days ago
For something like this, I'd use the glue trick. You can find my article about it in the October 1997 Journal.

The basic protocol is to mix CA and white glue. The white glue acts as a mild and non-toxic "kicker" for the CA, which sets up in a few seconds.

If the keytops were ivory, I'd put a thin even smear of white glue on the key stick, then put dots of water-thin CA on the back of the key top, not smearing it around but being sure that there are some near the corners. Gingerly pick it up and turn it over, since any CA on the ivory will need to be removed with acetone. Press down carefully with really clean dry hands to make sure it's the right place, and it should be stuck in a very short time. The reason for using the white glue on the key stick is because water warps ivory. Wipe away the squeeze out, once again being sure none of it gets on top.

For plastic you could probably do it either way -- a thin smear of white glue on the back of the key top, dots of CA glue on the key stick, with attention to the corners, carefully put it in place and press, being especially careful not to let any CA get onto the top, because the acetone in it makes it etch the key top, and you will not get it back off. I think I'd leave that little brown residue from the previous (failed) adhesive. It probably would accept the glue better than bare plastic.

I used to put the dots of CA on the ivory and then quickly spread it out with a small screwdriver to make a thin even sheet of it. I found that it often sets up too quickly this way, and some of the ivories would come back off. The dots give you a few seconds more time, since the CA in the middle of them isn't exposed to atmospheric humidity, so it stays liquid longer.

I've found, looking at old but replaced plastic key tops, that contact cement often seems to warp them a little, leaving them looking lumpy. The CA-white glue never does this. You just have to pay very close attention so none of it ends up on top. Also, from experience, if your hand contacts CA while it has even a trace of white glue on it, it will get stuck to yourself or some other thing with much greater ferocity than usual. I found this out by gluing my left thumb to the middle of my index finger while putting on a rubber button one day. I actually had to go to the car and use nail polish remover to free them. Even then, it took some time and effort.

It's a good idea, using CA, to have some acetone along with you, not that you should need it if you are careful.

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Susan Kline
Philomath, Oregon
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8.  RE: Keytop repair

Posted 17 days ago
Hello, David,

Since I don't see it mentioned elsewhere; and, in a previous lifetime
wound up servicing a number of Zimmerman instruments (I think that it
was Bernie Comsky who was the importer in LA), I'm chiming in long
enough to suggest that, before doing much gluing, that you check the
keys carefully to see how much, if any, measurable/noticeable shrinkage
along the length of the key has occurred over the years.

Note that I'm not necessarily suggesting/insisting on a deeply reductive
analysis here. (Unless you have access to factory manufacturing
specifications, you can't.) Rather, a careful examination and
measurement of several keys per section to see if there is any
noticeable difference in length of the head, tail, overall length,
distance from front to balance, balance to capstan...that kind of thing.
Many lower-end Eastern European instruments from that period had
poorly cured and overly-kilned wood from which questionable keysticks
were cut.

If there isn't a noticeable amount of variation in the sticks, you're
probably OK with any of the suggestions previously made. If, however,
things are looking flaky, key-wise, and the owner doesn't have the money
or doesn't want to spend it, you've got a series of choices/decisions to
make as to how to proceed.

YMMV.

Kind regards.

Horace

On 11/30/2017 11:50 AM, Susan Kline via Piano Technicians Guild wrote:
> Please do not forward this message due to Auto Login.
>
> For something like this, I'd use the glue trick. You can find my article about it in the October 1997 Journal.
>
> The basic protocol is to mix CA and white glue. The white glue acts as a mild and non-toxic "kicker" for the CA, which sets up in a few seconds.
>
> If the keytops were ivory, I'd put a thin even smear of white glue on the key stick, then put dots of water-thin CA on the back of the key top, not smearing it around but being sure that there are some near the corners. Gingerly pick it up and turn it over, since any CA on the ivory will need to be removed with acetone. Press down carefully with really clean dry hands to make sure it's the right place, and it should be stuck in a very short time. The reason for using the white glue on the key stick is because water warps ivory. Wipe away the squeeze out, once again being sure none of it gets on top.
>
> For plastic you could probably do it either way -- a thin smear of white glue on the back of the key top, dots of CA glue on the key stick, with attention to the corners, carefully put it in place and press, being especially careful not to let any CA get onto the top, because the acetone in it makes it etch the key top, and you will not get it back off. I think I'd leave that little brown residue from the previous (failed) adhesive. It probably would accept the glue better than bare plastic.
>
> I used to put the dots of CA on the ivory and then quickly spread it out with a small screwdriver to make a thin even sheet of it. I found that it often sets up too quickly this way, and some of the ivories would come back off. The dots give you a few seconds more time, since the CA in the middle of them isn't exposed to atmospheric humidity, so it stays liquid longer.
>
> I've found, looking at old but replaced plastic key tops, that contact cement often seems to warp them a little, leaving them looking lumpy. The CA-white glue never does this. You just have to pay very close attention so none of it ends up on top. Also, from experience, if your hand contacts CA while it has even a trace of white glue on it, it will get stuck to yourself or some other thing with much greater ferocity than usual. I found this out by gluing my left thumb to the middle of my index finger while putting on a rubber button one day. I actually had to go to the car and use nail polish remover to free them. Even then, it took some time and effort.
>
> It's a good idea, using CA, to have some acetone along with you, not that you should need it if you are careful.
>
> ------------------------------
> Susan Kline
> Philomath, Oregon
> ------------------------------
> -------------------------------------------
> Original Message:
> Sent: 11-30-2017 13:02
> From: David Trasoff
> Subject: Keytop repair
>
> Greetings,
> The piano is a Zimmerman, a GDR (East German) upright, probably from the 1970s-1980s. Almost half of the molded key tops have come unglued (see photos). Although replacing them might be the preferred course of action, I suspect that the cost may be more than the owner is willing to bear. What type of fast acting contact cement or glue would be suitable to reattach the key tops with a minimum (or even no) clamping time?
>
> Thanks,
> David
>
> ------------------------------
> David Trasoff
> Professional Piano Service
> Los Angeles, CA
> 323-255-7783
> david@professionalpianoservice.com <david@professionalpianoservice.com>
> ------------------------------
>
>
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9.  RE: Keytop repair

Posted 17 days ago
Will all due respect, David, I would just bid on how long it would take you to do it right. Keytops aren't something you want to mess up, because they're very noticeable. And, should you use something like contact cement to glue it, if there's a mistake it's permanent. Unless you route out the key top, in which case you've just made several more hours of work while trying to save them money by doing it quickly. Several more hours for which you don't get paid, because it was your mistake.

In situations like this, what I do is to give a range of between 75 and 150% of the time you think it will take to do it the right way, aka not rushing. Then charge for the actual amount of time you spent doing the job. If it took longer than expected, then the clients not shocked. But if it takes less time than expected, then give them a discount and receive a big thank you in return.

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Benjamin Sanchez
Professional Piano Services
(805)315-8050
www.professional-piano-services.com
BenPianoPro@comcast.net
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10.  RE: Keytop repair

Posted 17 days ago

My $0.02:
Contact cement is "quick and dirty".  You might get some slight discoloration if the yellow cement shows through, though not likely.  I find that contact cement has about a 10 or 20 year lifespan; enough to get you far enough down the road that you won't get blamed.  Use fresh glue.

PVE glue is excellent and essentially permanent if the surfaces are clean, it works better if the key top is slightly roughened.  Clamping can be a serious pain as it will shift or "creep" under a clamp.  I use brass weights to hold it down; check alignment frequently.  It can "bite" or set in as little as 10 or 15 minutes, though it takes hours to properly dry; overnight is best.  One brand of PVE glue is Franklin Titebond Melamine Glue.  The glue from Schaff is slightly better.

I have heard many great things about CA glue and many swear by it.  I have had to clean off countless bad CA glue bonds that came off (not mine), mostly because of poor preparation or glue "kicking" before the key top got on.  I can't get it to work myself.  Good luck!

Duco Cement should work well, but I don't have much experience with it.

I just repaired two pair of hiking boots with "Shoe Glue" that was very interesting.  It is a type of hard silicone glue (vinegarish smell) and works well on my boots.  There might be some new and useful glues coming down the pike someday.



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Blaine Hebert
Duarte CA
626-795-5170
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11.  RE: Keytop repair

Posted 17 days ago
I'm in the camp of: Explain that there are 1) "band-aid" (quick and dirty) repairs which may or MAY NOT work well due to whatever it was that caused the failure in the first place (or possibly complicate matters further), and 2) "do it right" repairs that you can stand behind and will last the remainder of the piano' s lifetime.

Of course, door #2 is always more expensive. But, in the end it may be less expensive since if door #1 fails in short order, that only leaves door #2 and now they'll spend twice (not looking good for you) forgetting the fact that they should have done this before...

It's largely in the way you present it. AND, people spend their money WHERE THEY WANT TO. Experience teaches this.

The following sentence can be very effective:  "I wish I could give you a quick and easy way out of this, but unfortunately in this case, there just isn't one".

If you trust them, start offering payment options like stretching it out for three months, etc. This has a psychological effect of making them bite the bullet.

Pwg​​​

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Peter Grey
Stratham NH
603-686-2395
pianodoctor57@gmail.com
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12.  RE: Keytop repair

Posted 17 days ago
I like to use Coleman's extra strong CA glue from Colesman's Tools. It is strong like epoxy but convenient and fast as CA. Works well with ivory. I use PVC-E with plastic keytops. Dries flexible like rubber cement and is extremely tenacious.
Paul McCloud
San Diego




13.  RE: Keytop repair

Posted 17 days ago
I’ve dealt with the same piano with the same situation. I used PVC-E glue , and then add a drop or two of CA medium viscosity (or thick.) Press for a few seconds, move to the next keytop, after pressing the next keytop, go back and press the first one.
PVC-E sets up fairly quickly, and the addition of CA helps accelerate the process because the water content in the PVC-E acts as an accelerant for the CA. 3 years on, no keytops have come unglued again.
You can do this with ivory too, but it requires clamping for a bit because it will curl if not clamped (from water in the PVC-E.)

Joe Wiencek
NYC




14.  RE: Keytop repair

Posted 17 days ago
I would discourage a quick and dirty approach just to get the job done. Do it right or do not do it at all - there is far too much shoddy work that I have had to make right or deal with. You are the expert and the professional and trying to "save" money using band aids or the quick fix backfires . It looks like plastic keys and you may not have success getting all of the old glue residues off. One approach is to send the keys out to get recovered by a key service so shop around for those options. I would avoid using CA due to the quick bond but also the damage it will do to the key sticks if/when key tops need to be re-positioned or replaced. Go with PVCE as others have stated. The curved nature of the keytop material should make positioning easier and pvce gives you some open time. You could use painters tape to hold the keys in place and then use a  boards with clamps on the ends and in the middle to help the bond cure . The DINDIRL approach will always be more expensive in the end.

(DINDIRL - Do it now, do it right later). As professional we have the opportunity and I feel the responsibility to DIRN- Do It Right Now

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James Kelly
Pawleys Island SC
843-325-4357
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15.  RE: Keytop repair

Posted 16 days ago
PVC-E glue can be used in similar fashion to contact cement and works well and permanently for acrylic tops.  Brush it on both surfaces and let them sit for five minutes or so, until they don't feel tacky. Press them together and they'll stick for good.

When replacing keytops I use Melamine glue from Titebond and Oslund key clamps.

For regluing ivory, yellow wood glue on the key stock, thin CA on the top.

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Philip Stewart
609-774-7571
www.njpianoservice.com
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