Moulded Keytops, problems buffing

[John Ross]

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Thanks, Hubert.
I have tried some that are cloth circles/washers sewn together, but they =
seem too aggressive. I was wondering about the availability of ones with =
different materials.
I feel I will have to go the mail order route, but I need an address.
I will be driving to MARC, from the east coast, what are the names of =
some stores I could try?
I will be passing Bangor, Portland, down the corridor to Hartford, then =
west, but north of New York City.

John M. Ross
Windsor, Nova Scotia, Canada
jrpiano@win.eastlink.ca
  ----- Original Message -----=20
  From: hubert liverman=20
  To: Pianotech=20
  Sent: Sunday, March 06, 2005 1:57 PM
  Subject: Re: Moulded Keytops, problems buffing



    Hi,John

    I have a motor out of a clothes washer that rotates at 1760 rpm. I =
put a chuck on the shaft and it works for misc small jobs. Yard sale =
season is at hand and you should be able to pick one up to try at very =
little expense.

    HubertLiverman
    Tuner/tech
    Opelika,Al

    Joe had mentioned problems buffing.
    I also have problems in this area.
    I had thought on a softer buffing wheel, but have been unable to =
find a source. The selections available at my suppliers, are limited.=20
    Any ideas?
    I had thought on slowing the wheel down. Would that help?
    John M. Ross
    jrpiano@win.eastlink.ca=20
      From: MICHAEL MORVAN=20
      To: Pianotech=20
      Sent: Sunday, March 06, 2005 11:50 AM
      Subject: Re: Moulded Keytops


      Joe,
          I agree with you 100%, thank you, it is wonderful that you =
know these things and are willing to share them. Molded keytops are all =
the same dimension within one set. Keysticks unfortunately are not =
(except for several sets of Yamaha keys I've covered that were within =
0.004 of each other). I've found that most sets of keys differ in =
length, width and height. I have one set of keys I'm recovering now =
where the keysticks vary in width up to 0.065. This makes recovering =
them tricky. If you have a keystick wider than the top you will have to =
trim the stick, if the top is wider you will have to trim the top. =
Molded tops being the same width have the contours and radiuses "molded" =
into them, so if you trim this you will, as you said then have to =
reshape them, the radiuses and contour to match and yes, the dreaded =
buffing. I prefer to apply what I call custom tops. This is  similar to =
factory procedures in which you apply a separate top and front. If done =
this way one can trim the excess and shape the keys regardless of the =
inconsistencies in width and yield good visual results. I've found that =
buffing plastic and ivory both have there areas of concern, but I use =
different wheels and techniques for both with good results. On the topic =
of keytop materials, I'm pretty sure I have all of the material =
available within the states and offer them. I have also acquired =
material from Aug. Laukhuff and Otto Heuss from Germany as well as P&S =
organ supply from England. These materials are of very high quality and =
texture but expense prevents their wide use. I've noticed that piano =
manufacturers are trending towards thicker and thicker tops, this means =
replacement tops will need to be thicker. I actually have a stash of =
keytop material that is 0.105 thick, but very rarely use them. I am not =
adverse to machining down the keystick to accommodate a new top because =
I am doing it on milling machines with tolerances to within a few =
thousandths of an inch, and it must be done. If one measures a keystick =
at 0.970 and is putting on a top that is 0.075 than you machine the key =
to 0.895 and you have retained the original dimension. The original =
dimension must be maintained or there will be a regulation nightmare. In =
some cases I find that a keystick has been machined with little regard =
for tolerances, and then a corrective measure must be applied. Three =
choices exist, have a new keyboard made, use a thicker or thinner top =
(depending on which direction the error is made), or build up the keys. =
Two of these choices are very expensive. Keytop replacement is tricky =
and is a decision that should be well thought out. The keyboard is a =
major focal point of the piano, it is the interaction point with the =
piano and is the foundation of all regulation. It is a challenge to =
balance appearance, playability and economy. Joe, what do you mean by =
"stink in my shop?" are you referring to a particular glue or the smell =
of machining off old plastic and ivory?  Mike
        ----- Original Message -----=20
        From: Joe Garrett=20
        To: pianotech=20
        Sent: Sunday, March 06, 2005 1:03 AM
        Subject: Re: Moulded Keytops


        Michael Morvan said: "The quality of the keytop, quality of the =
=3D
        piano, quality of the rebuild, preference of the customer, =
knowledge and =3D
        preference of the technician and budget. Crappy "molded" keytops =
are =3D
        nice if applied properly, and three thousand dollars worth of =
new ivory =3D
        is "crappy" if not applied properly. Molded keytops have the =
advantage =3D
        of being inexpensive, uniform in shape and appearance, and =
relatively =3D
        easy to apply with minimal skill, tooling and yields fair =
results.  A =3D
        disadvantage is that many people feel that they are a cheap top =
and as a =3D
        result do not use them."
        Michael,
        What you've said, I agree with. However, it's what you didn't =
say about moulded keytops that concerns me.
        1. Moulded keytops assumes that all key sets are the same =
dimension, which they are not. Therefore, trimming is necessary. Here =
lies the rub, as trimming of moulded keytop material is far more =
difficult than other materials. Especially in making the key set look =
consistant and have a smooth feel under the players hands. Secondly, if =
you've ever had to (try) to buff out scratches of moulded key top =
material, (and I'm sure you have, if you do keytops for a living.), it's =
next to impossible, as the material is too soft and will "burn/gaul" =
when even light pressure on a buffing wheel is applied. I'm not saying =
it can't be done, but it's a royal pain in the patoot to do!<G> Lastly, =
my aversion to moulded keytops is that it is too thick, especially for =
many older pianos with tight tolerances of the piano furniture. This =
requires milling the keystick down. I am totally averse to this practice =
for many reasons. Some of the "moulded keytop material" from Europe is =
better as some of it is what we call "Plexiglass". This material can be =
sanded and buffed. It's still too thick for my eye.<G> I too do keytops, =
but as only part of my overall service to my clients. I used to have =
someone else do it, as I really don't like the stink in my shop. Out of =
frustration with others I've taken to doing it....stink or not.<G>
        Regards,
        Joe Garrett, R.P.T.
        Captain, Tool Police
        Squares R I=

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