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John,
Canton flannel buffs are available from: Woodcraft 1-800-225-1153, =
Tool Crib 1-800-635-5140, Rockler 1-800-279-4441, Eagle America =
1-800-872-2511, The Garrett Wade Tool Co. 1-800-221-2942 and many =
hardware stores. Be sure not to get a sewn wheel, get a loose sewn (1 or =
2 stitches) and a loose section (1 stitch at the arbor) Spiral sewn and =
sisal buffs are much to aggressive for keys but good for rough cutting =
metals. When ordering compound, get a buffing compound not a cutting =
compound, and I've found that the closer the color to the object your =
buffing the better. If your interested in knowing, I use 1hp Baldor =
buffing machines @1750 rpm with 10 inch dia. wheels. Separate machines =
for plastic, ivory, ebony and metals. Rake your wheels occasionally to =
keep them clean.
----- Original Message -----=20
From: John Ross=20
To: Pianotech=20
Sent: Sunday, March 06, 2005 1:16 PM
Subject: Re: buffing keytops
Thank you Michael.
Where are those Canton flannel buffers available from?
John M. Ross
Windsor, Nova Scotia, Canada
jrpiano@win.eastlink.ca
----- Original Message -----=20
From: MICHAEL MORVAN=20
To: Pianotech=20
Sent: Sunday, March 06, 2005 1:50 PM
Subject: buffing keytops
John,
I have found buffing to be more of an art than a science. When =
your buffing ivory and bone you are doing two things, one is smoothing =
the surface and removing fine scratches, the other is sealing the pores. =
When your buffing plastic you are smoothing and removing fine scratches =
and not necessarily sealing it because plastic is not porous. I have =
found that a sewn canton flannel buff followed by an loose canton =
flannel buff works well for me. Take into consideration that when you =
are buffing you are simply putting the icing on the cake. What do I =
mean? Buffing is to shine and seal (in the case of ivory and bone.) The =
surface preparation should already be done. Buffing removes fine =
scratches well, and will leave a perfectly flat surface. If one relies =
on buffing to remove deep pits and scratches, this is where problems =
arise. The surface will not be perfectly flat, and heat will be =
generated. Heat will crack and burn ivory and bone, heat will melt and =
deform plastic. The trick is surface preparation, keep the key moving, =
and apply the proper pressure. Compound or rouge plays a role also. =
Compound can contain abrasives, you want to be sure that you are using a =
buffing compound and not a cutting compound. A cutting compound will =
leave as many scratches and lines in the top as you are trying to =
remove. I look at buffing keys as I look at refinishing a piano case. =
Your surface preparation and repairs must be done first, spraying =
lacquer on a piano sanded and left in 80 grit will not be as smooth and =
look as good as a case sanded to 600 grit, grain-filled and sprayed.
----- Original Message -----=20
From: John Ross=20
To: Pianotech=20
Sent: Sunday, March 06, 2005 12:06 PM
Subject: Re: Moulded Keytops, problems buffing
Hi,
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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