keytop trimming

Kendall Ross Bean kenbean at pacbell.net
Wed Oct 29 18:55:17 MST 2008


Shawn~
 
What? You're having to file those Pianotek keytops? Send 'em back and get
some that fit!  ;-)
 
Ah, the problem we all struggle with - how to do common repetitive jobs
without mortgaging the farm for expensive tooling.
 
Keytops can be a nightmare. A Dremel might work, if you have a lot of
patience and a lot of money to keep buying replacement bits. Otherwise, it's
too small, too underpowered, the small bits heat up too much, and it takes
way too long, and the money you might have saved is quickly consumed in
having to buy lots of those itty bitty bits in order to get through all 52
white keys. Also, you will still have to devise a fence or a fixture to use
the dremel, and construct it.  
 
A hand file would probably still be faster, if you have the technique, and
the elbow grease to use it.
 
(You might as well get a router and router table and make a router jig.)
 
HOWEVER, you can also use a bandsaw with a fine toothed blade and a sliding
table (see below) (What? You don't have a band saw? Oh, the things we take
for granted...) Often it's faster to cut off excess with a router bit or saw
blade rather than filing, which, as you have found, is tedious. (see below
about router jigs and bandsaws).
 
The main problem with trying to file keytops flush with the wood keystick,
and get a good result, cosmetically and otherwise, is that the wood
underneath the keytops is softwood, and actually wears faster than the ivory
or plastic tops. The sides of the keystick are exposed, so they do get worn
over time, and they also shrink over the years, so that they are no longer
square or straight, so unless you have a fairly young set of keys, filing
new keytops flush with the sides of the keystick usually results in the
keytop being narrower than original, and also results in wider, unsightly
gaps between the keys, giving the appearance that the keys need orthodontal
work.
 
That said, the top should be flush with the wood keystick. If there is any
overhang, it will feel funny to the pianist and they will complain (or
decide not to buy the piano, or pay you for the recovering job).
 
The best hand tools to invest in to do keytops are a good mill file and a
good padded vise (or a regular vise with cardboard or leather taped to the
jaws, or those magnetic jaw rubber pads you can buy in woodworking supply
catalogs). Lock the key in the vise and file away. Go easy at first, it's
all too easy to remove too much keytop, and you can't put it back.
 
A good technique is to keep putting the key back in the keyframe next to its
neighbor at intervals while filing, to check whether you are removing too
much material. It is very easy to get down flush with the key side and keep
filing because it is not always easy to tell when you are flush or when you
have gone too far. Putting the key back in the keyframe with the other keys
shows you the final result, which you can't see when the individual key is
out being filed, away from all the other keys. After you have done a few
keys this way, you will have a better feel for how much filing is needed and
will only have to check occasionally. The other thing that is difficult is
to file the keytop straight, so that the sides are parallel with those of
the neighboring keys.
 
You may find that filing the keytop to where it should be leaves an
overhang, where the keytop is still wider than the keystick. Sometimes in
order to maintain those nice straight narrow spaces between the keys, you
may actually have to build the sides of the keystick back up with sugar pine
or spruce shims, or some type of wood filler, because the keysticks have
gotten really worn. Often, if you look at the key from the front, you will
see that the keyfront is no longer square, but narrower at the top, a
trapezoid rather than a square. Previous recovering jobs may also have
trimmed or filed down the key sides.
 
The main problem with filing is that if you have a lot of material to
remove, you get tired, and lose tend to lose patience, and keep hogging off
material when you should be watching how close you're getting.
 
Bill Spurlock at Spurlock Specialty Tools <http://www.spurlocktools.com/>
has designed some handy router table and drill press jigs for recovering
keys and trimming new keytops, that he can provide you plans for, for a
nominal fee. He claims that with these jigs you can do a complete set of
keytops, including removal of old tops, in 3 1/2 hours. (Perhaps Bill can do
this, but for me that's still a bit optimistic.) I have built the fixtures
and they do work fairly well (watch your fingers, though). The main
advantage of having machines is that you don't get so tired and can do a
better job; also, if used properly, the machines can provide more precision.
The weakness of this, and other router jigs is that they reference off the
key side, so you have to have some skill and technique and know where the
jig cannot be trusted. If the side of the keystick isn't straight, or if it
has recesses for lead weights that the router bit guide bearing can
inadvertantly dip into, good-bye straight sides. In such a case you have to
find ways to compensate for the weaknesses of the fixture. These fixtures
are good for hogging off excess material and cutting down the amount of hand
filing you have to do, but you still have to do quite a bit of finish filing
by hand. Techs who are adept at filing often simply choose to do it all by
hand rather than having to futz with fixture set-up and adjustment, which
eats up time.
 
If you have a band saw that is finely aligned, with a fairly fine toothed
blade (say 14 tpi or more) you can make a sliding table for the bandsaw to
hog off the excess that would otherwise take you a long time to do by hand
if you don't happen to have the stamina of John Henry. The sliding table
keeps the tops of the keys from getting scratched and helps cut a straight
line, and also helps support the keytop so it doesn't chip. This works well
for both ivory and and plastic. If you find the keytop is chipping, either
you need a finer blade or your bandsaw needs aligning. This is especially
helpful for cutting off excess in the sharp notches. (See photos below) Like
I say, even doing this, you still have to count on doing some clean up
filing. Don't have a bandsaw? Find a friend who does. He can probably also
make you a sliding table, if he doesn't already have one. You may have to
buy the fine toothed blade, but that's a small price to pay. Go slow, and
take your time. Don't rush.
 

 

 
The bright side of all this is that if you learn how to do keytops well, you
often can do a better or more meticulous job than the supply houses or
dedicated keytop recovering shops, that is, if you take the time to do a
good job.
 
Hope this helps.
 
~Ken Bean
 
PianoFinders
www.pianofinders.com <http://www.pianofinders.com/> 
e-mail: kenbean at pianofinders.com
 
Connecting Pianos and People

  _____  

From: David's Email [mailto:ilvey at sbcglobal.net] 
Sent: Wednesday, October 29, 2008 10:36 AM
To: Pianotech
Subject: keytop trimming


Archives...
 
List,
 
can anyone give me an idea for the most accurate and least costly way of
trimming new keytops?  I have installed the German one peace tops and fronts
sold by Pianotek and now need to perform the worse part of the job...
Filing these is a time consuming activity!  So I'm thinking the obvious
thing to do is cut the tops flush with the side of the key and round off the
edges and corners afterward.  I don't have a router and don't really want to
get one, so how about a Dremel?  Would that work worth a darn?  Any
suggestions?  I have no plans of going into the keytop business but I have
two other pianos that need tops and I'm to cheap to send the work out.  The
way I see it is I have the time so why not just keep that extra money I
would spend to farm the work out.  Thanks as always!
 
Shawn Brock, RPT
513-316-0563
www.shawnbrock.com <http://www.shawnbrock.com/> 
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