Burnishing Graphite

[David Love]

I've done a similar procedure on Tokiwa wippens (Renners come beveled) and I
think it's a good idea for a better feel during escapement and better return
of the jack under the knuckle.  I don't think you need to spend that much
time burnishing.  When I dag bridgetops I burnish with a piece of hammer
felt.  It doesn't take much to bring out a shine.  Similarly, when I have
done the jacks, I take a piece of hammer felt cut into a wedge (felt mutes
bought from the supply house), press it down on the balancier and just slide
it back toward the flange so that it swipes the back of the jack that has
just been beveled. I use the felt mutes to apply the dag as well.  The
tapered end makes a very nice brush when cut a bit narrower.  A couple of
times over each one goes very fast and seems to be plenty.  The edge will
continue to burnish in playing as the jack slides on the knuckle so I don't
think you need to worry about it that much.  I'm not sure how they do it in
production.


David Love


----- Original Message -----
From: "Jon Page" <jonpage@attbi.com>
To: <pianotech@ptg.org>
Sent: August 04, 2002 6:29 AM
Subject: Burnishing Graphite


I decided to round the back edge of the jacks on a new set of wips prior to
installation.
After meticulously detailing the edge with an emery board (rough then fine)
I gave them two coats of Dag.
Then put a 1/8" drill bit in the Dremel Tool backwards so as to burnish
with the shank.

What a nice job it did, shined up the rep lever too. It got me to thinking
about how the graphite is burnished in production.
Anyone know? It might speed things up for next time.

I was also thinking that using the backside of the sanding disk would
burnish nicely for jacks which have been removed.

As far as easing the back edge of the jacks, is there an easier way than to
file/sand? Would the sanding disk (metal portion)
ease this edge as well or faster than hand working?

I plan to experiment with a larger diameter shank next time, something
along the lines of the arbor on the buffing wheel
after it has been cleaned and polished well.

In any case... I'd like to hear some expedient ways to ease the back edge
of the jack both installed in the wip and freestanding.

Regards,

Jon Page,   piano technician
Harwich Port, Cape Cod, Mass.
mailto:jonpage@attbi.com
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