I've tried to stay up on this thread, and if what I say misses anything
already said, I apologize.
I've been interested in the capo bar issue for most of my own 35 year piano
service career. I remember discussing it in the 1980s with Bill Garlick
when he was at Steinway; at that time I'm pretty sure Bill said that
Steinway was hardening the capo. Matt Grossman had also contributed something to
the tech editor section in the Journal in 1984 on TIG welding/reflowing
badly damaged v bars, which I did on a couple of heavily beat up university
Steinways (or had done, unfortunately my welder long since passed after a
couple years of serious health problems stemming from environmental exposure).
The V bars after reflowing were spectacular after surface reflowing and
gentle resurfacing. But I'm getting ahead of myself....
Of course there are a set of problems we face, which can sometimes be
blamed simply on the capo bar. Fred has made that point very well.
There are really two points I want to make, one relating to the
deterioration of the string material itself, the other relating to the capo bar
hardness.
1. Piano wire work hardening: My experience is that in an ordinarily
fine treble (especially the lowest capo section), the first obvious
capo-related deterioration is due to the work-hardening of the wire itself at the
v-bar. I'll never forget my first attempt to prove that idea, many years
before Susan Kline wrote that piece for the Journal....The piano was a restrung
"C" which had been used heavily in a teaching studio. Using the original
wire, I backed the tuning pin off on one side and pulled it up on the other
side. The buzzing and zinging cleared up and the treble was excellent
again. I concluded that stiffness due to work hardening of the string caused
extreme leakage and buzzing at and through the v-bar. This work hardening
at the v-bar leads eventually to string breakage, which should be prevented
ahead of time through restringing (a better solution than my messy little
experiment), but of course schools prefer to wait until 20 or 30 strings
have broken....
2. Capo bar/v bar hardness: It has always been my understanding that
non-insert capo bar hardness is either 1) at the least, part of the expected
hardness of the surface of any cooled cast iron material, or) the result of
deliberate hardening through finishing techniques in reheating the capo bar.
The main point I want to make is that if it is If 1) or 2) I would be very
careful to avoid aggressive re-shaping. I assume that the shape of a v-bar
is not something I want to mess with, except for light surface
preparation.
This seems to be consistent with Fred's approach, whether or not he agrees
with the above.
Of course Ed McMorrow's approach as he has outlined it in his book and
since is a radical departure which looks for optimal performance without regard
for longevity, at least, as I understand it. I remember that when my
brother worked in product planning for Honda, the Acura NSX had just come
out. It had sticky tires that were good for 3,000 miles.....
Regards,
Bill Shull
In a message dated 7/23/2014 12:58:56 P.M. Pacific Daylight Time,
Mail@ConnectedCommunity.org writes:
Much thanks Fred. I'm going to copy your process and keep it. Who knows,
maybe one day I'll need it.
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Giovanni Voltaggio
A440 Piano Service
Website <https://www.facebook.com/A440PianoService>
Austin, Texas
A440PS@gmail.com-------------------------------------------
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Original Message:
Sent: 07-22-2014 18:51
Original Message------
Much thanks Fred. I'm going to copy your process and keep it. Who knows, maybe one day I'll need it.
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Giovanni Voltaggio
A440 Piano Service
Website
Austin, Texas
A440PS@gmail.com
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Original Message:
Sent: 07-22-2014 18:51
From: David Love
Subject: Reshaping the capo bar in situ
I've run into this problem not infrequently over the years. Poor termination in the 1st capo section creating lots of noise, lack of clarity, falseness, weakened tone, etc. The piano in question here was a Steinway B c1998. Attempts to clean up this section prior to my arrival included glue on the front duplex section (the idea being to detune it by adding mass), and felt inserts which quiet it but also kill it. Best option, I decided, was to restring the section and reshape the cap bar in the process.
Basic Procedure
1. Remove dampers
2. Equipment needed: Mirror about 6" x 18" (or thereabouts), mill files (medium cut), wide black felt tip pen, portable lighting to insert into action cavity, damper underlever height platform, wax, stringing materials and tools, etc..
3. Turn the pins counterclockwise about 1.5 turns and remove strings. I then proceeded to make the tuning pin heights somewhat uniform (they weren't) so that when I replaced the strings they would be reasonable close to level. Better to err on the side of too high than too low as you can always tap the pins down if they are too high. It's a pain to uncouple the strings and back the pins out if they are too low.
4. Lay the mirror under the capo bar on the key bed and position lighting in the action cavity to illuminate the bottom of the capo bar. Using the wide felt tip pen mark the edge of the "v" black so you can see what it is you are removing and not removing.
5. Using the files begin to remove material observing what you are doing in the mirror on the keybed. Maintain a consistent angle with the files on both sides of the v-bar and work slowly to reduce the width of the ever narrowing black line. Angle is probably about 30 degrees +/-. I take the line down to about the width of a fine tipped pen, about the same as this font.
6. Once you get the line a consistent thickness all the way across, take some 400 paper and shoeshine the V to clean up the string cuts that are there. Then mark the v-bar again with the felt pen and recapture your uniform and thin black line.
7. Shoeshine the v-bar again with 600 or finer paper. Dress it with some paste wax.
8. Restring the piano using a dummy pin (wrap the coil, remove from dummy pin and transfer), pull 15 - 20 cents above pitch, set the beckets, run a roller gently over the strings to help settle them, pull to 10 - 15 cents above pitch, roll again, pull to 5 - 10 cents above pitch etc, until you get some semblance of stability. Level and mate strings to hammers in whatever manner you prefer, gently set the bends at the bridge pins.
9. Reinstall dampers (of course you set your damper guide before you removed them).
At this pint I like to t10 - 15 cents sharp with the intention of coming back in a few days to a week. Upon returning tune to pitch. Return in two weeks. Tune to pitch. Return in a month, tune to pitch. Return in 2-3 months, tune to pitch. By the next time it will be time to tune the piano again anyway and the strings should be relatively stable if you've settled the bends, coils and beckets.
The process (one capo section) takes about a day not including the return visits for tuning. YTMV.
On this particular piano (and many others that I've done) the difference was very noticeable. The pianist was shocked at how much difference it made in terms of cleaning up this section and creating greater tonal uniformity from the tenor through the treble. I've encountered many Steinways (and other pianos as well) with this type of problem. Interestingly, newer Steinways seem have the problem more often than even vary old ones, at least in my experience. The standard for v-bar shaping out of the factory seems "loose". It's a bit of a hassle and not without cost to the customer but if you are having noise problems as described it's something to consider and not difficult to do in the home.
Interestingly, the problem of noise was (is often) less pronounced in the upper capo section. The relationship between the speaking and duplex lengths might have something to do with that.
A fine filing of the hammers to reduce mass and excess felt in the upper sections will also help to add clarity and sustain.
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David Love RPT
www.davidlovepianos.com
davidlovepianos@comcast.net
415 407 8320
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