Pianotech

Subject: Broken Agraffe Repair

1.  Broken Agraffe Repair

Posted 01-20-2012 16:33
Peg came home from a service call for "a note that's not working" ----- turned out to be a broken agraffe. Piano is a Steinway B about 20 yrs. old, note is A39. The remaining stud is a bit uneven at the top and a portion does stick up above the hole a tad.

The tool I usually use to extract the stud is a slender modified screwdriver, the tip of which has been ground in such a way as to leave two triangular sharp points. After applying a few drops of WD440 to the stud my procedure is to firmly hammer the the screwdriver points into the top of the stud so as to gain some purchase, then turn it out. Without the agraffe head on top the stud should turn freely, but it doesn't always as the thread engagements are often somewhat locked. Sometimes turning it down at bit will unlock it, then it backs out easily.

Years ago I gave up the (usually) disastrous procedure of using small drills and easy outs. Anyway, you get the picture. Now, does anyone have a new idea on this, or tool, or whatever?

Thanks for your input.

Nick

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Nick Gravagne, RPT
Mechanical Engineering
Nick Gravagne Products
Strawberry, AZ 85544
gravagnegang@att.net
928-476-4143


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2.  RE:Broken Agraffe Repair

Posted 01-20-2012 17:22
If the hole goes all the way through the plate, same tool from the bottom will be pushing the threaded section out (as opposed to "pulling" it up), which is better mechanically. Your pushing on the screwdriver to get purchase is actually helping the extraction (it is in the same direction) rather than working at cross purposes. This assumes a short enough screwdriver handle to fit in the action cavity, and a thin enough blade to fit entirely in the hole.

But I often find I can simply remove one using an awl, finding a rough or raised spot out near the circumference and tapping with a light hammer, angling it so it will be turning the stud in the right direction. Once it is out a bit, it might simply be possible to stop tapping and turn it out by pressing the awl's point into its crevice. 

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Fred Sturm
University of New Mexico
fssturm@unm.edu
"The true sign of intelligence is not knowledge, but imagination." - Einstein
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3.  RE:Broken Agraffe Repair

Posted 01-20-2012 22:48
Nick,

Recently encountered a broken agraffe stem that would not budge with that type tool you mentioned. Absolutely frozen in place. Here is what I did to get it out.

With the smallest drill bit I had, I started a hole as close as possible to the center of the broken stem. Once I had established a beginning indentation where that small bit would not wander, I moved to the next size drill bit to make the hole a little larger and a little deeper, always keeping in mind to stay perpendicular so as not to damage the threads in the plate. Then I moved to the next size bit to make the hole even larger and deeper eventually penetrating a hole through the entire stem. Very slow drill speed, just enough to cut, removing the brass shaving often.

I then tried a reverse drill bit (Isaac Sadigurky's idea) with a T-handle very carefully to see if would bite and start the frozen stud to move. No go at all. I definitely felt like that bit might break before the frozen stem would break loose, which, of course, would further complicate the situation, so I quit that approach.

Next step was to take use easy out extractor and the T-handle. No drill. I applied pressure as gently as possible waiting for any sign of breaking loose all the while not applying so much that I was assured the easy out would not break.

Applied a little more pressure, backed off, applied a little more pressure, backed off again. Next time I applied pressure that beautiful sound of the threads breaking loose occurred!!

From then on it simply unscrewed like it should. I may have used a lubricant with using the drill bits, but I don't actually remember now. I know if I did, it was definitely not WD-40. More likely a bit of Protek.

Hope this helps.

Keith McGavern, RPT
Shawnee, Oklahoma, USA
tune-repair@allegiance.tv
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4.  RE:Broken Agraffe Repair

Posted 01-21-2012 00:07

Just as an aside...I'm really looking forward to John Zeiner's class in Nashville this April on this very topic.  I've had a few of those nasty agraffes on Steinway M's and one was easily remedied.  The other, sad to say was incredibly difficult to where I needed to retap the threading.

I too Kieth, approached the second in the same manner as you've described but to no avail, brass was left in the threading.  Needless to say, it was a difficult day :)


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Dave Swartz, RPT
Cory Products, LLC
www.corycare.com
dave@corycare.com
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5.  RE: Broken Agraffe Repair

Posted 15 days ago
With the smallest drill bit I had, I started a hole as close as possible to the center of the broken stem. Once I had established a beginning indentation where that small bit would not wander, I moved to the next size drill bit to make the hole a little larger and a little deeper, always keeping in mind to stay perpendicular so as not to damage the threads in the plate. Then I moved to the next size bit to make the hole even larger and deeper eventually penetrating a hole through the entire stem. Very slow drill speed, just enough to cut, removing the brass shaving often.

No one mentioned using a punch. It sure makes it easier to stop those wandering drill bits!
-chris
#caveman


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I have a piano in my Nuclear Fallout Shelter, and my competitors don't. How silly is that?

chernobieffpiano.com
865-986-7720
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6.  RE:Broken Agraffe Repair

Posted 01-21-2012 14:53
Nick,

I realize what I said was not a new idea or tool, but it was a new approach to dealing with an old issue.

Equally, I want to add, should what I did not have worked, there are still further options to remove that broken stem without damaging the threads in the plate. Patience and understanding is the total key to extraction.

Keith McGavern, RPT
Shawnee, Oklahoma, USA
tune-repair@allegiance.tv
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7.  RE:Broken Agraffe Repair

Posted 01-24-2012 14:42
  |   view attached
I got more, Nick, for you and anyone else interested. One of those further options I mentioned.

A video clip of a new, but very, yet not very recent tool, for broken agraffe stems that I have had in my possession for many years.

See attached video clip.

Keith McGavern, RPT
Shawnee, Oklahoma, USA
tune-repair@allegiance.tv
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8.  RE:Broken Agraffe Repair

Posted 01-22-2012 00:44
Sears has a good screw extractor kit that consists of a set of hardened and sharpened "Phillips" style bits that cut into a soft part and extract a screw.  They work, though not perfectly or always.

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Blaine Hebert
Duarte CA
626-795-5170
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9.  RE: Broken Agraffe Repair

Posted 15 days ago
Hi All,

Thanks for this discussion thread - I have a client with a Steinway B with a broken bi-chord agraffe.

When doing this repair, is it possible to use the existing strings or are they toast as well and must be replaced as part of the repair?

I haven't found any references to this aspect of the repair . . .

Thanks much.

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[Barbara] [Bernhardt]
[Piano Technician/Co-Owner ]
[GF Music, LLC]
[Montrose] [CO]
[(970)209-8817]
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10.  RE: Broken Agraffe Repair

Posted 15 days ago
Hi Barbara, I've used the same bass string providing it responds to the straightening required to feed it through the new agraffe.  On the other hand if you really want a high end job you can be proud of, replace them. 
 
Replacing the strings helps eliminate the hazard of possible breakage during reinstallation.
 
Using the same strings saves the customer some cost until the string possibly fails after reinstallation.  The process that follows may incur some expense out of your pocket.  Represent the job fully to the customer prior to the work being started then let them decide what route they'd like to try.
 
There's a certain level of gratification I get after successfully replacing broken agraffes.  Good luck and I hope the job goes well for you.
 
Lar
 
 
 
 





11.  RE: Broken Agraffe Repair

Posted 15 days ago
When removing a bass string, apply tension to the speaking length so that the coil does not turn into a spring and break its own becket.
Remove the damper so you have one less thing in the way.
You won't get perfectly straight strings, and don't straighten out the becket bends, you can fit them through the agraffe holes.
Feed a string through the agraffe, recoil it on a dummy pin as well as you can, fit it back on the original pin and carefully work it back into a good coil.

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Ed Sutton
ed440@me.com
(980) 254-7413
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12.  RE: Broken Agraffe Repair

Posted 15 days ago
Which bi-chord is it? There are two sizes of bi-chord agraffes. For wires with larger wraps (first few bichords, maybe 4); the holes are further apart to allow the damper to settle in.

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Regards,

Jon Page
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13.  RE: Broken Agraffe Repair

Posted 15 days ago
Here's a photo of it - G-1.



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[Barbara] [Bernhardt]
[Piano Technician/Co-Owner ]
[GF Music, LLC]
[Montrose] [CO]
[(970)209-8817]
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14.  RE: Broken Agraffe Repair

Posted 15 days ago
From the looks of the difference in string spacing between G#1 and A1, it would appear that Jon is right about there being four wide-double agraffes at the bottom of the bi-chords (F1-G#1) on this piano.

Alan

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Alan Eder, RPT
Herb Alpert School of Music
California Institute of the Arts
Valencia, CA
661.904.6483
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15.  RE: Broken Agraffe Repair

Posted 15 days ago
My go to tool for removing broken agraffe stud is a reverse twist bit, (a "left" hand bit some call it) about 3/16" diameter in a variable speed, reversible drill motor. Center punch the stud and start drilling very slowly. The bit will "bite" into the brass and thread the stud out.

First steps are the same as Ed Sutton's. First four bichords in steinway's are wider than the rest.

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Edward McMorrow
Edmonds WA
425-299-3431
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16.  RE: Broken Agraffe Repair

Posted 15 days ago
Edited by Jon Page 15 days ago
To answer your question, the strings can be reused if you pull with a screw driver to uncoil. You need to carefully open the becket a bit to pass thru the hole. There is a good chance that the wire will break at the bend, no problem. Create a new bend for the becket utilizing a few pliers. Reset the coil on a dummy pin. Don't forget to put a twist in the wire.

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Regards,

Jon Page


17.  RE: Broken Agraffe Repair

Posted 14 days ago
Jon,

Where do you place the screwdriver when you do the pulling - on the core wire just pin-side of the winding? I presume you are using the shaft of the screw driver to gain leverage and purchase on the wire without nicking it - correct?

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[Barbara] [Bernhardt]
[Piano Technician/Co-Owner ]
[GF Music, LLC]
[Montrose] [CO]
[(970)209-8817]
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18.  RE: Broken Agraffe Repair

Posted 14 days ago
After you remove the coil from the pin, place a screw driver blade thru the coil (where the pin was) and pull to straighten. There will be a curve left in the wire but that's OK. If the old agraffe does not make it around the becket bend, expand the angle a bit with pliers.

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Regards,

Jon Page
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19.  RE: Broken Agraffe Repair

Posted 14 days ago
A dummy pin is a tuning pin which makes the coil which is then transferred to the installed pin. The one I like is one which is cut ~1/4" below the becket hole with a slot is cut up to the hole. A Dremel Tool Cut Off Wheel makes quick work of it.

This lets the coils slip off the pin. With treble wire, you need to turn the pin in reverse to expand the coil a little to aid in transferring the coil. For bass core wire, you need to expand the coil plus pry the becket away a bit with a screw driver, the wire is stiffer and more difficult to transfer.



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Regards,

Jon Page
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