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 -------------------------------------------
Original Message:
Sent: 01-20-2012 16:33
From: Nicholas Gravagne
Subject: Broken Agraffe Repair
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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