---------------------- multipart/alternative attachment Phil, =20 I wrote an article about just such a problem for the Chicago newsletter. =20 Here it is: =20 Things Which go Crack in the Night =20 It usually begins with a call like this: =E2=80=9CI was only walking throug= h the=20 living room=E2=80=9D or =E2=80=9CSuzy had just finished Twinkle, Twinkle whe= n the piano made a=20 huge bang, it sounded horrible, you had better come and look at it right =20 away.=E2=80=9D =20 Though relatively rare, a broken agraffe can present quite a collection of =20 difficulties in repairing, yet if you are careful and take your time, all bu= t =20 the worst situations are easily repaired. =20 The easiest scenario to repair is when the top of the agraffe breaks off at=20= =20 the string holes. Simply remove the strings, grab the remainder of the =20 agraffe with vise grips or pliers and unscrew. If the stem comes out clean= ly,=20 simply tap the hole (more about this shortly) and install a new agraffe. W= hen=20 selecting the correct replacement part be aware of differing stem lengths a= nd=20 diameters. The threads have been pretty standardized on most modern=20 instruments so the choice is pretty straight forward between American and m= etric. =20 If the agraffe breaks below the shoulders, first try turning the stem with =20= a=20 screwdriver, tapping on the screw driver with a light hammer. If it doesn= =E2=80=99 t move right away, stop, it is not going to come out this way. =20 Next drill a 7/64=E2=80=9D or 1/8=E2=80=9D hole in the stem and use an Easy-= Out =E2=84=A2 to remove =20 it. If the stem comes out, tap the hole and install the new agraffe. If=20 the stem does not come out, go up a step with a 5/32 drill and try the #2 =20 Easy-Out =E2=84=A2 again. If this fails, it is decision time. Any addition= al drilling=20 and you run a great risk of damaging or destroying the threads in the plate= . =20 If the original stud size was 7/32=E2=80=9D this is an easily solved proble= m. You=20 will need to drill and tap the hole properly but you can go up a size in ag= raffe=20 stem. However, if you are already at the =C2=BC=E2=80=9D stem size and you= damage the=20 threads beyond use, you will need to repair the harp to accept the proper=20 agraffe stem. =20 In order to repair damaged =C2=BC=E2=80=9C agraffe holes, drill out the hole= to accept a =20 3/8=E2=80=9D threaded brass plug. This hole will need to be tapped to accep= t the =20 thread of the plug. The plug can be a brass rod you have cut threads onto,=20= a=20 brass machine screw, or a set screw (which is the best solution overall, =20 especially in centering the new agraffe hole.) Either choice will involve =20= some=20 grinding to remove excess material, the set screws are generally the least =20 amount of work. Use a product like JB Weld =E2=84=A2 to cemented the plugs=20= into the harp.=20 Do a dry fit to insure everything fits properly and install and cement. =20 Allow the cement to cure. Drill the plug out to accept the new agraffe, ta= p=20 and install. =20 =20 A word of caution regarding taps and Easy-Outs =E2=84=A2 - they break. And=20= when=20 they do, you have a bigger problem than you began with. Taps are used to c= ut=20 new threads inside a hole or to clean up damaged threads. As you slowly tu= rn=20 the tap in the agraffe hole, back it out about =C2=BC turn every full clock= wise=20 turn or whenever the resistance increases. This will clear the shavings wh= ich=20 will eventually bind the tap. Go deep enough to safely accept the new stem= =20 length. =20 There are other issues which will be covered in the future which you may ru= n=20 into, such as the new agraffe standing taller than the original or less =20 common lower than the original, not to mention the whole problem of alignme= nts. =20 =20 And lastly, sometimes the underlever can be damaged as the strings move up,=20= =20 so don=E2=80=99t forget to make sure it is still in one piece. ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/7c/eb/40/97/attachment.htm ---------------------- multipart/alternative attachment--
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