Pianotech

Expand all | Collapse all

A Broken Agraffe

  • 1.  A Broken Agraffe

    Posted 03-01-2024 22:02

    I am working on 1915 Steinway Model O with a broken agraffe at C#5. I was unable to manually turn it out (like I normally do) so I drilled through the remaining core to use a #2 EZ-Out. It won't turn, and I don't want to take a chance on breaking off the EZ-Out with a hard twist. See the picture.

     

    Are the agraffes on this piano 7/32"x36 or 1/4"x36? I lean toward, next, drilling and trying an EZ-Out #3. If that fails, then drilling and tapping for the new agraffe. Any help/suggestions would be appreciated. Regards, Norman.

     



    ------------------------------
    Norman Brickman
    Potomac Piano Service
    Potomac, Maryland
    potomacpiano@verizon.net
    https://potomacpiano.com
    (301) 983.9321
    ------------------------------


  • 2.  RE: A Broken Agraffe

    Registered Piano Technician
    Posted 03-02-2024 00:21

    Hi Norman:

    I have had very good luck using left-handed drill bits.  Easy outs are treacherous, as they can easily break off in the hole.  If your hole is basically centered, use a small left-handed bit in a cordless drill, and go veerrryyy slowwwllllyy.  At some point, it will catch and twist the stud out.  Start small, larger if it doesn't work.  Don't use a regular corded drill unless it will go slowly.  Too small could break off.  Take your time, and if you have a good light and a magnified visor, it helps to see what's going on.  Harbor Freight has a set of lefty drills for cheap, I recently bought another set to replace one I had for years.  I've never had a failure with them.



    ------------------------------
    Paul McCloud, RPT
    Accutone Piano Service
    www.AccutonePianoService.com
    pavadasa@gmail.com
    ------------------------------



  • 3.  RE: A Broken Agraffe

    Posted 03-02-2024 06:29

    Paul, thanks for the advice. I just ordered a set of the left-handed bits. I have the reversible battery clutch drill, but unfortunately its chuck is a little bigger in diameter than what I was using and I am up against the plate support – it will be close, and I was unable to find a long set of left-handed bits. Any thoughts on also using a couple drops of WD-40?



    ------------------------------
    Norman Brickman
    Potomac Piano Service
    Potomac, Maryland
    potomacpiano@verizon.net
    https://potomacpiano.com
    (301) 983.9321
    ------------------------------



  • 4.  RE: A Broken Agraffe

    Registered Piano Technician
    Posted 03-02-2024 06:34

    A few drops of 3-1 Oil may work better than WD40.



    ------------------------------
    -Phil Bondi
    ------------------------------



  • 5.  RE: A Broken Agraffe

    Registered Piano Technician
    Posted 03-02-2024 13:28
    Liquid wrench or a similar brand, you can buy at a auto supply stores.

    John





  • 6.  RE: A Broken Agraffe

    Registered Piano Technician
    Posted 03-02-2024 08:37

    I don't know how big your drill chuck is, but I have a hex drill chuck which fits an impact drill.  It's smaller than the keyless chuck you'll likely have on your drill.  Google "impact hex drill bit chuck", note the "images" and you'll see what I mean.  It might be small enough to get in there.



    ------------------------------
    Paul McCloud, RPT
    Accutone Piano Service
    www.AccutonePianoService.com
    pavadasa@gmail.com
    ------------------------------



  • 7.  RE: A Broken Agraffe

    Registered Piano Technician
    Posted 03-02-2024 09:27

    Norman,

    That O will have 7/32" agraffes. If the left-hand drill bits don't work, you can always drill out the stump as far as you dare go (not damaging the plate's female threads) and then drive the remaining brass out with a steel punch, blunt-ended, of suitable diameter. The brass will yield long before you damage the plate casting. Then, use the 7/32 x 36 tap to clean the brass shards out of the plate's threading. This may sound horrific, but it really isn't.



    ------------------------------
    David Hughes RPT
    Vintage Case Parts
    Glyndon MD
    (443) 522-2201
    ------------------------------



  • 8.  RE: A Broken Agraffe

    Registered Piano Technician
    Posted 03-03-2024 15:43

    ...and just in case those original 7/32" x 36 threads happen to get damaged in the process of removing the broken agraffe, fear not! You can easily re-tap for a "modern" 1/4" x 36, without even drilling the old hole. After all, 1/4" is only 1/32" larger that 7/32", which means you would be increasing the hole/thread by only 1/64" all the way around.

    Of course, this never happened to me, but I know a guy... ;-)

    Alan



    ------------------------------
    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
    ------------------------------



  • 9.  RE: A Broken Agraffe

    Registered Piano Technician
    Posted 03-02-2024 09:31

    If you manage to get a drill bit in there, sometimes you'll find yourself drilling farther and farther down, even coming out the other end.  Just use the next size up.  Often I find that I'm halfway into the stud and it finally bites.  Those Steinway agraffes are tight in there, as I have experience.  You might also try using a freeze spray or heat it up with a soldering iron or mini torch.  I'd try penetrating oil like PB Blaster, but I'm not sure it would help that much.  Tight is tight.

    I have also seen long shank left handed bits on Amazon and other places.  Might be worth a call to a local tool dealer.  Good luck!



    ------------------------------
    Paul McCloud, RPT
    Accutone Piano Service
    www.AccutonePianoService.com
    pavadasa@gmail.com
    ------------------------------



  • 10.  RE: A Broken Agraffe

    Member
    Posted 03-02-2024 09:46

    You can try to fit your drill with a 90 degree chuck (AKA right angle) designed to get in tight spaces. I have a Milwaukee M12 that has interchangeable chucks including a right angle chuck. The cordless Dewalt I have has a gyro in it the more you twist your wrist with your finger on the trigger the faster it goes . It gives extremely good control. Both drills have clutches 



    ------------------------------
    James Kelly
    Owner- Fur Elise Piano Service
    Pawleys Island SC
    (843) 325-4357
    ------------------------------



  • 11.  RE: A Broken Agraffe

    Posted 03-02-2024 10:48

    All excellent help -- appreciated. I just ordered a 1/4" hex drill chuck – should give me the plate clearance that I need without use of a long bit (one needs to be careful not to get a threaded one that is not meant for counterclockwise use!). I have a 7/32x36 tap on order, and I already have a good set of steel punches that I'll bring with me if needed. It might be a couple weeks before I get status back to you all. Thanks again. 



    ------------------------------
    Norman Brickman
    Potomac Piano Service
    Potomac, Maryland
    potomacpiano@verizon.net
    https://potomacpiano.com
    (301) 983.9321
    ------------------------------



  • 12.  RE: A Broken Agraffe

    Posted 03-02-2024 20:26

    Maybe one other question. Normal procedure in drilling in brass is to grind/file the leading tip of the drill bit a little (parallel to the axis) so it doesn't grab on the softer metal. I already have a 7/64" pass hole in placer. Grinding the tip of the bit will somewhat decrease the dual use of the drill bit as an EZ-Out, but I think that is better than risking a hard seizure. Agree? 



    ------------------------------
    Norman Brickman
    Potomac Piano Service
    Potomac, Maryland
    potomacpiano@verizon.net
    https://potomacpiano.com
    (301) 983.9321
    ------------------------------



  • 13.  RE: A Broken Agraffe

    Registered Piano Technician
    Posted 03-02-2024 21:47

    You may want to first use a transfer punch to locate the center of the plate hole.



    ------------------------------
    Parker Leigh RPT
    Winchester VA
    (540) 722-3865
    ------------------------------



  • 14.  RE: A Broken Agraffe

    Registered Piano Technician
    Posted 03-03-2024 20:51

    Stop, throw away your EZ out.  Drill all the way through the agraffe with a regular bit, maybe 3/16" to start, then go to the next size bit until you've removed most of the agraffe.  If you cut into the threads a little bit on one side don't worry about it too much, there's still plenty left to hold the agraffe.  These are 7/32 diameter agraffes, if you really screw it up you can drill and retap for 1/4".  Once you have most of the agraffe drilled mostly out (there will be a thin part of the agraffe remaining, just use a sharp awl and  peel away the rest of the agraffe from the inside of the hole.  Retap and you're in business.

    Hints: 

    1. Just use a plain carbon steel l bit or maybe high speed.  Don't go to really hard bits (the harder the more brittle) you don't want to break off the drill inside the agraffe.  Plain carbon (cheapest drill) are fine.  
    2. Use a cutting fluid or oil when you drill so the bit doesn't snag and snap off.
    3. The reason to drill all the way through the agraffe is so that if you do break off a bit you can often punch it out form the bottom (or top).
    4. Brass is very soft, you don't need any kind of hardened drill
    5. General rule, if you can't get the stem of the agraffe to turn just by tapping on it from the side and trying to rotate it using a sharpened screwdriver, or similar, you probably won't get it to move with an EZ out and breaking off an EZ out is a major pain.  
    6. Also, don't take the strings or damper out.  Just loosen the tension, move the strings to the side and then after you have the replacement in, remove one string at a time from the tuning pin, snip off the becket, straighten the wire by inserting a rod (screw driver shank will do) and pulling on it to unwind the coils.  Then move the strings one at a time to the new agraffe.  Otherwise you're just making extra work for yourself.  Unless, of course, you charge by the hour ;-)


    ------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    ------------------------------



  • 15.  RE: A Broken Agraffe

    Posted 03-16-2024 06:37

    Thanks again to all for your assistance. I just completed the job yesterday. I used left-handled bits but I still had to move up to a 5/32" pass hole before I was able to manually work out the old stub. Using a drill with a clutch was very useful. Then I used a 7/32"-36 tap from Schaff to clean out the hole and put a new agraffe in, and reused the old strings. 

     

    I did slightly file the tip on the new drill bits before using them, which is standard procedure when drilling through brass. And a question – my understanding is that a 12-36 tap (or die) is the same as a 7/32"-36 – is that correct? Regards, Norman.



    ------------------------------
    Norman Brickman
    Potomac Piano Service
    Potomac, Maryland
    potomacpiano@verizon.net
    https://potomacpiano.com
    (301) 983.9321
    ------------------------------