Broken tap

[Brian Trout]

You've got quite a few good suggestions so far.  Penetrating oil in the hole
to lube, just in case it starts to move.  Tapping from top and bottom, could
be both ways repeatedly may loosen enough to turn.  The Dremel tool to cut
the slot in the top of it for a screw driver blade...

Have you thought about instead of trying to heat the plate... what might
happen if you took a little dry ice and put right on the end of the tap?
Could that be enough to shrink the little sucker just enough?  If it didn't
work, it wouldn't cost much, but if it did, there wouldn't likely be visible
heat marks from heating up the plate.?

Just some random thoughts.

Good luck with this one.  It's a toughie.  But when it's fixed, you'll have
an experience that money can't buy! :-)  It's those kind that'll make you a
better technician.

Hope you have a great holiday weekend.

Brian Trout
Quarryville, Pa.

-----Original Message-----
From: ANRPiano@AOL.COM <ANRPiano@AOL.COM>
To: pianotech@ptg.org <pianotech@ptg.org>
Date: Saturday, May 29, 1999 10:36 AM
Subject: Broken tap


>A customer was referred to me by a very good technician who had the miss
>fortune of breaking a tap while retapping agraffe threads.  The tap broke
off
>nearly flush with the plate.  This is a S & S S? circa 1920's.  It is the
>fourth agraffe in the tenor section.  The tap is firmly imbedded into the
>plate.  It will not turn.  I made a tool with two rods to fit into two of
the
>four flutes to attempt turning it out.  The rods broke.  Is there a
>commercially available broken tap removing tool?
>
>I attempted to drill the tap out.  My titanium bits did little.  Though the
>grinding bits I used to flatten out the top seemed effective in removing
>material.  Is there a solution here?
>
>The customer does not have enough money for rebuilding the piano (which it
>could use) so removing the plate and coming in from the bottom is out.
>
>My last idea (which I don't care for) is to drill a new agraffe hole
infront
>of the old.  There is plenty of room in the plate.  Will this cause any
undue
>weakening in the plate, and how badly will the tone on the now 1/2 - 3/4
inch
>shorter be affected?
>
>I know this is not your everyday type of repair, but any input would be
>greatly appreciated.
>
>Andrew Remillard
>