Clean - don't ream!

[Al Jeschke]

Rob & List,

My choice would be to ream, although I have not used the rifle cleaning
brush method.  However, I can imagine what the stiff bristles of the brush
can do - that of trimming away more wood than required when used to
`somewhat' size the hole for the pins to be installed.  Much depends on just
how the brush is used.  When repinning, or restringing pianos and using the
original pinblock, I have always reamed when there was the need to size the
tuning pin holes.  Precision is the answer to the proper torque of tuning pins.

For preparing to repin my first piano I ordered a spoon bit reamer, which
was quickly put aside because of (in my estimation) its poor performance.  I
then made up my own reamers from high speed drill bits.  I could make these
to exact requirements and use the 3/8 drill to do the laborious part of the
work.  Being that tuning pins from the same box can vary in diameter, I
could sort the pins, and by using properly sized reamers, have the torque
come out the same throughout.

To save bandwidth, I will not describe the making of reamers here.  With the
proper equipment and a little ingenuity the reamers can readily be made.  If
interested, you can e-mail me for details.

Al Jeschke RPT
Calgary, Alberta
=====================

You wrote:-

"Clean - don't Ream" was the title of a technical done at a long-ago seminar
by Wendell Eaton and ? (I forget who).  Their premise was that cleaning
tuning pin holes with a rifle cleaning brush chucked up in a drill was a
better way to approach the repinning problem than reaming the holes.

I've been less than happy with some of the repinning work I've done over the
years......none have been underpinned, but there have been some jumpers and
a lot of supertight pins,  particularly where I've not done anything at all
to clean or ream the holes.

Now I have to repin the bass on a Steinway "O".  It's never been touched,
and  a few of the pins wouldn't hold at all, so I tapped them very lightly
just to hold them for a week till I get down to work.

As I consider reaming the holes, I checked in the Schaff and Apsco
catalogues for reamer specs, and I note that the tolerances between
recommended reamer size and pin size are not the same for both suppliers:
(Pianotek's reamers come in assorted sizes, but no pin sizes are mentioned
in the book).

For 3/0 pins (nominally .286) Schaff suggests a .276 reamer, while Apsco
lists a .280 reamer.

For 4/0 pins (nominally .281) Schaff's reamer is .291 and Apsco's is .285.

I know from drilling new pinblocks that there is a hell of a difference in
torque between  holes drilled at  .010 tolerance and those at .006
tolerance.

So what's the advice of the list on this?  Should I ream, clean, or just
plug 'em in? (I'd be using 4/0 in the bass, probably.  And if reaming is
best, what size reamer should I use?

Rob Stuart-Vail