an actual piano question

[Don Mannino]

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From:       INTERNET:PNOTNR@aol.com
Sent:       Friday, October 13, 1995 7:09 PM
To:   Multiple recipients of list
Subject:    an actual piano question

Gordon Large wrote:

>>I need to know about using tuning pin reamers.  I'm repinning yet another old
upright, and this beauty has had about a dozen 3/0 pins put in over the years.
If I go to 4/0 pins, I should ream out the holes first to make them all uniform,
but why would I use a reamer and not a drill bit for 4/0 pins.  In the supply
catalog (APSCO) they list a reamer for 4/0 at .285" but a drill bit for 4/0 is
.281".  (As you can tell, I've never used a tuning pin reamer) Why are they
different sizes?<<

>>Also, how do you use the reamer?  On a new block one is careful to control the
speed of the bit, the time the bit is in the block, the temperature of the bit,
etc.  Is this the case with a reamer as well?  Or can I just hog
away?<<

Gordon,

First, don't necessarily trust what the supply house sells as the correct item
or size. Although there are certainly exceptions, it seems that piano supply
companies are not always run by technicians, so what they sell is often what is
conveniently available to them from _their_ suppliers.

The biggest disadvantages to reaming are lack of control of the drilling angle
and poor bit cooling. Some technicians feel it is _necessary_ to ream all
pinblocks when repinning, but I feel that only those with a real problem should
be reamed.

Multiple sizes of tuning pins in one block should be evened up as you suggest,
but don't forget to consider why the different sizes were put in - some
technician (perhaps misguidedly) felt the need to put in some pins, which
indicates problems in the block.

A proper pinblock drill is the best reamer. I'm sorry, I've forgotton the
technical term for for the type of drill, but the angle of the fluting is
different from a standard bit. There are more cutting spirals per inch, and the
edges have been sharpened to help smooth the hole. Somebody jump in here and
supply the name for it.  The reason that special reamers (such as the spoon bit
type) are sold is because a regular drill can create spiral grooves when driven
down into the existing hole.  This isn't the end of the world, but it isn't too
good.

Use a lighter weight drill motor that still has enough torque to do the job. The
lighter the drill, the quicker your hands will find the right angle of the hole,
and the less opening up of the top of the pin hole you will do.  If you can, rig
up a cooling hose on the drill motor somehow, or at least have a blowing air
source nearby to hold the drill bit in after each hole is reamed.

Start drilling each hole with light pressure, allowing the drill to settle into
the angle without forcing it. Then quickly go all the way in and back out in no
more than 2 seconds.  Cool the bit and move on.

Other things to consider: Plug the holes and re-drill, or replace the pinblock.
Replacement isn't always so terrible in an upright, but it depends on how the
piano was built.

Don Mannino, RPT
74473.624@compuserve.com