In the Italian tradition of organ building, holes for pipe feet are
always tapered.  Although some used to make it with a V-shaped drill,
almost all organ builders obtained tapering by a cone-shaped incandes-
cent iron.  I currently use the same technique; I have a set of iron
cones of different size.  I heat the cone by a welding torch; when it
becomes red, a number of holes can be burned in few seconds.

It is not necessary that the shape of tapering exactly matches the
shape of foot's tip.  In antique organs, the holes taperings are
conical, while the feets tips are rather dome-shaped.  If the shape of
holes cone has no irregularities, and the tip of the foot is properly
tapered, then the cone will be tangent to the dome in one ring, thus
assuring airtight fitting.  If the feet were tapered in a conical
shape, then the burning iron might have the same taper angle as the
tool that was used for coning-in the feet.

Tim Blyth wrote:

> Why does anyone want to make tapered holes for organ pipe feet ?
> Gavioli, Marenghi, etc. etc. didn't do it, so why bother ?

Although some old builders used to make holes with no tapering, and
those might be let as they are for historical purposes, in my opinion
it is preferable that for new instruments the holes are tapered.  When
tuned by tuning cones, metal pipes are struck with light taps at their
upper end.  Notches are produced at the tip of the foot if it rests on
the sharp edge of an un-tapered hole, and in time it could be damaged.
If the pipe rests on tapered hole, it will tolerate moderate stress
with no damage.

For those who could be interested, my e-mail address is changed;
the new address is  <L.Perretti@isnet.it>

Best regards to all

Leonardo Perretti
L.Perretti@isnet.it