The traditional boxwood bushings can be put in either with the grain
running along the bushing, as in a normal dowel, or with the grain
crosswise, which is much less common. If it's crosswise you make it go
across the grain of the pegbox, to resist splitting. In either case the
new peg hole must be drilled off center, so that the peg itself
overlaps the glue line and acts as a locking key to keep the bushing
from rotating in the hole. If you don't the only thing holding the
string tension is the glue line, and it won't hold for long.
The shaving method, usually called a 'spiral bushing', has become much
the prefered way of doing it these days, from what I can tell. It
entails the minimum of removal of original material from the peg box,
and you don't have to drill new peg holes off center. In many cases you
can clean out the original holes with a reamer and put in a bushing
that's practically invisible, it's so thin.
I like to wet the edge of a straight-grained maple board and then take
a shaving off it with a sharp plane. Wetting it keeps the cap iron from
breaking the wood grain and curling up the chip, so it's much stronger.
Make sure the strip is a good bit wider than the thickness of the
pegbox cheeks, as wraping it around a cone will cause it to
progressively migrate toward the thick end.
I've made a little plexiglass pin that the glue won't stick to with the
same taper as my reamer . I get some Titebond onto the shaving, wrap
it around the pin, and shove it into the hole ASAP. Once the glue has
set up I clean up the excess glue and wood, and ream the hole out to
fit the peg. Sometimes this can be a bit frustrating, as the shaving
sticks to your fingers and doesn't go where you want it to, but with
some practice it gets easier.
Some folks make tapers out of soft wood, or get cheap pearwood pegs,
wrap the shaving on dry, stick it in the hole and flood the area with
cyanoacylate. Then they just drill out the taper. This can be very
quick.
There doesn't seem to be much worry about the use of non-authentic
glues, such as Titebond or CA: the bushing is seen as disposable, and
since it's minimally invasive and easiliy replaced in any case nobody
much cares, so long as it works.
Alan Carruth / Luthier