It seems that most new builders (myself included) make the largest part
of their pipe bodies of a softer wood, say pine or spruce, and the
front of a harder wood like poplar or maple.

Straight grain and hard wood make it easier to cut the mouth with no
mistakes.  It's also easier to cut a sharp upper lip at the mouth, if
made from a hard wood.  Violins practically demand it, while the front
on flute pipes can be made entirely of softer woods, if desired.

Maple is a material well-suited for blocks and caps, and a piece of
maple may be laminated to softer wood when making blocks for larger
pipes.  I have had difficulty with yellow pine.  I don't use it when
I can avoid it, and even then I would only use it in the sides or backs
of the pipes, where the amount of hand work needed is at a minimum.

I have seen pipes made by Don Stinson which are completely made of
poplar;  he has had good results with them, and I have made some in the
same manner.  I even have some that I made which were made of odds and
ends, with several different species of wood used in them, and I cannot
tell the difference (not that I advocate this type of construction in
work of the highest grade, mind you).

I don't think that old wood necessarily makes mellower-sounding pipes,
but well-aged wood is much more stable than that which is not.  Pipes
made from well-seasoned stock are likely to have fewer incidents of
joint separation or checking.  I try to have enough wood around my shop
that it can sit for a year or so even after I buy it (as seasoned wood
from the lumber company), or I try to use reclaimed organ pipes as
material for new ones.

Knots aren't much of a problem if they're relatively small and air
tight unless the wild grain about the knot gets into some area that
requires work (i.e., the mouth, tuning slot or nodal hole area).  If
the knot area is small, tight, and can be planed without tearing chunks
out of the surface of the wood, then use it.  I have a picture of a
large, well-known Gavioli with a huge knot in one of the accompaniment
pipes.

Simple glued butt joints are the most common, although I have found
lock joints used in large pipes on occasion, particularly in large
stopped flutes, where aggressive tuning might loosen the joints.  Some
stopped pipework I have has a wood screw at the top corners of the
larger pipes (over say, 3' in length) for the same reason.  I think
that this may be a desirable feature.

The thickness of the pipe stock does gradually decrease as the pipes
ascend in pitch.  Typically, they will have the same thickness for say,
six or eight pipes, then will decrease by a small amount, say 1/32" or
so.  For example, the wall thickness of the melody violins might start
out at 7/32" and would gradually decrease to 3/16" or 5/32".

Mr. Chester seems to be pretty well-equipped regarding his equipment.
Lots and lots of clamps speed the work tremendously!  The more one can
afford, the better.  The two-screw "Jorgensen" hand screw clamps are
the best thing going for gluing tapered resonators for reeds, but
they're expensive.

He will need a selection of small chisels, a sharp pocket knife, and
several small flat files (the so-called Swiss pattern) to smooth hard
wood, as well as perhaps an emery board or two.  Feeler gauges will be
needed for accurately cutting the wind ways.  The jointer is not abso-
lutely necessary, but I have found it useful in squaring-up wood that
has gradually become parallelogram-shaped in the planing process.  The
planer cannot correct that.

Personally, I use white or yellow carpenter's glue to make my pipes.
I wouldn't use non-traditional materials on a first-class restoration
of a choice instrument, but since I do only new work, I've used only
new-fangled glues!

Dave Vincent