This article does not explain the layout and geometry of segmented bowls, about
which there are other articles and books. Instead, it explains a method for
making segmented bowls with nonlinear, ornamental inlays. The methods explained
here may be neither original nor the best; however, I enjoyed figuring them
out myself and offer them to you for use and/or improvement. If you are one
of those persons who just can't wait to crank a piece of wood into a lathe and
start turning, this technique may not be for you because most of the work is
in the preparation of bowl inlays and segments.
Segmented bowls are typically made up of rings of glued-up wedges, as
illustrated in the picture to the right. Makers of more ornate bowls vary
the wood and patterns of the wedges to create non-curved designs in the
side of the bowl. Many of these ornate designs would remind you of Navaho
My interest in segmented bowls came as a result of the love of turning
and the desire to do something useful with wood scraps. Since many of
these scraps are small, I more often turn out smaller, 8-sided bowls whose
wedges are cut at an angle of 22.5 degrees. Angle accuracy is important
so I cut templates using an Incra Miter Gauge and use these templates
to set saw and sander angles.
|Not wishing to spend inordinate amounts of time hand-cutting and fitting
inlays into wedges, I devised a router table/shaper jig that allows you
to safely rout/shape small pieces with a high degree of accuracy and repeatability.
This jig, shown to the right, accepts 1/4 in. thick template inserts that
ride against a top-bearing 1/2 inch router bit. The purpose of the jig is
to(very) firmly hold small work pieces of various sizes on top of the template.
Each design requires a male and female template, which is made by drawing
your design on a piece of paper, attaching the paper to a piece of wood
(that fits perfectly into the jig's template cut-out) using, say, 3M Super
77 spray adhesive and then cutting out the curve with a jigsaw or coping
saw. If necessary, trim up the templates so they have perfect male/female
The trick to inlaying (elongated) wedges to create two identical halves,
glue them together and put the 22.5 degree bevel on each side. It is important
that all pieces be uniform in length and square lest things get out of
kilter on the glue-up.
Using the jig and a router table or shaper, cut 16 (for an 8-sided bowl
ring) identical pieces consisting of half a wedge segment piece and half
of an inlay. Glue the two together and put into a vise or clamp to get
them to seamlessly mate. When mated, the inlay piece (which is darker
in the illustration to the right) will have excess that must be trimmed
off before the two halves of the wedge-to-be can be joined.
Once the male/female pieces are (tightly) joined, it will probably be
necessary to clean up the face of each wedge half before joining to the
other half. I prefer to use a disc sander to do this but you must take
care to keep the face your sanding parallel with other face if things
are to fit together later on. I've gotten to the point where I can freehand
the sanding but clamping a scrap perpendicular to the disc to use as a
guide is a good idea when starting out. It is also important that the
table be square with the sanding disc. Sanding can also be done by hand
using sandpaper on a flat surface such as a sheet of glass or saw table
|Once the 16 halves are joined into 8 wedges-to-be and glued up, it is
necessary to bevel each side to the required angle (e.g., 22.5 degrees for
8 sides). I've found the safest and easiest way to do this is with either
a cutoff sled or a sliding saw/shaper jig, such as the Delta model shown
in the picture to the right. Note that the right-most hold-down has been
moved off of the wedge piece for illustrative purposes. It is important
that the small piece be fimly held parallel to the saw blade. The left hold-down
is used to secure a miniature sled that rides on the jig. As previously
stated, I use a template cut with an accurate (Incra) miter gauge to set
the blade tilt to the proper angle.
|When all eight elongated wedges have been beveled, I glue them up two
at a time by hand. What seems easiest is to vigorously rub glue into the
two bevel faces so there's little or no excess that will squeeze out and
then press the two together by hand and hold tight for several seconds.
Having no excess glue in the joint gives you a quick set. Be sure to glue
them up so the inlay runs the same way in all pieces. More than once I've
stupidly mismatched the patterns by not paying attention during this step
in the process.
|Glue up the wedges into two bowl halves and don't go any further until
you first sand the faces of each half flat. Regardless of the precision
of your bevels, you probably won't get a perfect without this step. Then
glue the two halves together in the same manner as described above. I used
to use band clamps to hold the two halves together but careful fitment and
glue application (rub it in with little or no excess) makes this unnecessary.
Once the glue is dry, the piece can be put into the lathe chuck.
|The next step is to chuck up the piece and clean up one end to accept
a sacrificial bottom piece that becomes both the bottom insert and the piece
that holds the bowl in the chuck for final turning. Make sure the insert
doesn't fit either too loose or so tight as to not seat well once glue is
applied. When dry, the piece can be turned around and put in the chuck the
other way for turning, sanding, burnishing and finishing. This is the fun