Transcript Building The FIDELCO Ukelele

Building The FIDELCO Ukulele
Specifications: Solid Mahogany Soprano Ukulele, 13.5” Scale Rosewood Fingerboard
with Mother of Pearl Diamond Inlay, Black/Ivoroid/Black Rosette, Rosewood Bridge,
Reclaimed Corian Nut, Rosewood Headstock Veneer with Mother of Pearl Logo and
Shepherd Inlay,
The Top and Back
The entire uke is
constructed from
reclaimed mahogany from
a local plaque
manufacturer. At one
time, these plaques were
being cut up and sold for
firewood. One plaque will
yield three top and back
plates. The plaques are
ripped down the center
then resawn on a bandsaw
so that they can be
bookmatched. The edge is
planed and the halves are
glued together. After
drying, they are ran
through a thickness sander
which reduces them to
.080 of an inch. A much
better use than fuel to
roast a wiener.
The two pieces of wood are scrutinized to determine their best use. Ideally, the grain on the tops should run on the
quarter, meaning that the grain is perpendicular to the top, which adds stiffness to counter the tension from the
strings. Using a plexiglass template, the shape is traced onto the top and back paying special attention to match the
template centerline with the joint that runs down the center of the plate. Once traced, its back over to the bandsaw
where the plates are rough cut to shape.
The center of the soundhole is located on the top and then goes to the drill press where the channel for the
rosette and the hole itself is cut using a circle bit.
The soundhole isn’t cut completely out on the drill press but just deep enough that it can be finished with
a sharp knife. This reduces the risk of tearout around the soundhole. The channel for the rosette is
.050 of an inch deep but once installed, it will provide further reinforcement to the soundhole.
Once the channel is cut and the soundhole is cleaned up, it’s time to install the rosette. The rosette is made up
of a piece of ivoroid that is .050” thick surrounded with two pieces of black binding that are .020 inches thick.
The trick is to get all three pieces pressed into the channel at the same time. They strips are fitted and the ends
are trimmed then re-fitted and trimmed again and again and again until they are perfect. Sometimes it takes 15
minutes and other times an hour. Luckily, I only had to start over once on this one and it took about twenty
minutes.
Finally, the glue dries and the rosette can be scraped flush with the top.
The bracing
location is
mapped out on
both the top and
back plates. The
bracing provides
support as well as
a degree of mass
that affects the
final tone.
Instruments with
stiff, or heavy
braces, tend to
sound a bit thinner
and tinny whereas
a lighter setup will
give it a nice tonal
balance across the
strings. Too light
and the top will
sink.
Here is a close-up of the braces. They are carved using a chisel and finger plane so they resemble a pyramid
with a slightly rounded peak. They are then tapered on the ends. The kerfing and sides of the uke will be
notched so that they are tied directly into the sides of the instrument.
All the braces are installed plus the rosewood bridge plate that sits underneath the bridge and supports the shear
tension from the bridge, as well as helps spreads the vibrations of the top to the sound chamber. They will be set
aside while work on the body begins.
The Body
The sides are bent in a mold using a
silicone heat blanket. Before going into
the mold, the book matched sides are
taped together, wetted and wrapped in
foil.
The blanket heats the wet
sides which creates steam
and makes them pliable to
mold them to the shape in
the bending jig.
A heat blanket is put on top of the
sides then they are sandwiched
between two pieces of stainless
spring steel. Along with holding the
sides to the shape of the mold, the
steel also helps distribute an even
heat.
As the sides become pliable from the heat, the waist
is clamped down using the handle attached to the
large steel pipe at the top of the bending jig. Slowly,
each side is pulled down and hooked to a spring that
runs under the jig that will maintain tension on the
sides and hold them to the mold. The sides are heated
and cooled several times to “set” them to the final
shape.
So, here they are. As you can
see, they are perfectly matched
sets.
They will be trimmed to length then put into a mold where they
are glued, tapered, kerfed and the tops and backs attached to
create the sound box.
The sides are put into a female mold so that they will maintain their shape while further work is
done.
Traditionally, the ukulele has a tapered back. The sides at the
neck block is 1 13/16” then increases to 2 1/8” at the tail block.
The taper is achieved by angling
the body in the jig then cutting it
with a fine kerf saw.
There are two more things to do before gluing the top and back on to complete the sound box. First,
the neck block, which will be the point where the neck joins the body, and the tail block need to be
installed. They are sanded to match the rounded profile of the body, glue is applied and they are
clamped on the centerline.
Next, the kerfing, or lining, is installed around the edges of the sides. This provides support as well as
gives a larger surface area for which to glue the top and back plates. The kerfing is notched so that it
can follow the curves of the instrument. Below, the mold is sitting on a piece of sandpaper that is glued
to a smooth piece of marble. Before, and after, the kerfing is installed the sides are sanded level and
square by rubbing them over the paper while in the mold. Once all the kerfing is installed it will be
time to glue on the top and back plates.
Normally, I use spindle clamps when gluing up an instrument, but since a uke is so small I find this a much
easier and quicker method.
Once the glue is dried then the edges are
routed flush with the sides to prepare it for
binding.
This instrument will be “side” bound using
rosewood with a white/black/white accent strip.
Its called side binding because the accent
appears on the side of the instrument versus the
face.
First, a channel must be routed around the top
and back that is the width and depth of the
binding. When routing the binding channel, you
remove so much side material that you reveal
the kerfing.
Since the binding is wood, it is bent to
shape using the same method as the
sides. It is trimmed and glued into the
channel. Tape is used to “clamp” it into
place while the glue dries.
Since this was a special commission, I decided to incorporate the side binding effect in the tailpiece
strip. It took several attempts at this to get the miters matched up but I think it is well worth it.
Finally, we have a sound box and we can start
building the neck.