When a customer recently
brought a ’74 Gibson
flattop into our shop for
evaluation, I determined that
its rosewood bridge should
be replaced. The strings were
sloping over a bottomed-out
plastic saddle, and I could
hear that the strings were
getting slightly choked off
because the action was too
low. Additionally, I was concerned
that the wafer-thin
bridge would develop cracks
between each bridge-pin
hole—and also possibly bust
out at the front. I felt a new
bridge and saddle would
improve the guitar both sonically
and structurally.
Last month, we looked at
the first phase of this operation
and discussed the tools, materials,
and procedures required
for the job. (If you missed the
first installment, you’ll find it
in the
PG July issue
here.) This time around,
we’ll look at what it takes to
complete the project.
Bridge Installation.
Before gluing in the replacement
bridge, it’s important to
clean the wood and remove
the oils, dyes, and any other
substances that could bleed
into the glue from the gluing
surface and get absorbed
into the finish. I did so using
acetone, Scott Xtreme Rags,
and a good pair of protective
gloves. I repeatedly wiped the
bridge with acetone until the
cloth came away from the
wood clean.
For gluing and securing the
bridge to the top, I used several
specialized guitar tools from
stewmac.com: a bridge-clamping
caul (item #4600), two
Ibex bridge clamps (#0682),
as well as a bridge plate caul
I cut out from 1/4" plywood
and wrapped in wax paper.
Saddle Location and
Routing. Once the glue had
cured, I removed the clamps,
chamfered the bridge-pin
holes with the bridge-pinhole
chamfer tool (#0459),
and seated the pins using
a 3-degree bridge-pin-hole
reamer (#3227).
My plan was to route the
saddle slot into the bridge
after it was glued to the guitar
top. This way, I could be sure
the saddle would be optimally
positioned for accurate
intonation. For starters, I used
the Saddlematic (#4462), a
tool that quickly and accurately
finds the correct location
for an acoustic guitar saddle
slot. I like to finalize the intonation
with the Intonator,
(#5245), another innovative
tool designed by Dan Erlewine
that lets you dial in the exact
position of the saddle route
and allow room for compensating
the saddle later on.
For cutting the slot, I used a
saddle-routing jig (#4043), a
precision router base (#5260),
and a Dremel rotary tool
(#0358) with a 3/32" diameter
carbide bit (#5153).
A pair of camless clamps
with a 4 1/2" throat (#3708)
worked well to hold the saddle
routing jig in place as I moved
the Dremel base plate along
the jig’s guide plate. Before
restringing the guitar and
trying out the new bridge,
I finalized the unbleached
saddle and seated the strings
properly using a set of bridge-pin-hole slotting saws and
files (#5813).
All these tools help me
work efficiently and achieve a
high standard of quality craftsmanship.
Whether you do
professional repairs or pursue
luthiery as a hobby, the right
equipment is crucial to achieving
superior results. It’s always
satisfying to get a guitar ready
to make sweet music!
John Brown is the
inventor of the Fretted/Less
bass. He owns and operates
Brown’s Guitar Factory,
a guitar manufacturing,
repair, and restoration facility
staffed by a team of talented
luthiers. His guitar-tool and accessory designs
are used by builders all over the world. Visit
brownsguitarfactory.com or email John at
info@brownsguitarfactory.com.