STEP
7
Adjust the Saddle Height
With the top of the saddle sanded to match the fretboard radius, it’s time to fine-tune the action.
1. Put the old strings back
on, tune them to concert
pitch, and measure the
action. At the 12th fret,
my target is to have the
action measure 4/64" for
the 1st string and 5/64"
for the 6th string. If you
use the correct radius
block to shape the top
of the saddle, the strings
will consistently graduate
in height from the 1st to
the 6th string.
2. If the action is too
high, loosen the strings,
remove them from the
bridge, and gently pry
out the saddle. Using a
mechanical pencil, mark
a straight line along the
bottom of the saddle corresponding to the height
you want to remove.
Carefully sand off this
amount from the bottom
of the saddle (Photo 9).
On Chapman’s 914,
the action was about
1/64" too high when
I first strung it up.
Following the procedure
above, I sanded off that
amount from the bottom
of the saddle. Finally,
I got the height right
where I wanted it.
Tip: When sanding off
material from the bottom
of the saddle blank, use
straight strokes and move
in only one direction. It’s
easier to keep the bottom
of the saddle flat—which
is what you want for the
best sonic transfer—when
you sand in one direction.
9
Lower the saddle height by sanding from the bottom of the blank—not
the radiused top. Here I’m using 80-grit sandpaper attached to a flat
wood block. To keep the bottom flat and square, I apply even pressure
across the entire saddle.
STEP
8
Check String Height at the Nut
There was one more issue to resolve before I could finish the
new saddle for this 914. The action at the 1st fret was still a
little too high, so I needed to re-cut the string slots to correct
this. Here’s the process:
1. Using gauged nut slotting files (one for each
string), cut each string
slot to the proper depth.
Begin with the 1st string,
which should measure
1/64" above the 1st fret.
2. Continue to measure and,
if necessary, cut the nut
slots for strings 2-6. Each
string gradually increases
in height from the 1st to
the 6th, which should sit
2/64" above the 1st fret.
STEP
9
Compensate the New Saddle
Intonating a guitar involves adjusting the length of each string
so it will play in tune along the entire fretboard. Conceptually,
it’s simple, but the process can be complicated—particularly
on a flattop that doesn’t have individually adjustable saddles.
Before we begin carving the saddle to subtly adjust the vibrating length of each string, it’s good to step back and look at all
the elements that affect a guitar’s intonation.
The location and condition of the string nut, frets, and bridge
saddle each play a role. For example, if the nut is too far or too
close to the first fret, the guitar will never intonate properly. Also,
if the string slots in the nut are worn, this will also prevent accurate intonation. This is why it’s a good idea to check the slots and
make sure the nut doesn’t need to be replaced.
Frets also play a big part. When the frets begin to wear,
they flatten out and change their point of contact with the
strings, and this also affects the intonation along the fretboard.
Recently, I had a guitar on my bench that had heavy wear on
the first five frets. When I checked the intonation, those were
the only notes that were out of tune. So if your guitar isn’t
playing in tune, it could be some frets causing the problem.
Sometimes I come across a bridge saddle slot that’s in the
wrong location on the bridge. When that’s the case, even after
compensating the saddle, the strings still fret too sharp or too
flat. In this case, you have to relocate the saddle or fill the old
slot and route a new one.
Relocating the nut or saddle, or doing fretwork is beyond
the scope of this article. However, if you have a guitar that’s
built correctly—like Chapman’s Taylor 914—all you need to
do now is carve the intonation points on the bridge saddle.
This is called “compensating” the saddle.
Essentially, instead of having all the strings cross over the
top of the saddle at its center, you’re going to create a unique
resting point for each string. Some of these points will be
closer to the soundhole, others closer to the bridge pins.
Here’s how I do it:
1. Mask the bridge area
around the saddle
with strips of low-tack
blue painter’s tape.
This will shield the
wood from any slip-ups
from your file.
2. With a mechanical
pencil, mark a line as
described below to indicate where each string
will cross the top of the
saddle. This line will
guide you as you file
(Photo 10).
For the high-E string,
place the line halfway
across the saddle. For
the B string, mark a
line almost at the rear
(pin side) edge of the
saddle (Photo 11). The
G string has its contact
point close to the front
(soundhole) edge of the
saddle, so make its mark
there. For the low E,
mark a line 1/32" from
the rear edge. The A and
D contact points form
a diagonal line between
the low E and G contact
points (Photo 12). The
D will be just a bit back
from the G, and the A
will sit slightly forward
from the low-E string.
