STEP
5
Adjust the Relief
Once you have your measurements, you’re ready to begin
the process of changing the action.
1. Remove the truss rod
cover at the headstock. (On some flattops, you access the
truss rod through the
soundhole.)
2. Adjust the truss rod.
Turn the wrench
clockwise to tighten
the rod and reduce forward bow, or counter-clockwise to loosen the
rod and reduce back
bow. Go slowly, making very small adjustments and checking
the results each time
you move the rod.
By tightening the
914’s truss rod, I
reduced the relief from
.022" to .015". This is
the proper amount of
relief for Chapman’s
playing style. Any less
relief and the strings
would be likely to
rattle against the frets.
Tip: If you have any
doubts about how to
adjust a truss rod, get
a guitar repair book
or study the manual
that came with your
instrument. Many
manufacturers offer free
online instructions for
adjusting the truss rods
on their guitars.
DIY > ACOUSTIC INTONATION
STEP
6
Carve a New Bridge Saddle
Though it had been played hard for years, Chapman’s guitar
was in great overall condition. But the bridge saddle was worn
and rather than spend time trying to intonate it, I decided to
carve a new one instead. With a new saddle, I could simultaneously address the guitar’s action and intonation problems.
I chose a bone saddle blank because bone sounds great
and is easy to shape with a file. (Important: Saddle slots are
typically either 3/32" or 1/8" wide. Before buying a saddle
blank, you need to measure your guitar to determine which
thickness is required.) To carve the new saddle:
1. Remove the strings and
the old bridge saddle.
2. Measure the fretboard
radius (Photo 3). It’s
very important to
get this right, so you
need to use a precision
radius gauge. A multi-radius tool or sets of
individual radius gauges are available from
such luthier supply
companies as Stewart-MacDonald and
Luthiers Mercantile.
3. Place your old saddle
against the new blank.
Using a mechanical
pencil, trace the contour of the old saddle
onto the new saddle
blank. This will serve
as a basic template for
shaping the replacement saddle.
Note: If your original
saddle was too tall, you’ll
have an opportunity
later to remove the extra
