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POST 3
The Top or Sound Board
is generally considered to have the most impact on how a guitar
sounds. The wood the top is made of, the thickness of the top,
the placing of the bracing, the dimensions of bracing, sculpturing
the braces, grain count,
tap tuning .................; well it gets pretty complicated.
Everything you do to the top will eventually effect the tone
of the guitar.
The
adventure begins when you pick a set of boards for the top.
I have chosen a quarter-sawn bearclaw Sitka Spruce sound board
from Canada. The bearclaw is figure in the wood that is more
for looks rather than having to do with the guitars’ sound.
I have joined and sanded the top (the same method used on
the back in Post 2) to just under 1/8”. The top is slightly
thinner at the perimeter and will be thinned a little as it
is sanded before finishing. I will be bracing the top with
Englemann Spruce. Before the bracing begins, the rosette around
the sound hole is inlayed.
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I
start with a dremel router and a circle cutter using dental
drill bits to cut the inner and outer purfling rings. They have
been test fit in the picture below. If you look closely you
will see the bearclaw figure - it looks like claws have been
drug across the wood. It will show up more dramtically when
finish is applied.
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I
am using two pieces of purfling and a ring of Blue Pau Abalone
for the center ring. After the three rings are cut, a thinned
coat of finish is applied so the glue will not stain the sound
board.
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Then
I inlay the three rings and abalone and glue them. |
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The
sound hole is cut out: |
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The
Rosette is rough sanded and I am ready to start bracing the
top.
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The
interior bracing of the soundboard comes next. The thickness,
height, width, shape and placement of the braces have a great
deal to do with the final sound of the guitar. The builder tries
to control the overall sound of the guitar by combining a top
(of just the right thickness for the wood being used) and braces
of the right dimensions for the top. |
Tap tuning, brace sculpturing and even tuning each brace to
a particularnote are all methods used by luthiers to get a top
with just the right amount of flexibility to produce the sounds
of a great guitar. The following pictures document my method.
I start by
marking the brace pattern on the inside of the soundboard and
glueing the ‘X’ braces to the top.
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The
‘X’ braces are shaped with chisel and sandpaper.
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Each
brace is shaped to the 30’ radius of the concave workboard and
glued to the top.
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Shaping
the brace with a chisel :
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The
finished upper face brace. |
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The
soundboard bracing, shaping and voicing have been completed: |
The
top is now ready to be joined to the sides. I will cover that
in the next Post; number 4. Please email me with any questions
or comments. Thanks for following this build - mdg
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