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It's my religion: all my soundboard braces are strictly selected,
split, and processed to be absolutely as perfect as I can make them. I
spare no effort since my approach requires that the soundboard be
braced with the "minimum adequate structure" and I can't achieve that
with braces cut like salami slices off a randomly sawn
plank. The X-braces have the most stringent requirement because I can
find very little spruce that doesn't twist appreciably in 19 inches. My
starting block (above) has to be from an old tree because the
less curved the annular rings are, the more braces I can get from it
before I have to re-joint it or re-split it square again. My system
wastes a LOT of spruce, and I figure that I toss or sweep up off the
floor about ten to twenty times the stock that I actually use. At left
are the tools I use for splitting.
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I've taken the opportunity to make enough stash for the next six or
seven instruments, about 1/3 of my yearly output.
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Our jointing device uses an upside down plane instead of a spinner cutter head.
The idea is almost exactly like a power jointer but it's made of wood.
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The jointed top gets joined on the joining fixture. Pretty self-evident.
Turning the ebony cams exerts pressure on the soundboard seam.
The hold-downs make sure the thinned-to-dimension plates align properly during gluing.
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I actually like subtly-striped soundboards--the pure white stuff doesn't impress me much.
I guess that makes me quite popular among the woodcutting folks tired of seeing so many beautiful tops
disdained by the perfection-eests.
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Here's where I draft the rosette pattern as a guide for the fly-cutting steps to come.
We've chosen a two-ring scheme. The widths represent the actual widths of each ring's elements.
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I wouldn't trade my trusty-- and massive--www Sear Craftsman fly-cutter
for any of the other flimsy deals out there.
I've had a precision machinist make me a set of cutters for .050, .085, .10, .125, and .25
slots out of high-speed steel lathe bits.
They have served me well for two dozen years without resharpening,
although I do touch them up periodically by hand on a diamond stone.
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I aim for a snug wobble free fit, taking into account that the glue itself
takes up a bit of room also. If the slot has a wobble fit
I'll have a lot of tedious dropping-in of lacquer during the finishing steps.
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After inserting the inner abalone ring, and leveling all,
THEN I cut out the sound hole. If I cut out the soundhole before leveling,
the soundhole edge gets beat up during the leveling steps.
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After the soundhole is cut out, the undersurface of the top gets drafted
for all the braces and patches. The first step in bracing the top is to
prepare and affix the flat elements. The curved braces go on last.
First, a .10" rosewood bridge patch, trimmed to fit under the bridge
and between the lower arms of the X brace, is glued down flat.
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The upper transversal graft, the soundhole braces and the fans go next.
The fans and braces are carved to a peak, the soundhole braces are trimmed
back so they can butt securely against the major curved braces;
the fans are feathered down to the top. One arm of the X-brace blank is seen
placed against the soundhole brace and the bridge patch.
It will be notched accurately with it's mate in a lap joint that crosses
between the bridge patch and the soundhole.
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The x-brace blank has been notched accurately and joined in a lap joint,
so it tightly abuts the SHB's (soundhole braces) and the bridge patch.
The bottom edge of both arms will be trimmed and sanded into a gentle fair curve
before the x brace blank is finally glued to the top. It is not glued down flat
against the workboard, it will be glued to flexible slats so the soundboard can
wrap around the curved x braces, imparting a gentle dome to it after the glue sets.
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No scalloping in my technique. Instead the X's are planed to 1/8 at the ends,
and into a gently curved configuration dropping evenly from the apex as shown.
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Another good reason for taking the time to select the brace material. Carving is a breeze.
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Finally the upper transversal face brace is arched precisely
lest the fingerboard end not sit on the soundboard in line with the portion
that sits on the neck shaft--and then it's glued down to the soundboard as shown.
If the arch is improper, when the guitar is completed and strung up,
the fingerboard end will either dive or worse, climb, and interfere with the action.
The correct amount of that arch varies according to the scale length and width of the upper bout
of the guitar, and is derived from the lessons learned from hard experience.
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