Binding, Purfling, Inlay, and Veneer
Top of tutorial
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The end-graft is cut into the butt end of the guitar as the first step in the binding sequence.
It's a wedge of material that matches the binding (my choice, it seems to "frame" the side plates).
I used to use a homemade fixture that clamped onto the end of the guitar which provided a platform
for a router, with a slot down the middle, and two fences which guided the router base across the
back to cut a perfect wedge-shaped void. But the fixture broke while using it and ruined a
brazilian rosewood guitar soundbox. So now I just repeatedly score two tapering lines across the
side plates with an x-acto blade, and chisel out the material in between. it's safe and just as quick
as setting up an elaborate fixture and a router. Sometimes simpler is better.
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Note the way the soundbox is held to the table: four padded cam clamps on the guitar,
and a metal bar clamp to clamp the cam clamps to the table. The inlayed wedge is tapped in
with glue to tighten it in it's mortise, and a body clamp holds everything down tight for good measure.
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My Rockwell 3/4 hp. router with the 100B base and a adjustable laminate cutter attachment affords
an accurate rout around the top for the binding strip. I've had the router rebuilt by Rockwell
three times since I first bought it in 1969. Recently, it finally gave up the ghost in a
non-rebuildable way, so I broke down and bought a new one. It only cost 3 times more than it did in 1969.
But this time, the adjustable laminate cutter attachment was no longer available.
So I had to graft the old attachment onto the new router base.
Anybody know where to get these attachments any more? I've been asked 1000 times where to get
the attachment pictured in the book, and all I can do is shrug my shoulders...
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The back rout is much more difficult. Due to the contours of the back, the router cuts a mortise
of uneven depth. It must be followed with a marking gauge to determine the true depth all around
the soundbox perimeter and trimmed back to the marks with a chisel by hand. Very laborious.
Several elaborate back-routing jigs and fixtures exist, each with their own special dangers
and shortcomings. So I stick with the simplest solution: hand tools.
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The top gets purfled with "rope" (also known as "half-herringbone").
I used to purchase these strips made of dyed wood, but in recent years have gravitated to compressed
fiber strips--as supplied by my old teacher, Michael Gurian, to the trade.
They're far more flexible and virtually unbreakable, but require an especially sharp scraper
to level--they're actually harder than wood. As you see I have to prebend the strips:
they have been taped together to form a band and just placed on the side-bending mold and bent
as if they were a side. The charred tape is then peeled off and all the individual strips emerge
with the perfect contour. The purflings are usually all perfect, but I have to bend extra bindings
because several usually break in the process.
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The binding and purfling strips are glued into the binding mortises, and taped tightly into place.
My book describes the process. If the bindings and purflings are accurately bent, you need only one
strip of tape. If not, you have to double up on the tape to coax them tightly into the mortise.
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The entire top has been bound.
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...and then the back. No back purfling on this design.
The outstanding figure on the koa back plate needs no further "beautification".
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Thus the bindings are scraped flush and clean. That scraper blade started off about 3" tall 15 years ago.
After a half a career of sharpening, its down to almost a sliver.
...nice and flexible though...
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