|Building my 2nd
Acoustic Guitar - Page 4
June 3, 2008 continued
Then I began to turn my attention to the neck. Paul Lloret, bless his heart, gave me a neck blank with the
scarf joint already done, so I started by laminating on the pices for the heel and cutting the channel for the
truss rod. I did the channel on the tablesaw, being careful to stop the cut just where I wanted the
peghead-end of the truss rod to be. I't's very important that the truss rod should fit as snugly as possible
without having to force it in. So I very carefully snuck up on it, trying out each tablesaw adjustment on a
scrap pice first before doing it on the neck. I squared and deepened the peghead end with chisels. This
truss rod, a 'Hot Rod' from Stew-Mac will, obviously, be adjustable from the heel.
A truss rod, by the way, resists the pressure of the strings to bend the neck, and an adjustable truss rod
(like this one, and most you can buy)can be tightened or loosened to counteract the pressure if a bend
Here's a little closer shot of the end of the truss rod channel. Blurry, but you can see a couple of
things. First, the truss rod will not project past the neck tenon into the neck block -- this is so
the neck can be removed if necessary... not to mention assembled in the first place! Next, the
adjusting nut is a bit larger diameter than the rest of the truss rod and so a hole needs to be drilled
to accommodate it. I followed the truss rod instructions' suggestion of clamping a peice of scrap
in the slot to give me somewhere to center the drill bit.
So then I started preparing the body for the bindings, starting with the back. As you can see from this
picture I built a little ramp on my router table to allow for the curvature of the top and back. I clamped
on a scrap piece shaped to be a stop so that the width of the cut can be set. Of course the depth is set
by raising or lowering the router itself.
Here I have completed the first cut (I will need to make another for the purfling). Here you can see the
maple 'wedge' that disguises/replaces the butt joint of the sides. Cut out the space for the wedge with
the sides of the space straight, then cut the wedge itself a bit oversize and bevel its edges slightly. This
will ensure no gaps when it is glued it.. just plane/scrape/sand it level.
Then I lowered the router a bit and pushed back the stop to create a shallower, wider cut to make the
ledge for the purfling (in this case, a simple black/white/black strip). Make sure to test the dimensions
of your ledges on scrap wood using the actual binding and purfling you will before committing your
guitar to the router! Don't rely on measurements alone...
So here's the back/side join, double-ledged, ready for binding. I did have to clean it up just a bit with a
chisel, but you pretty much always do.
June 8, 2008
Some work done this week: Bent bindings for the back, applied and trimmed bindings for
back, layed out fret slots. I'll put up a picture of bending the binding when I do the top
bindings, but it's essentially just like bending the sides, just with a thin little strip of maple.
The ledges were already prepped (described above), so I just had to glue the binding and
purfling strip into place. There are several different ways to hold the binding in place as
the glue dries, including elaborate 'binding the binding' setups with stretchable cord, but I
prefer the straightforward method of taping. There is special tape for this job, like heavy
masking tape but stronger and with a stronger (yet clean-removing) tack.
I cut my own maple binding strips by the way. It's easy to do on the tablesaw. I cut them a bit
oversize just to be sure, so I have to scrape the 'top' of the binding flush with (in this case) the guitar's
back and then use a flush trim router bit on my router table to trim the bindings (mostly) flush with the
sides. Inevitably some scraping is needed even if you use a router. In this picture I'm working on the
top of the binding. I put tape on the corners of the scraper to avoid unfortunate scratches on the back
(which I only thought of just now while doing this--duh). I have just now noticed the purfling is
obscured in these pictures, but it's a fine-line black/white/black on the guitar's back, which makes a
nice transition from the maple binding to the mahogany. I'll do a closeup later.
Then I laid out my fretboard, marking the fret positions based on the 25 1/2" scale in the plan I'm
using. The plan conveniently includes slot positions, measured from the nut, in thousandths of an
inch. Fortunately I have a dial caliper that measures exactly that so it was just a matter of being
careful and checking each measurement twice but no problem. You can't see the scribed fret
positions in this photo but they're there. A still life of what you need to lay out a fretboard (you don't
really need the computer):
June 16, 2008
I continued work on the body by cutting the ledges for the top binding/purfling and starting to
bend the binding/purfling for the top. For the back pufling, I used a narrow black/white/black
made of fiber. It was thin enough that I didn't need to pre-bend it (the purfling); it bent around
the sides very nicely, held in place by the maple binding. On the top I'm using a bolder B/W/B/W
purfling with more wood in it, so it will have to be bent along with the binding. Here I'm just over
halfway done with that task:
One side's binding/purflig is bent; the other side is just getting started. I use the body outline on the
plan for a general guide, but I frequently check the fit on the guitar to be sure. Ideally you want to
bend the binding/purfling so that it's a little outside the actual curve (except for the waist). It's much
better to pull it in around the curve than to have to be pushing in a section that has too much curve.
Also, as with bending the sides, your mantra must be SLOWLY. An unquiet mind leads to haste and
you'll break it for sure (much easier to break binding than a side, and much easier to break purfling
than binding). With solid wood binding, like a side, you can feel the point at which the wood goes
plastic and takes the bend, but with purfling for some reason I can't feel that point and just have to go
very very slowly and use very little pressure.
June 21, 2008
Then I did the binding on the top, just as on the back. Route the channels for the binding and
purfle, glue and tape. I did have one problem with the top. After I had done the second half of the
binding (I do one half at a time to keep the stress level down, with a miter joint where the halves
meet) and the glue was dry, I found that I had not pressed hard enough at one point and left a
sizeable gap between the purfling and the top, so I had to redo a section. Un-glued the
binding/purfling with water and a hot iron, reglued and retaped it and now we're ok. Here I'm
scraping the top binding level with the spruce top.
Then, as with the binding on the back, I trimmed it flush with the sides using a flush trim bit on my
Immediately after taking this picture, though, I thought better and used the ramp (as in the first photo on
this page but with this bit and without the overhanging stop), which supports the side better and makes it
less likely that I'll tilt the body and make a little dip in the binding.