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12 string
This started out one day in about 1981 when a plank sticking out of the dumpster where I lived caught my eye. There were two discarded table leaves of very nice walnut. Judging by the tool marks on the back, these were hand made into a table sometime in the mid to late 1800s. I decided to build a guitar. The one at right is the remaining table leaf, destined to become another guitar someday. walnut table leaf
Mark Spoelstra Folkways record number 2444

Inspired by a Mark Spoelstra record I swiped out of my big brother's collection when I was a teenager, I wanted a 12 string. I'd borrowed my brother's Stella 12 string when I was young, and later owned a nice Guild, but had been without one for years.

I have strong opinions about the 12 string: I think of it as a picking instrument, not so much a strumming instrument, and it's not meant to be tuned to E like a regular guitar, but more like D or lower, to bring out a resonant baritone sound. The addition of six more treble strings requires building for more bass, with a big body and sound board.

     
side in the mold At the time I was working long hours, and didnt have a lot of money, so I envisioned a simple traditional look. I made a pretty good start, getting the sides bent, the neck shaped, and a start on the sound board. I had nothing but hand tools to work with, but the woodworking skills I picked up in the boat yard stood me in good stead.

Both book-matched sides, and the book-matched back pieces were hand sawn from a single 1" thickness with an ordinary carpenter's rip-tooth hand saw, which I'd hand sharpened and set myself.

The neck was laminated from the rest of the same piece. It was a rookie mistake to fully shape the neck at this early stage, but more about that later.

sound board

By 1983, work, travel, family, life, jobs and career all combined to put the project on the shelf where it sat for nearly thirty years. It's somehow survived nine moves that I can count, including halfway across the country.

Along about 2009 I found a renewed interest in music and the guitar. I wanted a 12 string, and in November 2011 I decided that dammit, I was going to finish it!

     

The first thing I got to work on was the neck.  Most luthiers carve the heel, where it attaches to the body, and peg head, leaving a rectangular section through most of the length.  This makes it easier to clamp in a vise, even after attaching to the body, and is carved off as one of the last steps in building.  So here I had to get creative in order to hold onto it while routing the channel for the tension rod.

Routing the channel for the truss rod

Although I'd originally envisioned a simple design, I had to put something on the peg head. I bought Larry Robinson's book The Art of Inlay, to gain both confidence and inspiration. Commercial guitars usually have the brand name, but I opted for this white bison. It's made of salvaged ivory I obtained from Joe Wood, a local piano rebuilder. I based the artwork mostly on frame 1 of the Muybridge Buffalo sequence, with some changes.

Bison inlay Bison inlay in peg head

Several copies of the drawing are made, and glued to the ivory, so the pieces can be cut out with a fine saw. Then they're glued together on a piece of wax paper. After the recess is routed out with a Dremel tool, the complete inlay is glued in place and leveled off with sandpaper.

Once I had my first inlay under my belt, I couldn't resist a few more. I've always liked big position blocks for their visual effect. I mostly play without looking, but sometimes I take a quick look, and then I want to see the fret board clearly. This design adds an additional visual element, in that the position markers wrap around to the edge, so I don't have to look at the front.

All ivory used in this project is what's called estate ivory, brought into this country before any bans or restrictions were in place. It is legal to own, but this guitar can never cross US borders, in or out. A newer source of legal ivory is fossilized mammoth tusk, which although somewhat more expensive, has a lovely antique look, and carries no restrictions.

Routing out for the position blocks in the finger board Gluing the ivory position blocks
Neck and fret boardNeck and fret board
Above, the fret board isn't glued on yet. I used a drill template to put in a pair of small hardwood dowels, so that I could finish the fret board and neck together. The fret board doesn't get glued on until after the frets are installed and the guitar body is fully assembled.
Neck and top bracing glued to sound board
What I'd started back in the early 80s locked me in to certain construction methods and designs. Back then there were no plans available for 12 string guitars. This design is a composite of a few books I had back then, and study of some guitars I'd owned or played in music stores. I'd decided on a "Spanish foot" neck design, where the one-piece neck has slots that the sides (sometimes called ribs) go into. In this case though, I innovated a new variation on it, reducing the thickness of the "foot" that contacts the back, and extending the face of it out under the fingerboard all the way to a shallow mortise in the first brace above the sound hole.
Sides and side bracing
The sides are already bent. Triangular linings are bent and fitted to the sides, so that the sound board and back have something to glue to. To allow the lining to bend, most luthiers make a series of cuts most of the way though the triangular section, 3/8- to 1/2 inch apart, called kerfing, but I went the extra mile with steam bent linings. My rationale was that it would allow fewer nooks and crannies for dust and moisture to accumulate, and perhaps present a better acoustic profile.
sides with bent linings and side bracing

 

Then there was the problem of the screw holes in the back:

Screw holes in the back Cutting out the ivory on the bandsaw Glued together with epoxy
I'd originally planned to join the two back plates so that these holes fell outside the cutting line near the waist, but then I read that it's best to join the densest most vertical grain at the center. In Larry Robinson's book, from which I'd learned to inlay the buffalo, he describes how he got into inlay: One day in the luthierie, he accidently drilled a hole in the back of a guitar. The boss said "that's OK, just put an inlay in it, and we'll charge extra." Thus a career was started. So, I joined the back as it should be, and inlaid some little buffalo tracks where the screw holes were.

Inlaid ivory buffalo tracks

 

After the back braces are shaped and glued in place, the back is ready to go on.

Last look inside before gluing the back

 

Using special router attachments, the front and back edges are prepared for banding and purfling, in this case ebony and maple, which seal the edge and end grain, and protect the edge. They are pre-bent using a hot bending iron, and glued in place with a long rubber band made from a heavy duty inner tube.

Router attachment   Edge prepared for banding   Banding is glued in place using a long rubber band, in this case made from a heavy duty intter tube.
The edges are now scraped level, and final sanding is done. The frets have been installed in the fret board, and finally this is glued on.
Finally sanding is done

The next step is to mask off the spruce top, and work grain filler into the pores. This is sanded off when dry.
Grain filler
When lacquer is first sprayed on, it has a slight orange peel surface. After ten or more coats, it is left to cure for anywhere from one to four weeks, depending on the product used.
Spraying lacquer Raw lacquer surface
After curing, the finish is wet sanded with successively finer grades of sandpaper to about #1500 or 2000, then rubbed to a glossy finish with a series of rubbing compounds.
Finished guitar

In theory, if a guitar is fretted half way between the string ends, it produces an octave. But due to the string's stretch as it is fretted, which is different for each diameter, the distance to the bridge saddle needs to be compensated, or intonated. Usually, the bridge is glued on, and the guitar strung up normally, and the recesses for the ivory bridge saddle cut afterwards. In this case I knew it could get complicated for a 12 string, so I rigged a simple temporary tailpiece. The bridge is still not glued on, but is precisely located with a pair of blind dowels. With the strings at playing pitch, I simulated the bridge points by sticking a Q-tip under the strings. Moving it back and forth, I checked each string with an electronic tuner. With these points measured and laid out, it was clear, three saddle pieces would be needed.
Temporary tail piece

I took the bridge and the tail piece off, and made the grooves for the ivory saddle pieces on a CNC milling machine, then glued the bridge in place.  The bridge pin holes can now be drilled through the top, and reamed to the proper taper to receive the bridge pins.

Completed bridge Bridge saddle detail

I wasn't planning to play it, but I suddenly realized that, with the Q-tip in place, I could! My wife came downstairs just as I was finishing tuning, and took this photo of the first music it ever played. In this picture, measured from the time I finished tuning for the very first time, after more than thirty years, the guitar is less than one minute old. Can you tell I was happy?

Click here, or on the photo below for the finished pictures

The first music
     


Grateful acknowledgement to Robbie O'Brien and his group of luthiers and students; to several other luthiers, and the tech support people at Stewart MacDonald and Luthier's Mercantile who answered questions; to my brother who got me started playing when I was about eleven; and to my wife, who supported me in this and all things.

This isn't the end of story. This was my first guitar. I have much of the wood now for several more guitars. After catching up on a few projects around the house, and building a tree house for my grand kids, I have three more started.

 

Here's a little clip: You Tube link
     
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