Before I begin to build a guitar the possibilities are limtless. Every step along the way I make decisions which guide the final result in the direction of my imagination, and each step limits the possible outcomes further and further until only one remains — the finished instrument. Even then, because of the ineffable qualities of wood, we luthiers are in the business of attempting to control the uncontrollable. Yet with experience, care, the courage to dream, and belief in one’s self, something special can happen. I put everything I have into each guitar, then go on to the next with the conviction that I can go even further next time. Famed luthier José Romanillos put it this way: “Every guitar of mine is going to be a masterpiece until I put the strings on.”
My method, which I outline here, is uniquely mine, and embodies influences large and small that have affected me over the years. Among luthiers I count Romanillos and John Gilbert as important early influences. But I have been as a sponge in soaking up information and ideas over the years from many other luthiers and especially from players, without whom the luthier does not exist.
I use the basic tools you might find in any wood shop, and a number of specialized tools and jigs designed to complete tasks unique to lutherie. Every luthier finds his own balance between the use of power tools and hand tools. Mine is somewhere toward the middle of the range of possibilities. Most of the tasks of roughing out the parts I do with band saw, planer, and table saw. Power tools prove their worth in performing repetitive tasks. When I make neck blanks or bridge blanks or fingerboards I may make two dozen or more at a time. Conversely, hand tools afford a direct sensate connection to the wood, which is essential, for instance, when working the soundboard. Furthermore, using power tools to make one or two of a part is not very productive because most of the time is spent setting up the tools. Here, hand tools hold their own, unless you have the luxury of a large shop with permanent stations with power tools for each step in the process. But then you have a factory…
I begin with the soundboard. Several times a year I go through my supply of rough cut sets – feeling, listening, looking – conjuring up the sound they will bring to a finished guitar. After I select a set I join the two halves and plane them flat to a thickness of about 3 mm. It is then cut to the outline of my “plantilla” and the rosette is assembled and set in pace. When the glue is dry I plane the top surface flat again. Then I turn it over and plane to its final thickness, which might be anywhere from 1.6 to 2.6 mm. It is now ready for the various plates, bars, and braces to be added.
I might add that most luthiers these days, at least in North America, sand their soundboards to thickness with a thickness-sanding machine. It is quick and easy and fairly accurate. However, I gain much from planing by hand with a jack plane. I get a much more intimate dialogue with the wood. It teaches me things about toughness, the fineness of grain, irregularities in grain direction, color, etc.. All these attributes inform me intuitively about making good decisions about orientation on the rough set and final thickness.
Back and Sides
Before bracing the top I usually first turn my attention to the back and sides. The back, like the top, is typically made of two book-matched pieces, although 4-piece backs are not uncommon. These are joined with a decorative strip up the middle. After thicknessing, and here the thickness sander is my friend, I glue a reinforcing strip of mahogany to the inside of this joint and then three transverse bars of mahogany running across the joint. These bars are shaped to a gentle curve along their gluing surfaces and glued to the back in a mold in order to give a side to side arch to the back. When it is fitted to the guitar the contoured sides will give it a longitudinal curve as well. The result will be a slightly domed back with considerably more strength and ability to adjust to changes in humidity. The sides are planed, thickness-sanded and scraped to their final thickness before bending. Here the thickness may vary from as much as 2.3 mm to as little as 1.4 mm. Though I will insist most of the sound qualities of the finished instrument depend on treatment of the top, back and sides do exert their influences. For a quick, responsive instrument I will make the sides thin. For a little more sustain and a certain “solidity” to the sound I might leave them thick, or even double them in thickness with an interior lamination.
I used to bend the sides over a pipe heated with a propane torch. then I graduated to an electric cast aluminum bending iron. In recent years I have delighted in using a Fox side bender, powered by springs and 4 light bulbs (very high-tech!) Once bent, they are placed in an outside mold and solid linings are glued on. The linings serve the purpose of providing an interface between the sides and the soundboard and back. this is another step where design decisions can affect the sonic outcome. Linings should be stiff and somewhat massive to give the soundboard a stable perimeter to direct its energy in a productive way. Mine are two-ply ash or oak, with a third ply added around the lower bout of the top. That third ply makes a total thickness of about 7.5 mm. It also makes a noticeable improvement in the sound.
Bracing the Soundboard
It is traditional to attach 3 transverse braces to the upper bout: one on either side of the soundhole and one near the position of the neck heel-block that crosses under the neck-fingerboard assembly. Before these are added, however, it is necessary to add stiffening plates around the edge of the soundhole and under the neck assembly. My system has evolved to where I now double up the entire upper bout with a 2 mm plate. This is particularly useful as with the elevated neck system the upper bout is curved downward toward the back of the guitar and the continuous plate helps hold the curve.
Once the upper bout is fully braced I will turn my attention to the lower bout. this is where most of the sound qualities I am looking for can be set free. Until about 10 years ago I concentrated on an evolving fan-braced system, eventually settling on 6 fans with a “treble bar”, a bridge plate, and two lower “cut-off” bars.
The number, placement and shaping of these little struts of spruce and cedar can have a profound effect on the outcome. They support the top and help resist the inexorable pull toward oblivion from the strings, while giving shape to the frequency spectrum that defines the sound of the guitar. An entry on the FAQ page goes into some detail about how I am bracing guitars more recently.
When I have reached a satisfactory resolution of this process I am ready to fit and glue the sides. I attach an outside mold to my workboard and slip the sides in place. To make the proper fit it is necessary to have anticipated the swoop of the upper bout in the initial shape given to the isdes. This fit is refined as mortices are cut in the linings to receive the big transverse bars. When the fit is “perfect” the sides are glued in place and the heel and tail blocks are placed for and aft.
To complete the interior, corbels are placed over the esxposed ends of the big transverse bar below the soundhole to lock it in place. Now is the last opportunity to make an final adjustments to the interior. A wash coat of shellac is applied and the sides are morticed to receive the back. Here again, it is necessary to plane the edge of the linings that mate with the back to the subtle curve that defines its arch. When the fit is right, it too is glued in place.
Excess wood is now trimmed from the edges of the soundboard and back where they protrude beyond the sides, and the sides themselves are scraped clean. At this point all that remains to complete the box is to cut the rebates around the edges and add theh bindings and decorative purflings.
The rebates can be cut by hand, but most luthiers use some sort of router arrangement. Typically, the guitar is stationary and the router is hand-held. This is a very dicey and stressful procedure. For me, a better solution is to keep the router stationary and move the guitar through it. This is especially true with the elevated fingerboard design, which has a soundboard that is decidedly not flat. Here the router moves up and down on a linear bearing to follow the contour of the top of the box and is aways oriented properly with respect to the vertical sides. Two passes are enough to cut the rebate for the binding and one more completes the stair step needed for the purfling. An added bonus is that prior to routing rebates, the back and soundboard are easily trimmed flush with the sides. Liekwise, the assembled bindings and pruflings can be quickly and accurately trimmed flush and rounded over with the help of this router arrangement. The bindings are usualy off-cuts from the sides. The decorative purflings are all made in my shop from veneers and plane shavings. Each guitar has about a dozen different kinds of wood in these decorative elements.
Elevated Fingerboard and Neck
At this point I bring my attention to the elevated fingerboard and neck, which, in fact, I have already made in advance along with about two dozen more in a fit of power tool mania. The machine work is done but there is still a long way to go. Now I will index a neck to my workboard with pins and give a gentle curve to the surface that will eventually go over the soundboard above the soundhole. The box is now complete and the stage is set for assembly and shaping of the neck and fingerboard. The assembly process uses the box as a template. The heel is applied to the neck after being fitted to its eventual position on the box, and with the neck clamped to the box the fingerboard is glued in place. The fingerboard itself is ebony. the fret slots are cut in advance of assembly but the frets are not pounded home until the guitar is almost complete. For an extended description of all this you can check out the upcoming blog on the elevated fingerboard design.
Once the neck has received its final shaping, the finish process can begin. Almost all my guitars are French polished. this is a process whereby shellac, dissolved in alcohol, is applied with a fabric muñeca and rubbed on the surface of the guitar until the cows ome home, or until a kind friend yells in your ear “enough already!” It begins with filling the pores of the rosewood and mahogany. For this purpose fine pumice can be applied with the polish. When the surfaces are nearly filled, the neck and box can finally be joined. I glue them with a splince joint to add strength and index them to one another. Once done, the final stages of building up the gloss in the finish can commence.
Meanwhile, the frets are set and dressed. And just as the polish is beginning to look acceptable, one more bit of wood needs to be hovered over and pampered for a while: the bridge. Most of its shape has been determined in the dust, noisy power too phase, where it was fabricated along with all its sisters. Now it is selected to be applied to the guitar and with suitable hand tools is shaped to its final dimensions and weight. The soundboard is domed under the bridge. To fit the bridge to this I use a scraper. Once fitted, the polish is scraped clean where the bridge will go and they are glued together with the help of a vacuum pump.
As the glue dries and the guitar slowly comes to equilibrium, I typically work on the nut and saddle. These are bone, and I shape them to specifications determined by my research on intonation. Once these are completed, or nearly so, it is difficult to wait any longer before adding tuning machines and strings to the guitar for the first time. If I am patient I will find other things to do until the day after gluing the bridge. Even though I might do it sooner, a truer picture will emerge later… there is always more polishing to do.
I hope this overview gives some understanding of how I make classical guitars. I typically build one, two or sometimes three at a time. For me the best work is slow focused work. It is really the only way I know.