Notes on Tools

(under construction - expect to see more photos and material on use and other ruminations)

I purchased a few specialist tools for this project, probably more than I should have. Perhaps the most dubious purchase was a set of nut-slot files, which come in a wide variety of precise widths to match the sizes of guitar strings. They were not objectively expensive, though taken together it came to a piece of change. Imagine my consternation when I read how you can use a cast-off piece of guitar string to saw the nut slot to an exact fit for a string of the same size.

Most of the tools used, however, are ordinary woodworking tools. I like Japanese handsaws because I can't clumsy up and kink them while pushing through the cutting stroke too energetically -- they cut on the pull stroke. A good block plane is essential, at least if you're me. I like the Stanley low-angle model with the adjustable mouth, which you see in a good number of pictures in the journal. Chisels good and bad -- the bad one is for chipping dried glue squeeze-out. Rasps and files, along with an aggressively-cutting  Microplane or Surform tool. And, much as I prefer to use hand tools, I resort to the router, bandsaw, and drill press when specific operations match their strengths. Yes, and a jointer. I know I could use a jointer plane; I'll get one someday and wean myself away from this beast. 


These are the handsaws I'm using. At the top is a small ryoba saw. It has crosscut teeth on one side and rip teeth on the other. At the bottom is a Dozuki. Its tiny teeth leave a clean kerf of no more than 1/32". The dozuki is new today (Mar 24), bought to replace one that has hit the concrete floor in my basement shop too many times. In using it on the mahogany neck of the steel-string guitar project, I find it cuts 1/4" deep on a single stroke with no downward pressure other than the negligible weight of the saw. And straight and smooth -- it is a pure joy to use. The Japanese saws' teeth are sharpened to cut on the pull stroke, which I find much more comfortable than the western saw's forward-cutting teeth. So the coping saw in the middle is set up with the blade "backward", too.

Early luthiers used a metal pipe that sat atop a box of hot coals. Some moderns use a pipe into which the flame from a blowtorch is directed. Having had a house fire once, I preferred an electrical marvel with a thermostat to keep it from overheating. And what does it do? It provides heat and a curved surface against which the luthier can bend the wood for the curved sides of an instrument. The wood for the sides is soaked briefly (fifteen to thirty minutes) in water, then worked against the hot bending iron. The iron is hot enough to force steam into the wood from the water soaked into the surface, and the heat and moisture plasticize the fibers of the wood, allowing it to bend. When the wood cools, it retains the shape it was bent into. 

Some luthiers, and pretty much all factories, use bending machines that form the wood around heated molds. If I want to make a differently-shaped guitar each time I build (and I probably will), I can dispense with the expense and effort of mold-building by shaping my sides free-form using a bending iron. 


These are aluminum bands that are fitted to the bending iron for bending thin material, like purfling, that is thicker than side material. The bands are set apart a distance equal to the width of the material, and can transfer heat to the full thickness, allowing it to bend. They also mechanically keep the bending material from twisting, as it might if it is thicker (in the bending plane) than it is wide (in the surface against the iron).


This ordinary fly cutter is used to cut the soundhole out of the top. Note the cutter is angled to a point with the flat surface out; this gives a soundhole with a straight wall. I didn't use this to rout the channels for the rosette, but with a squared-off cutter, it could be used for that. The cutter in that case acts as a scraper, scraping down the width of the channel. This cutter, however, has a maximum radius of two inches, which is too small for such a use.


This is a fore plane, a somewhat obscure member of the family of bench planes that includes the block, smoothing, jack, and jointer planes. The fore plane is longer than a jack, but not as long as a jointer. The somewhat unhelpfully placed ruler on top of the book is six inches. Because of its long sole, it lifts the cutter over small dips in the surface, allowing it only to cut away the higher points, so it can accurately level a board all along its length. This is also the function of the jointer plane, so many folks skip this one. I don't happen to have a jointer plane, so I use this for that purpose. It works well on pieces the length of an x-brace, which is what I used it for on the guitar. It has a corrugated sole to reduce drag, which isn't much of a factor on things as narrow as braces, but can be a big help when using this fairly heavy plane on wider surfaces. I picked this up at a junk shop for $25.00; it was in almost perfect tune, the sole nice and flat and the cap iron ground well. The blade just needed normal sharpening. I got quite a bargain!

A spoke shave is like a plane with a very short sole, which may be curved or straight in both directions, i.e., it may be curved along the sole perpendicular to the cutting edge, and the cutting edge may be curved as well. As its name implies, it was originally conceived to shape the spokes of wagon wheels, which are not round, but rather a flattened oval shape. In guitar building, it is used to shape the flattened oval of the neck. This spoke shave belonged to my grandfather and still hums along, as you can see by the long curls of mahogany coming out of it here. 

 


Copyright 2001 Stephen Miklos