Making Your First Guitar
A Tutorial
Fingerboards and Fretwork
You'll get as many opinions as there are luthiers on this one. As previously discussed, wood for the fingerboard is generally quarter sawn and usually from some harder species known to wear well. Modern stringed instruments have generally been either ebony or rosewood, although more recent additions have been Pau Faro and Wenge (pronounded wen-gay). Maple has also been used successfully.
Necks generally have a radius or curvature, making them more comfortable on the hand and fingers. The radius chosen is often characteristic of the manufacturer. A compound radius for the fingerboard is possible and used by some manufacturers as well. Here, the neck has one radius where it joins at the body, and yet another where it leaves the nut. A gradual transition between the two takes place in between. Stick to a single radius on your first instrument and choose one that you feel comfortable with playing on. You can use a compass or trammel to construct some cards of various radii in order to check out finished instruments for the curvature you like and then use the same card as a gauge to finish your own instrument. The simplest way is to tie a string to a pencil and then push your thumb down, or place a thumbtack at various distances back along the string from the pencil Do around 9 inches to about 16 inches. At each length, place a piece of cardboard under the pencil. While holding the pencil upright, draw the curve dictated by the particular length of string. Using scissors or an X-acto® knife, cut out the curve and you have your gauges!
Taper the fingerboard to just about its final dimensions. This can be done on a table saw with a tapering jig, or just do it freehand with a hand saw or band saw. Then, plane to the outside of the lines you've drawn creating your taper.
Cut your fret slots. These should be large enough to hold the tangs of the frets securely, but be wide enough so that the fret can be hammered or pressed in with some ease and without distortion of the fingerboard. It will depend on the manufacturer, but around 0.22 inches should work. You can measure this with some machinist calipers, or some other such instrument. many saws will have a kerf larger than this, so be careful! Some good quality back saws will be in this range and can be adjusted to your needs. (Stew-Mac, Lee Valley, Garrett-Wade, etc.)
Some like to cut the slots while the neck is still flat or unradiused. Others prefer to radius first, then cut. If you cut the slots first, I personally find it easier to control the saw, but the downside is that when you radius the fingerboard, the center will stay your sawn depth while the edges will lose depth and will have to be deepened by resawing once the radius is added. Also, unless you use a very sharp plane, you may take nicks and splinters out of the neck as the plane blade catches the edges of the saw kerf. The other option is to radius first and then to cut the slots for the frets. The rocking motion of the saw sometimes makes it somewhat difficult to keep the saw blade perpendicular to the center line of the fingerboard, even if using a square as a guide. Mark the location of the fret slots very accurately using a good quality steel rule with the finest divisions you can obtain. Double check everything.
Fret Position Markers
Traditionally, these are made from Mother-of-Pearl (MOP) and appear in the form of round dots along the fingerboard. These can be bought pre-cut from any luthier supply. You can also buy square blanks and inlay them as squares or rectangles, or even cut out an elaborate design, but leave this for when you have some experience. Abalone, another shell, is often used. These days, inlay artists have used everything from precious stones to silver wire to inlay markers and designs. Stick to the good old traditional dots for a first instrument.
Dot sizes vary, but a quarter of an inch or 6mm is the most common, which is good, because this is a common drill size. I feel a brad point drill is best as it has lips on it which cut the edges cleanly while making the hole, whereas, twist drills just pull up the wood fibers as the drill goes down. This can make for a sloppy, chipped edge.
The hole is drilled to just less than the thickness of your MOP inlay material. I like to use epoxy to glue in the markers as it is very strong, sands very nicely and can be pigmented with tints to approach the colour of the neck, thereby making an almost invisible edge. I mix up the epoxy with appropriate tint, if any, then stick some in the hold using a small scrap piece of wood to spread it around. Press in the dot with attention to putting the better looking surface upwards. Then, cover the dot with a piece of plastic (cut from a plastic bag) or some waxed paper and clamp very gently. Several dots can be clamped at once with using a scrap piece of wood to bridge three or four at once.
Let the glue cure according to the manufacturer's recommendations. MOP sands very easily, so I just sand down to the fingerboard surface using progressively finer grits until the pearl is level and is being polished by the very fine grit. Any bubbles or imperfections can be filled with extra epoxy or cyanoacrylic glue. Some luthiers place some tinfoil or such under the Mother-of-Pearl prior to gluing them in reasoning that the shiny metal surface will reflect out more light , making the dot slightly more brilliant. Fancier inlays are done in the same way, but the cavities are best made using a Dremel® rotory hand tool with a very fine bit, or even hit up your dentist for some used dental burrs. The Dremel® tool is mounted in a router base so that an even depth can be maintained. Trace your inlay onto the fingerboard or headstock where it is to be inlaid and scribe around it with a sharp carbide tool or X-acto® knife. Rub some powdered chalk into the scribed groove to make it more visible, if necessary. Then, with a steady hand route up to the line, or just before reaching it. Clean up with some fine chisels and epoxy your design in place. Inlays tend to look better on dark backgrounds as the glue joint is just easier to blend in.
Fretting
Fret wire can be bought in various heights, widths, composition, etc. Much of what you use will be personal preference with what is available to you. It is sold in various ways from 100 foot rolls to "by the pound", to precut lengths sufficient to finish one project. Very quickly, fret wire consists of the crown, or the area above the surface of the fingerboard that will make contact with the strings, and the tang, which anchors the fret into the fingerboard. The tang usually has some barbs on it to further increase the surface area and provide friction to hold the fret in position.
Some of the earliest frets were simply a piece of leather tied around the neck where a note would be formed. The wet leather when applied and tied, would later shrink as it dried, making a secure rise on the fingerboard where desired. Shellac or other finish could be added to harden the leather and make it permanent. Later frets were simply a wire hammered into the neck where notes were located.
The T-shaped fret was developed this century and vintage instruments had this fret wire hammered in being held in place under its own grip. More recently, adhesives have been used in installing frets. Clearly, some makers wanted to make their frets more secure, never to move and create a buzz or rattle. Some went as far as using epoxy to secure the frets, thereby making them all but permanent. This is generally frowned upon these days. Glue should not really be necessary with a properly radiused and installed fret. Many manufacturers still tend to use some form of glue while installing frets, but this is not so much to create a bond between the fret and the wood. Rather, slightly diluted hide glue (liquid or hot) sparingly applied or wicked into the slot to (a) lubricate the mechanical action of pushing the fret into the neck material, (b) swell the wood fibers to hold the fret initially, and (c) bind the ends of the wood fibers in the slot right up to the surface of the fingerboard making it less likely to chip and splinter in the future. If you need glue to keep your frets from falling out, you've got problems!
Frets have to be radiused to the contour of the fingerboard. There are jigs and tools that can do longer lengths at a time, but chances are that you don't have one, so just cut the fretwire about a quarter inch or slightly longer than you need, keeping in mind the taper of your neck. They are best cut using wire nippers (pliers for cutting wire), but a hack saw or rotory tool with a cutoff wheel will work. Using a pair of pliers, gently bend the wire to conform to the radius of your fingerboard. You will probably have to go up and down (back and forth) along the segment of fretwire until you get the desired curvature. Some luthiers recommend leaving a bit of spring in the fretwire to give some tension after it has been hammered home, but I've never seen any advantage to this if properly seated in the first place.
Frets can be installed a number of ways. They can be pressed in using a curved caul and a drill press or arbour punch (see Stew-Mac). I believe it was Fender® that once installed them by pushing them in sideways through the slot, but the traditional method is still to hammer them in one at a time. Just about any hammer can be used, although ones with a brass, or even plastic head, may marr the surface of the frets less. They may not have enough mass in them to get the job done, so it is better to use a good sturdy hammer with a relatively flat face and no engraved pattern to prevent it from sliding off nails. Again, there is the argument as to whether it is best to start at one edge and work across, or to start in the center and work towards each end. I prefer to start at one edge and work across as I feel this way, the fret is always moving in one direction while going down. If hammered from the center to each edge, there is some slight movement to one side and then to the other, enlarging the areas around the barbs on the tangs creating more play and less grip. This is probably a very minor point and I would develop and go with the technique that works for you.
The fret should seat itself flush with the fingerboard. Don't fiddle with this too much as too much moving will further loosen the fret resulting in a poorly fitting fret or a buzz when playing. Wick some thin cyanoacrylic glue into the fret slot from the end and then gently clamp the fret down. Several can be clamped off at once with a slower drying glue. Let the glue dry overnight. Remove any clamps and trim back the ends of the frets until they come very close to the edge of the neck. The further away you are, the more filing you'll have to do. Using a medium coarsness bastard file, I carefully file until the end of the fret is all but flush with the side of the neck. I blend the crown into the edge as it drops off the side of the fingerboard so that it is smooth to the touch and looks streamlined. A finer cut file (needle files) can be used here to remove any marks left by the coarser file.
The care taken in the preparation of the fingerboard will be reflected in the accuracy in which the frets all are equal in height after installing them. Buy a good quality mill file some 10 to 12 inches in length. If possible, compare them at your tool supplier for flatness and when you have found a good file, dedicate this to fretwork and nothing else. In order to level the frets and make sure they are all the same height, gently place a file onto the surface and push along in one motion the entire length of the neck. In order to check for even frets, color the metal crowns of the frets with a contrasing magic marker (I like dark blue) and file again. The ink will be removed from the frets in contact with the file (the frets that are flat), but not from any depressions. Concentrate on these areas until they are "feathered in" and the surface is flat from one fret to another while preserving the fingerboard radius edge to edger. A long block of hardwood can be used to back fine grits of sandpaper, as long as you are assured the wood is flat. A thick piece of plate glass or metal can be used, each with their own associated problems.
Specialized Tools
Specialized tools can be bought which are specifically designed to make the task of fretwork easier and more accurate.
Light weight rectangular metal bars or tubes ground for flatness and impregnated with industrial diamonds are available. These assure an accurate surface, have a reasonably aggressive cutting action, but not the chatter associated with files. Although somewhat pricey, they are a good investment for the serious builder.
Fret levelers can also be bought that are made from a durable plastic and have been made with the fingerboard radius designed right in. Several popular radii are available. Here, you would apply sticky-backed sandpaper to the leveler and run it up and down the frets in long strokes of equal pressure to make the fret height uniform.
Final dressing of the frets has traditionally been done with a small fine triangular file. Some skill is needed to be developed here to get the crowns even and not to marr the surface of the fingerboard. It is recommended that you tape off the fingerboard area with masking tape or purchase some thin stainless steel finger board protectors (Stew-Mac) to reduce or eliminate this possiblity. One slip with the file can put a nasty gouge into a beautiful fingerboard, which will be hard to repair. Once again, specialized files are available for the job and make the work easier and more consistent. Waverly makes a fret file which is a small file mounted on a curved handle to keep it from contacting the work surface. The file surface is concave, so by choosing the correct width, the file will fit right over the crown fo the fret and you can file away to remove excess material or round over the crown to its original form. Now, diamond impregnated fret files are available in various fret wideths and frit sizes. I highly recommend these as they are fairly aggressive and leave a clean surface. Well worth the $50 to $60 they cost.
The frets should be level from the nut to the end of the neck with the possible exception of relief in the region of the 9th to 12th fret.
Good quality straight edges of various heights are useful here as a long straight edge can be placed against the frets to look for any discrepencies in height. Relief can be measured by using a small straight edge perpendicular to the bottom of the long straight edge. Small straight edges can also be used to bridge just a few frets at a time to see if there is any rocking motion present indicating a high spot.
Final polishing can be done with a very light touch of very fine grain sandpaper or Micromesh®. The 4-0 or 0000 grade steel wool has been also used, but be aware of the possibility of metal splinters. You might even try a rotory tool with a small buffing wheel loaded with a fine jeweler's rouge to take out any fine marks and polish up the metal. Any oils or residue from the polishing process can be removed with some naptha on a soft cloth. (Be sure to test it on an inconspicuous sample of your finish to make sure it is compatible). You can apply a fine fingerboard oil, if you desire, to soak in and protect the wood. Once again, if you do, stay away from compounds containing silicone.
It takes awhile to become really good at fretwork, but if you have some common sense and some patience, you can do a fine job, even with the most common tools.
