Play Safe, stay healthy,
As usual, if you have any questions, feel free to contact Woody.
Note the maple strips inlaid on both sides of the truss rod. These strips are inlaid nearly as deep as the neck is thick. They create a lamination that strengthens the neck considerably. On previous guitars I used carbon fiber for these strips. I felt that the neck was almost TOO stiff when carbon fiber is used. It made it more difficult to get the proper neck relief. So, back to maple.
When installing the truss rod, be sure that it will be completely buried below the surface of the neck when epoxied in. Also, the allen wrench adjustment at the nut end should not extend above the peghead veneer. An alternative is to access the truss rod thru the sound hole of the guitar. That means turning the truss rod around, obviously. But it also creates challenges in access and/or structural integrity… too much for us here.
Once the truss rod has been positioned in the dry, remove it and apply epoxy to the sides only. Quickly embed it back into the truss rod slot. Clamp as needed. One does not want to get epoxy on the rod itself which is inside the steel channel housing. The rod that I use comes with masking tape covering the open side of the 3-sided steel channel. The truss rod pictured here is with the tape side up, but it is actually installed with the TAPE SIDE DOWN.
Finally, epoxy fill (or wood shim) the gap between the top to the truss rod and the neck surface after the rod is epoxied into the slot (or you can use a shim). Sand the epoxy flat with the neck surface when cured. That way, the neck and fretboard form a solid mass except for the operating part of the truss rod which is encased in the steel truss rod channel.
Oh, one final thing. Wear surgical gloves when messing with epoxy. Otherwise, you might be looking at black epoxy under your fingernails for a week or so.
CHECK NECK ANGLE (again)
There is one final check before the fret slots are cut. We need to ensure that the surface of the radiused fretboard, w/o frets, aligns with the top of the bridge.
Here's how: With the bridge and fretboard in place (but not glued) a straight edge laid on the top of the fretboard (on the centerline) should align with the top, center of the bridge. By design, this should be 9mm off the surface of the soundboard.
INSTALLING THE FINISHED FRETBOARD
At this point, the bottom of the fretboard should be a true, flat plane (or very slightly concave) and each edge of the fretboard should be perfectly straight and square to the bottom surface of the fretboard. The nut end of the fretboard should be square to the centerline and the proper distance from the 1st fret.
When the fretboard is positioned so that the 14th fret is directly above the junction of the heel/body assembly, the sound-hole end of the fretboard is scribed and cut in an arc concentric with the sound hole so that the rosette pocket is completely covered. Depending on the design and layout of the rosette, this should be only a few millimeters from the edge of the sound hole.
FRET SLOT DEPTH
Check the depth of the fret slot with a short piece of fretwire with the barbs removed as shown here.
PRESSING IN FRETS
When the position marker inlays are complete and final sanded, and the fretboard width is at its design dimensions... 43mm wide at the nut and 57mm wide at the 14th fret on Woody guitars. This will result in a string layout of ~57mm (E to e) at the saddle. The fretboard is ready for frets.
The fretwire that Woody buys comes in a 20-foot, 12-inch roll so it is already curved to the approximate radius of the fretboard surface. It is very helpful to use pre-radiused fretwire.
> Cut 20 frets out of your stock. Make the frets about a half inch longer than the slot they are intended for. Line them up on a piece of masking tape to keep them in order.
> Start installing from the nut end, i.e., first fret, second fret, third etc. That way, if something goes wrong, you can just pick up the next in line and be sure that it is long enough.
> Working with one fret at a time, put a little super glue into the ends of the fret slot (last quarter inch or so) and then place the pre-cut fret into the slot and lightly tap it in... just enough to keep it in place while you place it in the fret press.
> With the fret sitting on top of the slot (and the super glue setting up), put the fingerboard into the press. Carefully place the fret caul so that it is aligned and slightly engaged with the fret. Crank the vise down slowly and press the fret into the slot. If your fretboard has been shaped to the same radius as the caul, you will have a perfectly seated fret. Just to make sure, I keep the new fret under the press for 30 seconds or so to let the super glue set up.
> Take the fretboard out of the press and clip the ends of the newly installed fret. Be careful not to lift the end of the fret.
> Now... do this twenty times and the fretboard is finished.
NOTE: If a fret is going to come loose, it will be at an end. That’s what the super glue is for. If the fret needs removal for any reason, a little heat applied to the fret with a soldering gun will break down the super glue cleanly and completely.
THIS MIGHT HELP... later Do not put a fret in the second and tenth fret slots at this point. This will allow you to drill a tiny (1/32") hole, about a half inch from each end of those two fret slots. Each of the 4 holes will accept a 3/4” brad for pinning the fretboard in place when gluing it to the arm. Otherwise, the fretboard tends to slide around when clamps are applied. The brads are pulled, and the slot is cleaned up after the glue joint is cured (48 hours).
Chapter 10_ Fretboard and Frets
Smooth, even strokes with the saw are important to achieve the best results. Also, the fretboard must be firmly fixed in place.
The distance between the fences is 78mm as the fretboard stock is 76mm wide. That leaves room for a 3mm wedge at each end to hold the fretboard up against the opposite fence while the fret slot is being cut.
The saw blade travels in vertical slots in the fences. These fence slots are aligned so that the path of the blade is perpendicular to the fence, therefore, perpendicular to the centerline of the fretboard.
After a fret slot is cut, the fretboard is moved to align the next layout scratch directly under the backsaw blade. The mitre box has three sets of fence slots to guide the backsaw. One set of fence slots is in the middle of the mitre box and one set is near each end of the box. These end slots are for convenience when cutting the fret slots near the ends of the fretboard.[A picture containing text, wooden, tool, wood Description automatically generated] The entire box, fences, and base are assembled as one piece and screwed onto a workboard that is held rigidly in a vise underneath. The mitre box fixture has one purpose. Woody has never used it for anything but cutting fret slots.
If you would like a brief explanation of how to radius the fretboard on a CNC machine, see Woody's Journal entry for November, 2018.
The top edges of the fretboard and the fret ends should not have any sharpness. They can be rounded to a smooth feel with 320 grit sandpaper.
As the final carving proceeds, don't be shy about unclamping the guitar from the workboard and sitting down with it in your lap to check how the neck feels in your hand. Ultimately, that will be the test of your carving... whether or not the neck is comfortable in the player's hand.
For a smooth feel in the hand, the flat fretboard edges should be carved into a continuation of the curve section of the arm of the neck... as pictured here.
FRET SLOT LAYOUT
With the fretboard surface radiused and neck angle adjustments completed, it is time to layout and cut the fret slots.
The first requirement is to keep the fret slots exactly perpendicular to the center line of the fretboard. Start with the nut. The fretboard stock is not always perfectly square on the end. Often the board is wider at one end than the other. So, be diligent and mark the center of each end of the fretboard. Masking tape helps keep the line visible. Then connect the center marks on each end with a line down the center of the board, also on masking tape.
If the edges of the board are not parallel to, and equi-distant from the center line, it is necessary to make them so now. This ensures that a line, or saw kerf, perpendicular to the edge of the board will also be perpendicular to the centerline.
Check the nut end of the stock to ensure that it is cut perpendicular to the center line. If it is not, make it so now_ before you start the fret layout. Once the fret slots are cut, it's too late to change the position or angle of the nut.
To layout the nut and fret spacing, Woody tapes or clamps a fret rule down the center of the board so it can't move while marking the fret positions. Use an X-acto knife to mark the fret layout at the very center of each fret mark on the rule... just a short, firm scratch in the center of the board is what you want.
NOTE: Radiused and slotted fretboards, as well as many of the jigs, fixtures, templates and finished guitar parts described in these pages, can be purchased from reliable suppliers online. Woody's discussions and recommendations assume that the reader is a home-shop luthier who enjoys building more than buying.
I believe that an entire guitar building kit can be purchased for $600-$800 or so... one would still need tools, clamps, jigs, a workbench, etc.
Woody would rather build things himself... it's a family tradition.
The photo below shows a two-way adjustable truss rod. The truss rod is set into a 1/4" (6.35 mm) slot routed into the neck. Some luthiers apply a thin silicone caulking into the bottom of the truss rod channel to ensure against rattling. Woody wraps tape over the threads at the nut end to keep them clean during this process.
Pictured above is what Lowes calls a "6 in. Portable Carpenter's Vise". It costs about $20 at Lowe's. To this vise I added wood block on each jaw. One of these blocks has a 1/4" hole drilled in the center to accept a StewMac Fret Press Caul. The vise/press is mounted to a small workboard which is turned 90 degrees when held vertically in the Versa vise so that the handle is on top. This puts gravity on your side when aligning and pressing in frets.
This set up works quite well and can generate far more compression torque than you will need. Woody has been using this rig for about 10 years.
NOTE: It is very helpful to purchase pre-radiused fretwire. Woody uses 12" radius, medium width and height, fretwire.
RADIUS THE FRETBOARD
Before the slots can be cut, however, the fretboard surface needs to be shaped into a curved radius. The thickness sander is used to rough out the radius curve by creating three flat surfaces in an approximation of the desired radius. This saves a lot of shoulder work. (see diagrams below, 3 Flats)
After the thickness sander creates two facets on the fretboard surface, radiused sanding blocks (from LMI or Stew Mac) are used to finish developing a smooth radius across the width of the fretboard. Woody uses a 12-inch radius on his finished fretboards.
There are a variety of tools available to radius the fretboard. The aluminum sanding block shown here is available from Stew Mac but, I have to warn you, it takes a lot of shoulder and triceps strength to muscle-sand an ebony or rosewood fretboard from flat stock to a 12" radius. That's why I begin with the fretboard stock on a jig that I send under the drum sander (one pass bass side, one pass treble side). This makes a somewhat trapezoidal cross section in the fretboard, but all that's left to do by hand (and shoulders) is to sand down the facets and radius the flats in between. This is much easier.
To cut the frets accurately by hand, Woody has constructed a mitre box specifically for that purpose. It's made from hardwoods and plywood in order to keep it true and stable. The depth dimension of the box is specific relative to the width of the blade on Woody's back saw. In this case, 41mm. Of course, the kerf of the blade (0.020") is also critical as this will be the width of the fret slot that accepts the tang. Make sure that you carefully note the depth and kerf dimensions of your chosen backsaw. Wider frets require a wider kerf, i.e. different backsaw. If the kerf is the correct width, the barb will hold the fret in place.
With the layout etched onto the board by the X-acto knife, the positioning of the board under the saw is done manually by hand, eye and feel of the saw in the etched mark. The X-acto-etched layout also helps keep the first stroke of the back saw exactly on layout. The first stroke of the back saw should be smooth so as to keep the saw blade in the X-acto ker [Diagram Description automatically generated] F.
At this point, the edge of the fretboard stock is parallel to the center line and pressed firmly against the one side of the miter box. This keeps the fret slot square to the centerline. The miter box, by design, is several mm deeper than the width of the backsaw blade, so it stops the cut at a fixed and consistent depth without fear of cutting through the fretboard. The fences on both sides of the box are 44mm tall. The back saw blade is 41mm wide (max depth of cut).
FINAL CARVING OF THE NECK AND HEAD
When the glue joint of the fretboard and arm has cured, the neck is ready for final carving. At this point, there should be very little carving left to do as the bulk of the carving takes place before the neck is joined to the body. These procedures were touched on in the last chapter. Some details are added here.
[A picture containing text, table, indoor, office Description automatically generated] Mask the soundboard, sides and back of the guitar, and clamp the guitar on a workboard with the neck extending out so that it can be carved from both sides.
It might take a little elbow grease to muscle down the facets on the ebony with the sanding blocks. Woody uses 60 grit paper only until the flat facets are no longer defined. Then switch to 80, 120 and, finally, 220 or 320 to complete a smoothly radiused surface. Ebony can be sanded quicker if you secure the stock to the workbench and position yourself so that the weight of your shoulders is on top of the sanding block. A smooth arc, end to end, will make the installation of frets much more uniform.
Like many of Woody's guitar-making ideas, the process for installing frets has evolved over the decades. For many years, I hammered in frets with tools specifically made for that purpose. That is, a fret hammer with a brass head. More recently, in the past 10 years, Woody and I have contrived a method of pressing in frets that is more controllable. Both devices are pictured here.
Of course, one also has the option to purchase a manufactured fret press.
If the straight edge indicates that the neck angle is not what it should be, there are a few ways to remedy that.
THICKER OR THINNER BRIDGE
The bridge could be a little thicker or thinner. The thickness of the bridge impacts the tone of the guitar slightly. I doubt, however, that the human ear could detect an audible difference in a single millimeter on a steel string, dreadnought guitar.
TALLER OR SHORTER SADDLE
A change in the height of the saddle above the bridge would impact the break angle of the strings. This, in turn, impacts the stiffness of the strings relative to the player’s attack. A finger picker might actually prefer a greater break angle.
WEDGING THE FRETBOARD
The thickness of the fretboard could be tapered at one end by sanding down the underside or adding a thin wedge between the fretboard and the arm. 'Wedging' the fretboard impacts the thickness, feel and playability of the guitar neck.
FRETBOARD INLAY (Position Markers)
Woody recommends putting inlays into your fretboard before the frets. The obvious advantage is that it's much easier to sand them flush with the surface of the fretboard. If you are planning to inlay 1/4" dots, be sure to use a forstner bit as a twist drill bit usually chips the edge of the ebony at first contact.
If one wishes to use position markers that are dots, one can either purchase pre-cut perfectly identical position markers, or more elaborate precuts with a theme (like leaves, or bear tracks, etc.). Just remember, the pockets for these shapes need to be carefully routed into the fingerboard... by you. If you have never done this, I would start out with dots.
Woody's complete discussion of inlay work will be delayed for now. In a later chapter, the peghead, bridge and fretboard inlays will all be explained at the same time.
INSTALLING THE TRUSS ROD
The truss rod channel in the neck was already routed to dimension before gluing the dovetail to the guitar body. The routed channel might need to be extended into the heel block. Personally, I do this after gluing the dovetail.
The construction of the fretboard is now complete. The only thing left to do is glue to fretboard to the arm of the guitar ensuring that the fretboard centerline and the centerline of the arm/body stay aligned as the glue joint cures.
The glue joint is basically a lamination and comes with the usual problems with slipping and sliding when clamped. As described above, Woody pins the fretboard to the arm by installing a brad near each end of the 2nd and 10th fret slots.
Use a rigid, straight, and true caul as a Stiff Back (pictured is a 30” mason’s level), to keep the neck and fretboard from warping as the glue joint cures. Keep the Stiff Back, the fretboard, and the arm of the guitar clamped together for 48 hours.
Now we get personal. The width, radius and scale length layout of your fretboard is a matter of personal taste and style. A classical fretboard, for instance, is flat and wide with a shorter scale length when compared to the traditional steel-string dreadnought that Woody builds.
In this chapter we will explore the home-shop methods that Woody has developed over the years to build and assemble the fretboard. Whenever Woody teaches or discusses the guitar-making process, it seems that building the fretboard and spacing the frets creates the most anxiety in the mind of freshmen guitar builders. Here, Woody presents straightforward methods and details of fretboard layout and construction which are critical but relatively easy to execute, assuming that one has a fret rule to layout the fret slots.