OK, the fretboard is made from our slab of East Indian Rosewood. This is then rough sawn into “blanks” roughly 1/3 of an inch thick, 20 inches long, and 3 inches wide piece. I use the band saw for this. The board yields about 6 blanks. I’ll use one for this guitar and save the rest for other builds. I take this blank and flatten one side on the jointer and plane the top to clean it up and make it a perfectly even thickness about .223 inches thick.
We mark out the fret locations on the board and cut the slots. I use a purpose built miter box and a japanese fret saw. As you can see here all the slots are cut, but the board is totally flat which is good for aligning and cutting slots, but no good for a finished fingerboard. They need to be curved to some extent. The degree of the curve depends on personal preference, and what styles of music will be played.
The radius (12″ in this case) is sanded onto the board using a sanding block with the correct radius. Radius is the curvature of the fretboard. They are slightly rounded, not flat. What is meant by radius is if you imagine that curvature continues all the way around to form a circle, the radius of that circle is the distance from the center to the edge of the circle. The smaller the radius, the more pronounced the curvature of the fretboard.
Takes a good while to get it sanded. Its a good workout 🙂
Here is the board after sanding
You can see the curvature from this angle. If you continued this curve all the way around to create a full circle it would be 2 feet in diameter. The radius of that circle is therefore 12 inches. This is the commonly used way of describing how curved a fretboard is. Different types of guitars can range from 9 inch to 16 inch radius. The higher the number, the flatter the board. People tend to have definite radius preferences depending on what styles they play.
I then tape up the board and place the inlays where they will be and trace the outlines. These are standard trapezoid shaped inlays found on Les Pauls. Gibson uses plastic inlays on all their guitars, but I am using Mother of Pearl for my guitars. I find its harder, smoother, and much more lusterous.
Then I use a scalpel to cut out the area that will be carved out for the inlays.
Then I use my dremel to create a flat bottomed cavity that matches the thickness of the pearl in the middle. Once glued in the inlays will sit higher than the board near the edges since the board is curved. This will then be sanded flat and flush with the board.
Once I have the outline well defined I remove the tape and deepen and clean up the cavities until each piece fits as precisely as possible.
Once finished, I glue in the inlays using clear epoxy mixed with rosewood dust that I saved when I sanded the radius. This will color the epoxy the same shade as the wood. Sometimes you get slight gaps between the inlay and the edge of the cavity, and the rosewood colored epoxy perfectly fills them and makes them dissappear.
All sanded down flush using 600 grit paper. Shiny!
Ok back to the body. The tops on Les Pauls are carved to a nice smooth curvature. Some call these “Archtop” guitars. To do this I made a series of templates to use with the router to cut concentric steps on the top.
These give me the basic shape to follow. the steps are then smoothed out using a curved cabinet scraper followed by a random orbital sander.
After routing the steps we need to carve the neck and pickup planes. I built a “box jig” that can be set to any angle I need to carve the very specific angles needed to make the shape of the top flow the way it needs to…Please excuse the fuzzy photo…
Once the pickup and neck planes are carved we can start smoothing off the steps to achieve the final shape of the top. I used a random orbital sander and a lot of hand sanding for this.
Then the pickup cavities are cut. This step eliminates the dowel pegs I mentioned earlier