Carving the neck is one of the most enjoyable parts of building a guitar. The blocky, chunky neck blank is turned into a sleek, smooth guitar neck.
The neck stock is first tapered. I use a neck width of 1.7″ at the nut, and 2.1″ at the 14th fret, where the neck joins the body. The neck taper is marked, and the peghead outline is drawn on the peghead stock.
The lower portion of the taper is sawn first.
Then the peghead outline is cut, and smoothed with a spokeshave and rasp.
The taper on the neck is now finished with a plane and files; the file is needed since the curve of the peghead will prevent the plane from reaching that end of the fretboard. The sides of the taper should be made absolutely straight.
For carving, the neck is clamped to a carving jig. There’s a wedge underneath the peghead to support it.
The neck thickness is first established at the 2nd and 10th frets by cutting grooves at these positions to the correct depth. For this neck, I’m using thicknesses of .550″ at the 2nd fret and .600″ at the 10th fret.
The neck thickness is measured as the groove is deepened. The hole underneath the groove position is exactly 1″ from the top surface of the jig to make measurement easier.
The neck after the grooves have been cut – ugly, but the depth references are important to ensure the neck is thinned to the correct thickness.
I then lay out a pattern for a curved-diamond detail on the underside of the neck-peghead joint, below where the trussrod groove ends. This is not absolutely necessary, but helps to strengthen the neck in this area, and provides a nice sculptural detail.
The heel profile is marked on the heel of the neck blank.
The neck is now thinned with a drawknife and spokeshave. The neck is thinned linearly between the two grooves.
The neck taper is checked to make sure the surface is straight between the two grooves.
The heel is rough-shaped with a bow saw, then shaped with drawknife, chisels, rasps and scrapers.
The peghead diamond detail is trimmed next.
The neck is shaped further by carving facets on either side. This helps to ensure the rounded neck will have a consistent profile. The facets here are 11/16″ wide, and extend down to 3/16″ from the top surface (i.e., there’s a 3/16″ facet left on the sides of the neck).
The neck is finally rounded between the facets with a spokeshave.
The peghead diamond shaping is completed, merging it with the neck.
At this point I often glue on a decorative overlay on the peghead, using either the material used for the back and sides or some contrasting wood. The overlay is cut roughly to the peghead profile and the neck glued to it as shown. The overlay is trimmed flush to the peghead profile after gluing, and the truss rod slot is chiseled out. The final step in constructing the neck is drilling the holes for the tuning machines. Most have 10 mm diameter bodies, so a 10 mm diameter drill bit should be used.
The neck can now be sanded for final smoothing, using curved sanding blocks as needed to smooth and refine the shapes.