Shaping the Neck
It is now time to shape the neck. I use nothing but hand tools to complete this process; that is how I have always done it. I have gotten a lot faster over the years and have developed a pretty good feel for the process without having to make frequent stops to make measurements, but I am always mindful of the fact that a mistake in this process could ruin all of my work up to this point. One misplaced pull with the spokeshave could ruin the neck and force me to rework a great deal of the guitar, so I stay focused while I am shaping the neck and try not to rush.
The bulk of the excess neck wood is removed with a spokeshave, which is basically a plane with a handle on either side of the blade. The guitar has to be held steady while both hands are holding the spokeshave. The best way I have found to do this is to lightly “clamp” the guitar body between my knees while I sit in a chair. This is pretty low-tech, but it works for me.
The spokeshave works as it is pulled toward me, so it starts at the heel end of the neck and is drawn up toward the peghead. I slowly rotate the spokeshave around the neck, changing its position with every pull or two. Here are some pictures of spokeshave being used:
After the bulk of the excess wood is shaved away, I switch to rasps to continue the shaping process. Rasps are a very sharp and aggressive type of file. Like the spokeshave, rasps can also cause disaster pretty quickly, so again at this stage I am very cautious. I no longer need to cradle the guitar body between my knees. I use one hand for the rasp, so the other one can hold onto the guitar. You can see in this picture that the neck is beginning to take shape.
When the neck feels about right, I take a few measurements with a caliper and do some final thicknessing with the rasp. Most players want the neck to be shaped symmetrically from side to side. I used to use a pattern gauge to check for symmetry, but gradually got to the point where I could tell if it was the desired shape by running my hand across the surface, so the pattern gauge rarely comes out now. As far as thicknesses, I generally want the thickness of the neck at the first fret to be about 0.800″ and at the 10th fret about 0.900″ unless my customer specifies something else. These dimensions seem to be comfortable to most players.
After the main shaft of the neck has reached its desired thickness and shape, I still have work to do in the transition areas around the heel and the beginning of the peghead. This is done with finer rasps and eventually scraper blades.
Once I’m satisfied that the neck is shaped properly and that there are smooth transitions to the heel and peghead, I go over the entire neck with sandpaper, usually starting with 100 grit and finishing with 220 grit. Then I sand the body of the guitar, also up to 220 grit. The construction process is now complete. The next step will be applying the finish.