Brian's Guitar from Conception to Birth or How to Build a Guitar in 62 Easy Steps!
13 Rough Cut the Neck's Shape
All of your layout lines should still be on the top of the neck. Some of those can be transferred to the side of the neck. A few other dimensions you’ll have to “carefully” mark (there’s that word again). The neck on our guitar actually penetrates about a foot into the body. This takes a little more layout and a few more cuts. After double-checking your marks, cut out the shape on the bandsaw about 2mm outside your lines. I gave about a 5mm margin where the end of our fretboard jogs to penetrate the body. I want to double (and triple) check that the end of the fretboard will be exactly where I want it. I won’t cut this until after the neck is dry-fit to the body. Now you just have a lot of clean up to do to get your cuts to be precisely up to your layout lines. The first photo to the right shows a horizontal/ vertical edge sander. This is a great tool if you have access to one. This will take care of leveling most of your straight edges. Just slowly work up to your layout lines with light pressure. For tighter areas and curves, use an oscillating drum sander (second photo). You can also use this on straight edges you couldn’t reach with the previous sander. Just pay more attention to creeping up on your layout in a straight line avoiding any scalloping by pressing too hard in one spot. If you don’t have access to these tools, you’re shit out of luck. It will take a lot longer using hand planes, belt sanders, and orbital sanders.
Now it’s time for a test fit. Don’t worry, no matter what you’ve done or how careful you measured, it will not fit right the first time. If your neck is a little wide, use a sanding block on the sides of the cavity to creep up to a snug, but not too tight a fit. Don’t sand the edges of the neck as it will screw up your fretboard width or make for some other weird transition. Remember to take a little off of each side to keep the neck centered. If you need a hammer to set the neck, it’s still too tight (and you’ll likely wedge both halves of the back body panel apart). If your fit is a little loose, some strategically placed shims glued into place will take up the slack (and no one will know). If you’re off by more than 2mm, you messed up somewhere. That large a gap (yeah, even 2mm) is telling you that something wasn’t laid out correctly (it’s really telling you that you’re a hack and shouldn’t be building a guitar in the first place!). Go back and check all of your measurements. You might have to go back to the start if you screwed up too badly. Once your neck slides smoothly into position with only minor friction, sand the portion where the neck penetrates the back body panel perfectly flush. Now it’s time to cut the end of the fretboard to it’s exact position. Check your distance from nut to bridge. Hopefully you’ll be right on or very close. The end of our fretboard abuts the neck pickup’s cover plate. I marked the exact location on the neck and made the cut with my trusty Japanese pull-saw. I cleaned up the corner with chisels and sandpaper. Be sure to spend plenty of time getting the neck accurate and true. This is the most important part of the instrument and will directly affect the playability and intonation of the guitar.