Next subject up for me to explain regards the various pockets and cavities you’ll need to form in the body. This is where a good plunge router really shines. However, as you might have guessed, there’s more to the story than router skills. In fact, most of the work will actually be done with a big Forstner bit.

The most important cavity in terms of critical dimensions is the neck pocket. Regardless of whether you’re making a bolt-on or set-in neck, you’ll need to form a pocket that the neck can sit in nice and snug. There should be no play or gaps and ideally, before you glue the two together, you should be able to lift the neck without the body falling off the heel. One might assume this is accomplished by having a good template, but that is not the best approach. In truth, the neck itself–specifically the heel tenon–should serve as a template. If you were to try and make a template from a plan, there’s a good chance it won’t match the neck’s heel tenon. That’s the nature of woodworking by hand. Even if you try to stick to the plan, sanding and shaping can slightly alter the tenon from the intended shape. Unless you’re using a CNC router to do the work, you’ll need to use the heel tenon in order to get the most accurate pocket shape.

In this photo, you see the guide boards in place around the pre-drilled neck pocket.

Here is the workflow I follow for making the neck pocket: Start by laying the neck on top of the body where it will ultimately sit. Make sure it’s straight with regards to the body’s centerline. It’s a good idea to clamp the neck in place so it won’t move around. Next, I trace a pencil line onto the body all the way around the tenon. To save wear and tear on my router, I like to pre-drill the pocket with a big Fostner bit in my drill press. Before I drill, I set the depth of the bit so it will only drill a hole that’s equal to the depth of the pocket. If I plan to angle the neck, I will either keep the bottom of the pocket flat and angle the bottom of the tenon, or I’ll keep the bottom of the tenon flat and angle the pocket. I like to keep the pocket flat because I can really fine tune the angle by sanding the tenon and testing the neck’s fit.

After drilling out the pocket (stay at least an 1/8″ [3mm] from the edge of the pocket), I clamp boards on both sides of the pencil line indicating the sides of the pocket. Then, I add another to butt up against the back line. Make sure the boards are right on top of the line so that when you rout, the pocket will be a shade smaller than it needs to be. All three are clamped (or attached with double-stick tape) in such a way that I can move the router around the pocket without hitting a clamp.

This is a pattern bit.

Before going any further, it’s important to make sure the boards are both level to the body and that they have edges straight edges. They will serve as a guide for the pattern bit you’ll be using in your router. Set your router’s depth so the bearing will contact the boards as you clean up the pocket’s sides. At the same time be aware of the depth When you get near the bottom, shut off the router before plunging the bit to the bottom. You don’t want to accidentally punch a hole in the bottom of the pocket!

When you’ve finished with the pocket, you’ll likely end up with rounded corners. The easiest way to deal with this is to round the corners of your neck’s heel. You could chisel them out, but only do this if you have the necessary skill.You’ll also notice (if you did the routing correctly) the pocket is slightly smaller than the tenon. To get the two to fit, sand the tenon and repeatedly test the fit. The goal is a snug fit. Not so tight that you really have to force it in (this could split the body!), but tight enough to hold them together when you lift the guitar off your work surface.

Now that's a good fit!

At this stage, you’ll be tempted to glue up the neck to the body, but DON”T! I’t easier to work with the body, sans the neck, while you form the pickup and control cavities. Speaking of the pickup and control cavities, let me move on.

The rule here is to use templates. Even if you have to make your own. However, I have found that purchasing templates can be cheaper than making your own, but everyone’s situation is different. If you have to make your own, do so as precisely as possible. Remember, the clearance between the edges of a humbucker pickup pocket and the trim ring is very small. If you make the pocket too big, the ring won’t cover it.

Forming the control cavities follows much of the same techniques as were used to make the pickup pockets. However, there are a few things you’ll need to consider first. If you plan to plunge the cavity from the front of the body, you’ll need to make sure it’s at least a 1/4″ (6mm) smaller than the pickguard that will cover it. If you plan to access the cavity from the back, you’ll have to decide how you’ll want the cover to fit over it. The easiest way is to make a cover that is at least 1/4″ (6mm) larger than the cavity so it sits against the back. However, I think this approach looks clunky. Instead, you’ll want to consider routing a recessed shelf all the way around the edge of the pocket that’s as deep as the cover’s thickness. That way the cover will sit flush with the body.

For a flush control cover, you'll need two templates.

Look closely and you can see a 1/4" (6mm) shelf, which will support the cover.

When routing a recess, you’ll need two templates. The first will be used to rout the inside edges of the pocket after it has been pre-drilled with a big Forstner bit. Make sure you know the depth of the pocket before you start drilling. The depth will be determined by how tall the threaded shaft is on your pots and switches. You’ll need to leave enough wood (no less that 1/8″ [3mm]) from the bottom of the cavity to the front of the body, so be sure the threaded shaft is long enough to go through the body while giving you enough threads to screw on the nut and washer.

Select a straight bit and a brass bushing that will work together for routing the recessed shelf.

The second template will be used to rout the recess.  Since a pattern bit is too long for routing the shelf, you’ll need a straight bit instead. In order to follow the template, with your router, it’ll need a baseplate fitted with a brass bushing with an hole that’s slightly bigger than the bit. This means the templet will have to be larger than the cover. Measure from the outside of the bushings guide shaft to the blade on the bit. That measurement with tell you how much larger all the way around the template will have to be. Before you start routing, set the bit’s depth so it equals the thickness of your cover.

Make sure the screws you use to attach the back won't run into any wiring tunnels!

If you go the flush cover route, you’ll need to plan on the size of the screws that will hold the cover in place as well as where they will be positioned. I typically use a fairly small diameter wood screw with a length of about 3/4″ (18mm) to do the job. At least 4 screws will be needed. Since you’ll be connecting the control cavity to the pickup pockets and the bridge by drilling 1/4″ (6mm) tunnels, be careful not to drill the cover mounting holes so they might enter one of these tunnels. The last thing you want to do is cut the wires with either the drill bit or the cover mounting screws!

To drill the wiring tunnels, you likely need a 1/4″ (6mm) drill bit that’s at least 12″ (305mm) long. Long bits will help you get the angle you need to drill from pocket to pocket. Before you drill, pay very close attention to both the direction and the angle. You don’t want the bit to miss it’s mark and dill out the other side of the body.

The last cavity I should mention really isn’t a cavity at all. It’s the output jack hole. I like to mount my jacks into the edge of the lower bout. I drill a 7/8″ (22mm) from the edge into the cavity. Since you’ll probably have to use a hand drill, try to position the cavity so it isn’t any more than an inch (25mm) from the edge of the body.

If you plan to use a Strat style jackplate, you’ll need a template to form the hole, especially if the control cavity is routed from the back. Also, since you’ll likely need to rout the hole with a straight bit and a brass bushing, the template will have to be oversized to accommodate the gap between the blade and the outside of the bushing’s guide shaft.

If any or all of this info seems confusing or way too much work, it really isn’t. Describing woodworking techniques on paper is always a tad difficult. To help you grasp these techniques, I recommend printing out this posting and keeping it close as you practice routing on some cheap/scrap wood. Once you’ve developed the confidence to make your own cavities, then attack the body.

In Part 11, I will endevor to enlighten you on the myriad of complexities regarding the selection and installation of an electric guitar bridge. Stay Tuned!