Build an Electric Guitar – Part 2
In this second of a two-part series, we take a look at how the neck is made, the fret work is completed and, finally, how to apply a finish to this beautiful instrument.
The neck blank needs to be 21mm thick and approximately 4″ x 30″. The length and width may vary depending on your headstock design. Draw a centerline the length of the neck blank. Lay out your neck template, center it and clamp it in place. Drill the index holes 7mm deep with a 1/4″ brad point drill bit. With the neck template still in place, trace the neck profile onto the work piece.
Build a Simple Jig
This jig will guide the router over the centerline of the neck blank to machine the groove that houses the truss rod.
A flush trim bit in the router table will trim the neck to its final shape and size.
For looks and comfort, a smooth transition between the heel and headstock is important. You have a choice of hand tools, power tools or a combination.
Accuracy Is Important
Drill index holes with a drill press to be sure they are perpendicular to the surface.
Indexing the Fingerboard
Toggle clamps hold the fingerboard in place for drilling.
Re-sawing the Headstock
With a bandsaw remove the waste from the headstock
Smooth and Scallop
With a stationary belt sander smooth the bandsaw marks and scallop the headstock. Be sure not to sand past the nut edge.
To level the fingerboard, and to level and dress the frets, this fixture which supports the neck will be indispensable.
Install the Frets
Being careful not to damage the frets or the fingerboard, use a hammer to tap the frets into place.
Fine tune the Frets
After the cyanoacrylate adhesive has hardened trim the frets and sand them to a 30° angle.
Re-crown the Frets
Use a sanding block with 400 grit sandpaper to re-crown the frets.
A String Tree May be Necessary
A string tree will create more downward angle on the strings behind the nut. It will prevent the strings from popping out of the nut while playing.
Set the Bridge
Some final adjustments will fine-tune the position of the strings.
Truss rod slot
To rout the truss rod slot, I suggest building a simple jig to hold the neck in position and guide the router.
Draw a centerline on a 34″ x 8″ piece of MDF.
On your neck blank, measure out and drill a set of through holes on center, outside of the neck profile. Pins will be used in these holes to center the neck on the jig and hold it in place for routing. Drill a corresponding set of holes on the centerline of the MDF jig.
Measure the width of your router base. Mount two straight rails to the jig, spaced accordingly, so your router will be captured in the space between the two rails. These will guide the router down the center of the neck while you rout the slot. Rails must be at least 1/4″ thicker than the neck blank.
Measure the length of your truss rod and mark start/stop points for routing on the neck blank. Rout the slot about 3/4″ longer than the rod, past the nut into the headstock. This will provide a recess for the wrench to adjust the rod. Pin the neck onto the jig so it is secure enough to rout the slot. Set the depth of cut on your router, then rout the slot in two or three passes. Different truss rods will have different dimensions, so size of bit and depth of cut will vary. I recommend using the two-way Hot Rods from Stewart MacDonald for this project. They are easy to install and allow you complete control over the neck. Follow the installation instructions provided by the manufacturer.
Mark your tuner layout on the face of the headstock. My tuner layout for a three-per-side headstock is as follows. The E string tuners are spaced 1-3/4″ apart on center, the next two are 1-1/4″ on center, and the top two are 1″ apart on center. The distance from the nut to the E string tuners is 1-3/4″ to the center of the hole. From there, they are evenly spaced 1-1/2″ on center, toward the tip of the headstock. Drill tuner holes with a brad point bit 1/64″ larger than the post of the tuning key, to allow for wood movement, and for ease of installation and alignment. Using a backer board, drill through until only the tip of the bit pokes through. Flip and drill through from the back side of the hole to prevent chipping.
Bandsaw the profile about 1/16″ oversize. Press the index pins through the template and into the neck. With the template secured to the neck, flush trim the last 1/16″ of the material off the neck. I use a 3/4″ flush trim bit mounted in the router table because I can maintain more control over the neck while machining.
Carving the neck
Begin by marking your heel and headstock transitions. You can either shape the neck on a belt sander or use a rasp or chisel to shape the heel and headstock transitions and a spoke shave for the shaft. The shaft should be no less than 14–15mm thick at the first fret and about 17–18mm at the 12th fret.
Indexing the Fingerboard
Draw a centerline on a 24″ x 6″ piece of MDF. Clamp your neck template to the MDF face down with the nut about 3/4″ from the end. Drill the index holes through with a 1/4″ brad point. Next, pin the neck template to the MDF and mark the nut position. The fingerboard will be aligned with the nut edge for indexing.
Mount two toggle clamps to hold the fingerboard in place for drilling.
For this project, I recommend using a pre-slotted and radiused fingerboard from Stewart MacDonald. Be sure to order a 24-3/4″ scale “Gibson-style” fingerboard, as all of the measurements given in this article are based on a 24-3/4″ scale Les Paul design.
Begin by confirming that at least one edge of your fingerboard is square with the nut edge. If it’s not square, trim the long edge so it is square. Don’t modify the nut edge in any way – this is a finished end. Once it is square, measure the width of the fingerboard. Draw a line parallel to the centerline of the jig, spaced half the width of the fingerboard from the center. This will be the reference line for centering the fingerboard on the jig.
Because the fingerboard is radiused, it needs to be shimmed until it sits flat, with its face down. Do this by placing an equal number of pieces of masking tape down each edge, on the face of the fingerboard.
To index the fingerboard, start by clamping a piece of MDF to the drill press table. This piece of MDF will allow you to add a referencing pin in the drill presses table surface. Install a 1/4″ straight cut router bit in the drill press and set the table about 2″ from the bottom of the bit. Because a router bit is made for use at high RPM, you should increase the speed of your drill press, and for good measure, plunge the bit slowly while you’re making the cut. With the table locked in place, drill a hole in the MDF table. Put a 1/4″ pin in the hole. It should be about 2mm proud of the table. Now you have a referencing pin accurately centered with the bit.
Clamp the fingerboard into the jig, carefully lining up with the nut edge and center reference lines. Place the jig on the drill press table with the pin in one of the index holes. Set the depth stop for 2mm, then drill both index holes in the fingerboard.
Glue the fingerboard to the neck
Pin the fingerboard to the neck to test fit. Remove the fingerboard and scuff the glue surface with 100g sandpaper. Install the truss rod according to the manufacturer’s instructions. Apply glue to the neck (I recommend G2 Epoxy, mixed three parts resin to two parts hardener). Keep the glue 1/2″ away from the nut edge to prevent squeeze out. Pin the fingerboard in place and clamp for 24 hours. When the epoxy is completely dry, bandsaw the excess finger board and sand flush with the neck. Be very careful not to re-size the neck.
Fret position markers
For the side dots, mark the center of the 3rd, 5th, 7th, 9th, 12th, 15th, 17th, 19th and 21st frets on the glue line. Space the double dots at the 12th fret equally from the center mark. With a brad point, bit the size of your side dot material drill about 2mm deep. Use five-minute epoxy to install the dots. After an hour or so, sand them flush. Top dots are optional.
Scalloping the Headstock
Begin by re-sawing the headstock to 15.5-16mm. It’s important to stop cutting when you get to the E-string tuner hole and very carefully back out. Make a short perpendicular cut to remove the waste from the front of the headstock. Use a stationary belt sander to remove the bandsaw marks. The round end of the belt sander will create the scallop. The scallop should come right up to the nut edge. Be careful not to sand too far. There should still be a 3-1/4″ flat spot where the nut will sit. Use the nut to check periodically while sanding. The final thickness of the headstock is 15mm.
The neck must be angled back from the body about four degrees. Use a stationary belt sander to sand this angle into the bottom of the heel.
Neck work jig
To level the fingerboard and to level and dress the frets, you’ll need to build a fixture to hold and support the neck while you work on it. The aluminum pieces pictured can be substituted with hardwood. Use 1/4-20 bolts for heel and headstock supports. The center support is a pin with a spring under it and a set screw to lock it in position. The neck is locked in with the cam clamp.
Level the fingerboard
Be sure that the set screw on the center neck support is loose. Place the neck in the jig and tighten the cam clamp. Begin by checking the fingerboard with a straight edge. If necessary, adjust the truss rod to correct any curve in the fingerboard. Tighten the set screw on the center neck support.
Mark up the fingerboard with pencil lines. With a 12″ radius sanding block and 220g stick-it (Stewart MacDonald), sand until all of the pencil lines have been removed and the fingerboard is true.
Maple fingerboards need to be finished with a lacquer or urethane clear coat before fretting. If left unfinished, maple will quickly become dirty and stained with frequent playing. Darker woods can be left unfinished.
The best way to install frets is with an arbour press. However, many of you will likely not have one. A bench vise with wooden cauls could be used as a press or you may hammer them in place.
First the fret wire must be bent to the radius of the fingerboard and then cleaned with Acetone, as it’s coated with a thin layer of oil. It will be much easier to radius and clean the entire length of fret wire before cutting it up.
Hold the fret in the slot and gently tap it in at each end. Press the fret until it is entirely seated but not denting the fingerboard. If you don’t have a press, hammer along the length of the fret until it is completely seated. Be sure the neck is firmly supported while hammering or pressing and be careful not to dent the fret or fingerboard while hammering. Trim the fret flush with the fingerboard. Once all the frets have been installed, put three drops of thin cyanoacrylate adhesive down each fret slot end. Do one side, allow the glue to cure for about 10 minutes, then flip the neck over and repeat on the other side. When the glue is set flush up the fret ends on the belt sander at a 30° angle.
Sand the neck from 180-grit up to 600-grit. When sanding at 220-grit, fill the fret slot ends by lightly sanding the edge of the fingerboard until the fret slot ends fill with dust. Apply a small drop of thin cyanoacrylate adhesive to each slot end. Repeat this two or three times until the fret slot ends are completely filled.
Avoid over sanding the heel of the neck. It’s critical that it fits tightly into the pocket to make a good glue joint.
Control Cavity Cover
You will need to make a cover plate to cover the control cavity. Trace your cover plate recess template onto a piece of matching or contrasting hardwood that has been machined to 0.5mm less than the finished depth of the recess in the body. Bandsaw the cover plate, then sand it to fit on a disc sander. Lay out and drill four or five 1/8″ holes for mounting. They should be 3/16″ from the edge on center. Countersink them so that the screw heads will be flush when mounted. Finish up by sanding the plate to 400g and finish in the same manner as described for the body and neck.
For this article I will be doing a natural oiled/hand-rubbed polyurethane finish.
You may choose to stain or dye the body and do a clear coat if you wish. Before applying any finish, mask off the portion of the heel that will be glued into the neck. Mask off the neck pocket in the body as well.
I recommend a first coat of Tung Oil as a sealer. Apply a generous coat of oil with a foam brush, let it soak for about five minutes then wipe the surface dry with paper towel. If the oil is left too long it becomes too sticky to wipe off, so you may want to wet your cloth with a bit of fresh oil and wipe it clean. Be sure to clean the fingerboard very well (clean maple fingerboards with mineral spirits) making sure there is no finish build-up along the frets.
After the Tung oil has cured for at least 24 hours, follow with six coats of Lee Valley Gel Finish. This is a two-day process. First, the body and neck need to be scuffed with #0000 steel wool. Apply the Gel Finish with a quartered section of a disposable dishcloth found at most grocery stores. Rub out along the grain until you have removed any streaks. Let cure for at least four hours before recoating.
Apply three coats the first day, then scuff again with #0000 steel wool before applying the last three coats on day two.
Level and re-crown the frets
If you’re using maple, the fingerboard needs to be masked off between the frets before levelling can take place. Follow the same set up procedure as for leveling the fingerboard. Once the neck is straight and the neck support is tight, mark the tops of the frets with a black marker. This will help you to see when the frets are perfectly level. With 320g stick-it on the same block you used to level the fingerboard, lightly sand the frets, taking long strokes the length of the neck, until the marker has been removed from the top of the frets. Take as little material as possible. The frets now have to be re-crowned. This is done by sanding over them (in line with the neck) with a piece of 400-grit wrapped around your index and middle finger. Use the same technique to soften the ends of the frets. Next, with a piece of 600-grit and a cork-faced or dense foam block, lightly sand in line with the frets to remove the perpendicular 400g scratches. This will make for smooth string bending. Finish by polishing the frets with #0000 steel wool.
Installing the nut
Nut files are a costly investment but they work well if you’re planning on mass-producing guitars. Without a nut file you’ll need to get the nut as close to the right height as possible before gluing it in. Measure the height of your first fret with callipers or feeler gauges. Sand down the bottom of the nut until the string slots are about 0.005″ higher than the first fret. Glue the nut in with medium cyanoacrylate adhesive.
Setting the neck
Mask off the body around the neck pocket. Place the neck in the pocket and tape off the neck where it meets the body. Scuff the neck tenon and the pocket with 100g. Be careful not to make the joint too sloppy. You should have, at most, a paper thin gap on each side of the neck. Apply G2 epoxy mixed 3:2 to the pocket and neck. Set the neck into position and clamp with a quick grip or C-clamp (not too tight, about 30 psi). Be sure to protect the neck and body from the clamp to avoid any clamping marks. Clean up the squeeze out with paper towel and methyl hydrate. Wait 20 minutes, wipe again and remove the masking tape. After an hour, check for further squeeze out and clean up if necessary. Clamp for 24 hours and wait 48 hours before further work.
Begin by installing the bushings for the bridge and tailpiece. This is best done with an arbour press or using a steel dowel in the drill press. They can also be seated carefully with a wooden, rubber or plastic faced hammer. Next, install the strap buttons. Now it’s time for tuners. Begin by placing the two E-string tuners into their holes and finger tighten the nuts. Use a straight edge to perfectly align the tuners so their top edges are parallel. Tighten the nuts enough to hold the tuners in place, double-check they are still aligned, then drill a 1-1/4″ pilot hole for the set screws. Mount the rest of the tuners the same way, then install the set screws, check alignment once more and firmly tighten the nuts. Before installing any of the electronics, I recommend shielding the control cavity and back side of the cavity cover with adhesive shielding foil from Stewart MacDonald. This will eliminate most of the unwanted noise or hum that is associated with electric guitars. Now mount the pots and switches. Mount the jack to the jack plate and hold it in place to mark the screw holes. Drill pilot holes for the jack plate screws. You’ll want to wait until you have the wires soldered to the jack before screwing it on, otherwise you won’t be able to access it to solder.
Now you can install the pick-ups, wire the guitar and mount the jack. Excellent wiring diagrams for any configuration can be found online. Next, mount the bridge and tailpiece. Use a piece of tape to hold the tailpiece in place while you get the first couple strings on, as it is held in place only by string tension. Finish by installing control knobs and the cavity cover. You may also need to add a string tree to create more downward angle on the strings behind the nut so they won’t pop out of the nut when you bend a string.
Set up and Final Adjustments
With an accurate ruler, roughly set the bridge so that the strings are about ⅛” above the frets on the bass side and 1/16″ on the treble side.
Plug in! Tune the guitar to pitch. Now the truss rod can be set. To do this, fret the D string at the first fret with your left hand and at the 17th fret with your right pinkie finger. Now use your right thumb to tap the string at the 7th fret (if you don’t have the reach for this, use a capo on the 1st fret). There should be a 0.01″ gap between the string and the top of the fret. This is called relief. Adjust the truss rod to achieve approx. 0.01″ relief. Now the string height can be fine tuned. Measured at the 15th fret, the low E string should be at 1/8″ and the high E string should be right on the 1/16″ mark. This is fairly low action. You may need to raise it later if there are string buzzes, or you prefer higher action. Next is intonation. Compare the 12th fret harmonic with the fretted note at the 12th fret. If the harmonic is higher than the fretted note, the string needs to be shortened. If the fretted note is higher than the harmonic, the string needs to be lengthened. Adjust the bridge saddle accordingly. Do this for every string. You are now ready to rock your new guitar!