Build a Box Guitar
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This article is from Issue 85 of Woodcraft Magazine.
Tune up your woodworking skills with a project that will bring enjoyment for years to come.
Cigar box guitars have been around for a long time; the earliest versions date back to the Civil War era. Two centuries haven’t diminished the appeal of this homespun instrument. Though a box guitar won’t have the same acoustic properties as a standard version, it provides just the same playability, in a compact, rugged package. Building your own version is a great way to get started as a luthier.
I began making box guitars with high school students in my shop class several years ago. Rather than depend on a ready supply of cigar boxes for these guitars, I decided to put my box-making skills to good use. Although the box I’m building here is a basic rectangle with finger-joint corners, other joinery details and box shapes are also possible. The goal remains the same: Have as much fun making your guitar as you’ll have playing it.
Let’s get started!
Well-made parts and luthier supplies make wood sound good
You don’t have to be a guitar player to make a fine box guitar, but it helps to familiarize yourself with the key parts of this stringed instrument. Clear, straight-grained spruce and cedar are good woods to use for the top of the guitar. I like to use hardwood for the remaining parts.
Order of Work
- Build the box frame.
- Make and attach the back to the box.
- Make the neck.
- Cut fret slots and install the frets.
- Attach the neck to the box.
- Install tuning machines, then make and install the bridge, nut, and tailpiece.
- String up and play.
Special tools and materials. Basic woodworking tools will handle many aspects of box guitar construction. But you’ll also need some special items, which are available from dealers who specialize in luthier supplies (see Buyer’s Guide, p. 68).
Build a box frame with finger joints
Finger joints are strong and attractive—a fine choice for box guitars and other woodworking projects. While some box joint jigs are designed to cut fingers and sockets of different sizes, mine is set up for a single size: 3/8". Make sure to test your jig on some scrap stock before you use it to make the guitar’s box frame.
How to make & use the Jig
- Rout runner dadoes in a single workpiece from which the base and sled can be cut. Then rout the dado for the fence.
- Cut the dadoed workpiece apart to create the base and sled. Then cut and install the hardwood runners.
- Drill a 11⁄2"-dia. hole in the base to provide clearance for the router collet, then screw the router base to the underside of the jig’s base. Outfit the router with a 3⁄8" straight upcut bit.
- By raising the bit in 1⁄8" increments, and sliding the sled on the base, rout a 1-3"-long slot in the sled.
- Screw a stop block to the base to stop the sled when the bit will be housed in the fence.
- Position the fence in its dado so you can rout a slot for the key. Then slide the fence over so the key is 3⁄8" from the slot in the sled.
- Clamp the jig to the edge of a workbench, and cut some test joints. If necessary, fine-tune the position of the fence (and key) until you get finger joints that fit snugly without being forced.
- Screw the fence to the sled when the fit is right.
Pins first, then sockets. Two facing sides will begin with pins. Butt a side against the key, rout the first pin, then straddle the key to rout remaining pins. To rout a socket side, butt the side against a completed pin to set up the first socket cut, then complete the straddle-and-cut sequence (left). When assembling the box frame, take time to spread glue thoroughly on the joints (above), and make sure the frame is square.
Now add blocking and a book-matched back
Once the box frame is together and the exterior has been sanded smooth, it’s time to add two more parts. Gluing solid hardwood blocking to the box interior where the neck will be attached ensures a strong neck connection. The book-matched back is a traditional luthier’s detail that adds beauty to the back of the guitar.
Blocking for the neck. Glue a 3⁄4"-thick maple block to the inside of the box where the neck will attach. The top edge of your blocking board should be flush with the top edge of the box.
A book-matched back. After planing boards to a thickness of around 3⁄16", glue up the back, orienting the boards to create the best book-match. When the glue dries, plane the back slightly thinner, and glue a backing strip over the seam.
Too many clamps? Using fewer clamps and some clamping cauls to distribute pressure will work just as well here. Note the 1⁄8"-thick, 3⁄4"-wide backing strip glued in place over the book-match joint before gluing the back to the sides.
Flush-trim the back. After the glue dries, I use a flush-trim bit in the router table to trim the bottom flush with the sides.
The neck needs a graceful shape...
The neck starts out as a straight length of hard maple that gets blocking glued to each end. Building up the thickness at each end gives a stronger connection where the neck joins the box, and allows the peg head to be angled back, keeping the strings in tension against the nut. The drawings below provide the details for making the neck blank and then cutting and shaping it to final size. Before cutting any tapers on the bandsaw, make sure that the end of the neck (which joins the box) is cut perfectly square. Once the rough shape of the neck is cut, take your time with final shaping and smoothing, because you’ll want this part of the guitar to be comfortable to hold.
A blank with blocking. Start with a dead flat neck blank 7⁄8" thick, 23⁄4" wide, and 25" long. Then thicken each end of the neck blank by gluing blocking in place as shown.
Rough out the shape. After drawing the tapered layout on the neck blank, cut the neck to rough size. Stay slightly outside the lines.
Shape, then smooth. I use a rasp to refine the shape of the neck. Fair the neck’s curve by eye, but also test your progress by feel. When shaping is done, smooth by sanding to 220-grit.
...and precisely spaced frets.
Fret wire has a T-shaped profile with tiny barbs that keep frets locked in kerfs made with a fret saw. Once you’ve finished installing the frets, take extra care in screwing the neck to the box. Clamp the neck in a vise as shown below.
Accurate layout. With an inexpensive fret template, you can precisely lay out frets without measuring. Align the template over a centerline on the neck, then mark the nut and fret slots with a sharp pencil.
Saw the slots. Clamp a guide block on each fret’s layout line to keep the saw vertical as you cut. Adjust the fret saw’s depth gauge to match the fret wire's barbed flange.
Seat, snip, and file. Allow each fret to extend beyond the neck sides when you install it, seat the fret with a hardwood block, to avoid damaging it with a hammer. Then snip the fret just proud of the sides with wire snips. Use a fine-cutting metal file to get fret ends flush with neck sides, then gently round the ends over so they're smooth to the touch.
Connect the neck. Lay out a triangular pattern for drilling pilot holes in the neck and the box for three #10 × 3" screws. Layout and drill each set of holes so the neck will be centered on the box, with the fingerboard 1⁄4" above the box side where it’s attached. With the neck clamped in a vise, I place a washer beneath each screw head, and use a ratchet-type driver to torque down the connection.
Good progress! Now let’s work on the top...
Good sound depends on good wood. Luthiers often use Western cedar for guitar tops, and I found some at my local lumber yard—with enough thickness to resaw, glue up, and plane to make a good top. Look for clear stock with closely spaced growth rings; this tells you that the wood has taken longer to grow and will give a more vibrant tone. Plan on making a top piece 1/4"-3/8" larger than the outside dimensions of your box, so it can be flush-trimmed after installation. After gluing up two book-matched boards, plane and sand the top to about 1/8" thick.
Glue the top to the box. Spread glue on the top edges of the box and press the top in place. Instead of using several clamping blocks, I simply placed a single piece of 1⁄8" plywood over the top before putting clamps in place. Trim the edges flush at the router table as before.
...and install the tuning machines and nut.
Tuning machines vary in size and design, so it’s best to have yours in hand before you begin building the guitar neck. This will enable you to make sure that holes for pegs are sized and spaced correctly. Select a drill bit that matches your peg diameter.
Make the nut from a hard, durable wood like persimmon (which I used here) or ebony. Synthetic ivory (available from luthier suppliers) is also a good choice.
Perfect holes for peg heads. To avoid tearout, I mark the hole centers and drill them out with a 1⁄8"-dia. bit. Then I drill in from both sides with a full-size bit, guided by the smaller holes.
Chisel out the nut slot. The nut’s location is marked when laying out the frets. The width and depth of the nut slot is defined by a pair of parallel saw kerfs. I use a 1⁄8" chisel to remove the waste and create a flat recess for the nut.
Aim for a firm fit. I made the nut from persimmon, the only North American member of the ebony family. Cut the nut a hair oversize, then sand it for a tight fit, so it can be adjusted or replaced.
Tiny screws for tuning machines. Drill pilot holes that extend the full length of the screw shank. This will prevent stripping or breaking these tiny fasteners.
Get set for strings, then start to play!
Before tackling these final construction steps, treat your guitar to some finish. My preference is to apply several coats of wiping varnish. Once the finish is dry, it’s time to focus on how to anchor the strings to the base of the guitar, support them an appropriate distance from the nut, and put them at a uniform height above the neck (action). As you complete this final work, keep in mind that the action is important. Too high, and it’s difficult to push strings down against the fingerboard. Too low, and the strings will buzz against the frets. Since the nut and the saddle are responsible for holding the strings, action adjustments are made by raising or lowering these two parts.
Punch, then drill. Follow the layout to mark hole centers, then use a metal punch to make a recess that will guide your drill bit. After drilling holes, you can personalize your guitar by using metal stamps on the tailpiece.
Use a vise to bend the metal. Put a near-90° angle where the tailpiece folds from the end to the front of the guitar. Then make an additional slight bend along the string holes to provide clearance underneath for the ball ends of the strings to fit.
Install the tailpiece. Use a straightedge to align the tailpiece with the fingerboard. Painter’s masking tape can mark the location as you drill pilot holes for three installation screws. Drive these through the tailpiece holes and into the box bottom.
Glue down the bridge. Proper tone depends on the correct distance between the saddle and the nut—243⁄4" for the template I’m using. String up the guitar, position the bridge as shown, and mark its outline with tape. Then loosen the strings and scuff the top where the bridge will fit using 220-grit sandpaper. Spread glue on the underside of the bridge, position it on the top, and tighten the strings to keep it in place as the glue dries. Great job! Now you can start strummin’.
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