The one piece
guitar build.

The short version

A one-piece guitar has the neck and body cut from a single board. No neck joint, no glue line, nothing to come apart.

The build itself isn't much different from any other guitar. What's different is that nothing can be replaced. Ruin the neck on a bolt on and you make another neck. Ruin the neck here and the whole board is firewood, and boards this size are hard to find and expensive.

The numbers, in one place

Dimension	Figure	Note
Board thickness	1 3/4″	Standard body thickness
Finished neck depth	3/4″ to 7/8″	Most of the board's depth under the neck is removed
Rough cut margin	3/16″ all round	Leaves room if the blank moves during the second cure
Bandsaw beforerouteing	Within 1/8″ of the line
Pickup cavity depth	3/4″
Neck back angle	~3/16″ of drop	7/8″ at the nut rising to 1 1/16″ at the neck pickup
Truss rod channel	~3/8″ deep	Measure your own rod
Roundover	1/4″	Top and back
Headstock counterbore	3/4″ Forstner	So the tuner nut reaches its threads
Electronics cavity floor	~1/8″	Thicker and the blade switch fouls. Thinner and it cracks.
Cavity cover ledge	~1/4″ wide, 1/8″ deep	Rabbet bit with a reduced bearing
Output jack	5/8″ Forstner 1/8″ deep, then 1/2″ through
Bridge position	25 5/8″ on a 25 1/2″ scale	See the bridge section, this one matters
Moisture meter	Cheap	10 to 15% or under is workable

The hardest part is finding the wood

Not the building. Finding a board wide enough.

Hardwood suppliers used to carry a decent selection of very wide stock. Since the economic downturn of the early 2000s, most of them no longer do, and genuinely wide boards have become difficult to source and expensive when you find them.

Once you've found something wide enough, it still has to be the right board.

Reading the board

Straight grain first. Grain that wanders across the board in odd directions is a bad sign. It doesn't have to be perfect, wavy is fine, but it should run broadly straight down the length, and you should lay the guitar out following it.

Density has to be consistent across the width

This one is less obvious than grain direction and matters just as much.

Wood near the core of a tree often differs from wood further out, in color, and frequently in density. On this Korina board that shows as the dark black limba nearer the core and the pale white limba further out. Same tree, different properties.

Look for consistency across the full width. A board that is porous and pale at one edge and dense and dark at the other is one to leave behind.

When a defect is acceptable

The board I used here has what's nearly a knot, sitting in the neck area, normally a reason to reject it outright. I used it anyway, for a specific reason:

The board is 1 3/4″ thick. The neck only ends up 3/4″ to 7/8″ deep. Almost an inch of material under the neck gets removed during shaping, and the defect sits in the part that disappears.

Knowing where the wood goes is what lets you use a board that looks marginal. The same logic applies to the headstock, which doesn't extend to the full depth either.

The remaining grain irregularity ends up visible on the back of the finished neck, where it reads as an attractive pattern rather than a flaw. Customers like it.

Shifting the layout to dodge problems

If a flaw sits where you cannot accept it, try moving the template. Slide it along, or rotate it slightly, so the neck misses the problem area.

On this build I positioned the template to satisfy two things at once: dodging the worst of the defect, and centring the black to white color transition in the body, because that fade is what the customer is paying for.

Curing. And why a one piece needs two stages

This is the part that decides whether the guitar survives, and it's the part people skip.

Judging moisture

• The board should feel light for its size. Heavy for its size means water still in it
• A moisture meter is cheap, two probes pushed into the wood. 10 to 15% or below is workable
• Push the probes somewhere that will never be seen. The holes are small and permanent

The Korina board here had sat in the shop for eight or nine months before use.

The two stage cure

This is specific to one piece builds and it's why they take longer.

1. The solid state cure. The board dries as a whole, which can take months. Sometimes you buy it already cured.
2. The rough cut cure. Cut the shape out oversize, then test the moisture on the freshly cut faces. The inside of a thick board stays wetter than the outside for a long time, and until you cut it you can't know.

If that second reading comes back high, the blank goes back on the shelf for a few weeks and gets tested again.

A useful check on any meter: it reads almost nothing on a properly cured board, then jumps immediately when the same spot is sprayed with glass cleaner. It genuinely is reading moisture, not guessing.

Reading internal tension at the bandsaw

Cutting the blank tells you things the meter can't. Watch the kerf behind the blade.

• If the cut closes up behind you, narrower than the blade left it, the wood is pulling in that direction
• If the blade wants to veer off line, same conclusion

That's internal tension: stress in the wood from grain pattern, from moisture, or from how it was sawn.

What a one piece actually gives you

Worth being straight about, because it's oversold everywhere else.

What does change is dynamics:

• The harmonics behave a little differently
• The attack is different
• Sustain is dramatically different

That's a real, repeatable difference, and it's not the same claim as "it sounds better".

Layout

Find and mark the centerline first, with a metal yardstick. Everything references it, and on a one piece it has to run through both the body and the neck as a single line.

Position the template, mark round it leaving 3/16″ or more all round, and bandsaw the rough blank out.

The offcuts from a board this size are worth keeping. There's usually enough left over for a complete conventional body.

Routing the outline

Bandsaw to within 1/8″ of the final line first. Consistently. Too much material left and the router works hard and chips out; too little and you lose your margin.

Then double-sided tape the template on, lining its center to the blank's centerline, and check it before you switch anything on.

The bit

Half inch collet, bearing on top to follow the template.

Turn the speed down. Larger bit, slower speed, the wrong combination gives you chip out, burning and dull cutters.

Technique

• Start where there's no wood, an area already cut away. So the bit enters gradually instead of slamming into a full edge
• Press against the template hard enough to keep the bearing on it, but not so hard you're tipping the workpiece
• Change the guitar's position regularly so you always have proper control, rather than reaching awkwardly

Trouble spots, every time: the horns, tight curves, and the tip of the headstock, anywhere you're cutting end grain or turning sharply. On this build the headstock tip was worked very slowly, and the fallback if it starts to kick is to leave it and shape that curve with a sander instead.

Cavities

With the template still on, rout the pickup cavities: 1/2″ template bit, plunge router, higher speed for the smaller bit, 3/4″ deep, clearing chips between passes.

The neck back angle

Without a back angle, the neck comes out level with the body and the strings sit barely above the fretboard, leaving you no choice but to recess the bridge into the body.

The numbers from this build:

• About 7/8″ of thickness at the nut
• About 1 1/16″ where the neck pickup sits
• A difference of roughly 3/16″. And that's more than enough

Cutting it

The jig is a piece of MDF cut at the angle you want, clamped alongside the neck. The router rides across the top of it, so the surface it cuts comes out angled instead of flat.

1. Clamp the jig so nothing can shift
2. Run a straightedge down the side and mark where to stop, you only want to cut where the fretboard sits, not into the body
3. Set the bit height to the low end of the angle
4. Run it, then check for flat spots and take a second pass about 1/16″ lower if needed

The truss rod channel

Another jig: one the router sits inside tightly, holding it centerd and stopping it wandering.

• Depth to suit your rod. Nearly 3/8″ here
• Do test cuts at the top end and check with calipers before committing to the length
• Know where to stop. On this guitar the rod is adjusted through the neck pickup cavity, so the channel ends there

Test fit the rod. A 64th too shallow in one or two spots is not a problem: deepen just those areas with a chisel so the rod beds down and can't rattle.

You'll also need to widen the channel where the adjusting nut and the soldered joint sit, on this rod, an extra 1/4″ on each side of that section.

The fretboard

Fitting it

Tape the fretboard down and center it at both ends. You get one shot, so check, check again, then mark round the overhang from underneath.

Bandsaw about 1/16″ outside that line, then take it to final on the jointer in small increments until it sits flush against the neck.

Radius it before gluing

Radiusing off the guitar is faster and more accurate than working on a glued up neck, and it takes care of levelling the inlay at the same time.

Order: radius → side dots → glue.

Gluing

I use ordinary Titebond. Epoxy is used by some makers, PRS among them, and it isn't necessary.

Enough glue for full coverage, not so much that you have a flood to clean up.

Clamping

• Use radius blocks as cauls across the fretboard. Clamp directly onto a thin board and it cups upward between clamps, leaving a poor joint
• Clamp the whole assembly down to a flat surface as well
• Start at one end and work along in one direction
• Watch down the side for a tight seal and for any shifting
• You want glue visible along the whole seam

Scrape the squeeze out at the nut end while it's soft. Anything left there gets in the way when you come to cut the nut.

Roundover, armrest and belly cut

Where the template overhung the board slightly, sand a gentle curve into both sides to match. Use the template itself, flexed to the curve you want, to draw a matching line on each side.

Belt sander for the armrest and the belly cut, then a 1/4″ roundover across the top and back.

Mark where to stop first, so the roundover doesn't run into the neck.

The neck profile, the hard part

This is where a one piece stops resembling a normal build. On a separate neck you can hold it, turn it, and get at every surface. Here it's attached to a body that's in the way of everything.

Start by bandsawing away as much waste as you can reach, the upper horn will stop you going far.

Two problems with routing the profile

Problem one: the back angle. Because the neck now sits at an angle, running it flat across a router table would cut the headstock end much thinner than the heel end.

Fix: a 1/4″ spacer taped under the headstock to level the neck out. The result isn't perfectly even, but it's close enough that the remaining difference is easy to work out by hand.

Problem two: what does the bearing run on? The fretboard is too narrow and too shallow, the bit would cut into its edges.

Fix: a template taped on top of the fretboard, slightly wider than the fretboard itself. Three benefits at once:

• The bearing rides on the template instead of the fretboard
• Its curved ends give a gradual transition into the neck instead of an abrupt stop
• It provides handles, keeping your hands away from a large exposed bit

Low speed, both sides, using your marked reference line for the bit height.

The heel transition, by hand

The router can't reach into the area where the neck meets the body. That's a chisel and hammer job, and it looks brutal.

Then draw knife, then belt sander, then finer sanding. Expect around 25 to 30 minutes of shaping just for this transition.

If you don't have a router table, none of this is a barrier, a wood rasp and a draw knife or spoke shave will shape a neck perfectly well. The router is faster and more consistent, not essential.

Judge it by feel

Knock down any sharp edges by hand as you go. Sharp edges are where chipping and splintering start, and a soft transition simply looks better.

The headstock

I make headstocks here deliberately thick. They don't break, and the extra mass adds a little sustain.

1. Clamp the template on and check nothing can shift
2. Mark the hole centers with a punch. A sharpened, centerd nail in a guide gives a dimple for the drill bit to find
3. Counterbore with a Forstner bit, 3/4″ here, to the depth needed for the tuner nut to reach its threads. Without this the nut won't tighten. The depth depends on your washer thickness
4. Drill through with a backing board underneath

The electronics cavity

Same method as the pickup cavities, just deeper. Stop with about 1/8″ of material remaining.

For the cover ledge, use a rabbet bit with a smaller bearing fitted than the one it came with, that gives a narrower rebate, around 1/4″ wide, at whatever depth your cover material needs. About 1/8″ here.

Test pass first and adjust the depth before committing.

Route the cavity generously while you're there. Extra room costs nothing now and means a kill switch or extra electronics can be added later with nothing more than a couple of holes.

Wire holes and the output jack

• Not a drill press, this is freehand, at an angle
• Clamp the guitar down for control
• Keep as level as you can, aiming for the bottom of the cavity, and watch you don't break through anywhere visible

If the guitar has a middle pickup, drill its wireroutee before the fretboard goes on, while you can still come at it from the other direction.

For the jack: 5/8″ Forstner about 1/8″ deep for the plate recess, then swap to a 1/2″ bit and go through for the barrel. The starter hole keeps the second bit centerd.

Where the bridge goes

This is the measurement people get wrong, and the mistake isn't recoverable without moving mounting holes.

Why the extra eighth

Fretting a string stretches it slightly, which pushes the note sharp. The saddle has to sit a little further back to cancel that out, and thicker, stiffer strings need more of it, so the low E always ends up furthest back.

An eighth of an inch is 3.2 mm, right in the normal range for a wound low E. Marking at 25 5/8″ puts the bridge where the low E actually needs to be, leaving every other saddle room to move forward from there.

The sequence

1. Set the low E saddle to the middle of its travel first
2. Then position the whole bridge so your 25 5/8″ mark falls at the center of that saddle
3. Shuffle forward and back until it lands exactly

That leaves you roughly an eighth of an inch of adjustment in both directions when you come to intonate properly.

Checking it's square

Two things should sit on your centerline: the center mounting hole at the rear, and the center point between the saddles at the front. Get both and the bridge generally squares itself.

And this is what the back angle bought you

With the back angle cut, the distance from the fretboard surface up to the body at the bridge is around 3/8″. Add fret height, at least 1/8″. Plus your action, and you're a little over half an inch.

A typical hardtail bridge stands 3/8″ to 1/2″ tall. So the numbers work, and the bridge sits on the surface. Without the back angle it would all be too low, and the bridge would have to be recessed into the body.

What is left

From here it's the same as any other guitar, finish sanding, fretting, nut, finishing, electronics. Nothing about a one piece changes any of that.

By this point there are still three to three and a half hours of work left before the instrument is finished.