Guitar Build Process

Milling bulk stock in advance

Access Port

Tasmanian Oak, 2.5mm thickness
(Lengths to be steam-bent need to be 560mm, for simplicity's sake they can all be that)

Blackwood, 2mm thickness

Jarrah strips: 12x2mm

Neck Block

Tasmanian oak
(Lengths can be anything really)

* 90mm stock allows for backing plate to be 65 (Guitars) or 67 (Bass & 12-string)

Fingerboard support extension and tray

Tasmanian oak
(Lengths can be anything really)

(wider/thicker variants for Bass & 12-string)

Neck reinforcing spline

8 x 18mm (but best to wait until channel is routed)

Headstock Veneer

Celery-top Pine & dark*Blackwood: 110 x 2.4mm
Lengths: 210 (bass & 6-strings), 250 (12-strings)
Alternatively: dark Jarrah
* to allow for contrast with resin logo

Fingerboard

Spotted Gum, 66 x 6.5mm

Fancy fingerboard binding (optional, and only for glued-in neck option)

Lengths same as fingerboard

Understated fingerboard binding (optional, and suitable for bolt-on neck option)

* ideally, from same piece as fingerboard

Sides, back, soundboard

Best left to when they're needed so they don't warp or cup over time

Bracing

Tasmanian oak
Lengths: depends on guitar model

Kerfed lining

• King Billy Pine

• Radiata Pine (works ok, low rent)

• Macrocarpa (a bit splitty)

19 x 7mm, rounded over on one corner
Lengths: 800-900mm

Bindings

950(bass) x 9 (850/800 for guitars)
NB: all pieces must be the same height, for effective tape-clamping force
Simplest plan, may need refining

Layout:

Bridge blanks

Spotted Gum
10mm thickness
Bridge is approx 50x152, but larger for CNC router

Heel cap

Jarrah
10 x 60mm, length not important

Pickguard

Jarrah
70 x 2.5mm

Truss Rod Cover

Jarrah
55 x 3mm - though laminated is recommended

Access port cover and frame

For the cover, there will be six layers, in three pairs

• inner pair (smaller hole)

• middle pair (larger hole)

• outer pair (larger hole, outer layer Blackwood)

For the frame, there will initially be only four layers (two pairs)

• This is because the outer layer will be the sides of the guitar

• However, after the frame is fitted to the sides, two additional layers will be added

Resaw & mill tas oak stock into 2.5mm sheets
Do the same for a smaller amount of Blackwood for the outer, show layer

• mill this to 2mm, and also a vertical-grain backing layer - to equal thickness of guitar sides

Note that the measurements below are workpiece end-targets, leave stock a little wider so that trimming to final size can be done later.

All pieces 2.5mm thick
The 25mm is a minimum, 30 is OK

Cut bent stock into 560mm lengths & steam bend

moisten strips, then layer two at a time (for 25++mm widths, two lots side by side)
wrap in aluminium foil
heat with heat gun
place in mould, clamp for about 5 mins total
while still warm, swap ends over, re-clamp (try to even out any unevenness in curve)
when cool, remove from mould, remove aluminium foil,
hold lengths in long clamps while drying

Covers

Note that the outermost layer will actually be a little wider due to the "nested" nature of the lamination.
six layers, alternating grain, two "smaller", four "larger" (outer one Blackwood)
laminate in pairs, using bass mould and matching cauls for outer pairs, guitar mould for inner
for each pair, the outer layer of the curve has lengthwise grain from bent pieces, inner upright grain from flat.

The outer "show" layer, from 2mm boards, is a little different

• may well have both pieces lengthwise grain, as per guitar sides)

• we usually have aJarrah border on the outermost layer,

• in this case, we should wait until it is time to fit the outer layer into the guitar body

The border process is

• wait until it is time to fit the outer layer into the guitar body

• sand the the outer layer's inner ply to fit

• cut the center piece from blackwood, leaving space for border around side

• using centre piece to balance vertically, glue in centre piece, top and bottom

• glue the side pillars

Trim to dimension/tidiness using belt sander
Then laminate two pairs - inner and middle - together:

• check curvature of laminating mould against solera mould, with any neck-join shimming in place

• tack together with thin nails for alignment,

• optional: place nails such that we can clamp around them

• otherwise: glue and clamp without moulds, clean off squeeze out,
  when confident, remove nails and clamp using moulds

• (Outer pair will be laminated later)

Frames

Dimensions:

• frames should be constructed to extend 50mm each side, and 25-30mm top and bottom

• frames will be trimmed later, final dimensions determined by guitar sides

Cut all pieces, using laminated cover for measurements

• Note that lengths on all curved pieces, and the heights on all straight/vertical pieces, can be rough

• Since the two cover pieces were trimmed on the belt sander,
  the widths of the vertical pieces will need to be adjusted.
  label these pieces to match the corresponding cover edges.
  Do all this before gluing (or there'll be some awkward chisel work)!

Laminate the individual pieces, as in access_port.docx diagram below

Notes

In every single case:

• Vertical, straight pieces are "inside" the curve, in in the concave side

• Top & bottom have "longer curved pieces"

• Sides have "longer straight pieces"

• Don't worry about squeeze out from the frame inner edges, that can easily be sanded.

• However, do clean up squeeze out from the inner, "stepped" corners (where the shorter piece ends), as this area is a glue face in the next steps.

Clamping

• Tops and bottoms: can be clamped "as is", as vertical-grain pieces are "thin". However, the access port moulds (and matching cauls) can be used if desired.

• Sides: used pairs of small curved cauls, ideally *just* short of the curved-grain widths

Assemble each layer using cover as template,

• Separate layers, sand all surfaces so that joins are "flat"

• Hold assembled (with covers in place) and trim roughly

• Do not glue frame layers together

Drill holes in cover and frame

Use regular drill press, Dremel has some vibration issues
1/8" bolts - will use brass nuts and bolts
Using aluminium corner-hole guide, drill first in corners of port cover, from outside inwards

use a sharp drill bit
3mm holes, centres about 6mm in from edges
back with some 13mm scrap on drill platform to get curved surface horizontal

Then drill holes in back layer (of frame) using cover to guide drill (press all layers together)

back with a suitably-thick strip of scrap, to raise workpiece so it hole is level, and also provide clean exit hole

Cut two nut-strips of wood, 4x15

position so they overhang the opening by about 3-4mm
this will support the quite close-to-the-edge hole in the inner layer

Drill 3mm holes in the nut strips, matching those on each side of the port
Enlarge these holes to 5.5mm, but only halfway through (ie, 2mm), on the surface that will be glued to the inside of the frame
Hammer nuts into these holes, so that they are flush with the surface
These are to hold the nuts so they will neither twist, nor be pushed forwards when screwing in access port cover
Do not glue yet - final step requires sides to be completed

Neck block & tongue assembly

In the following discussion

• The term "receiver" refers to the neck block, specifically with respect to its engineered (rather than cut) mortise.

• The term "neck tongue" refers to a piece that will eventually be glued into the heel, thereby becoming a tenon

Plan neck block width

It is therefore advisable to construct an oversize neck block, then trim it to size (and squareness)

Resaw and mill 19 x 90mm tas oak stock into 8mm stock

two boards can be got from one length

Cross-ply laminate to form receiver backing plate (will need two side-ply pieces butted together)

Note that these lengths are the original, non bolt-on neck design. For bolt-on neck, we'll be trimming them shorter.
Trim square when dry

Rip 19mm thickness stock into three pieces per guitar, will form the "receiver" of the neck tongue
NB: each of these measurements are after trimming - can make some of them larger and trim/cleanup

Glue to the cross-grained face of the laminate block,
in the shape of a "U", with the thick piece on the right.
Use the base & thin upright to ensure the channel is perfectly square to the laminated block

• slower-but-better: glue it in three steps, bottom, thin, then thick

Use some 19mm waste as a spacer while gluing
Trim/clean up on table saw, round-over the show face (thick upright side) - but only if not bolt-on neck option
NB: after trimming, width should be 65/67mm, thin upright should be 19mm, as per table above.

Neck join tongues
Resaw & mill some 65mm width stock to 5mm and 9mm thickness boards (perhaps even 4 & 11mm)

two outer layers, grain lengthwise (up & down), 5mm thick
one inner layer, grain sideways (ie inline with as neck), 9mm, will have to butt-join (don't bother with 75/80/110mm wide stock)
laminate, trim, thickness to 19mm using holding channel jig and drum sander if required (minor adjustments can be done using belt sander)

Alternate method for neck tongues to ensure perfectly aligned holes

• Assume bolt-on neck option (top hole lower down for fretboard support extension tray and vertical bolt)

• Use five layers of 4mm stock, the inner three transverse grain, outer two lengthwise

• Innermost layer is split into three pieces, glued with 4mm bolts as spacers for holes

• These voids act as pilot holes to guarantee perfectly aligned holes when drilling

Check tongue fit into neck block

NB: Label each side of tongue top/bottom/neck/body
NB: leave some space at the bottom, for vertical adjustability

Choose nuts (need to be set into tongues)

also bolts (need to be 60mm long, and possibly trimmed later)
I chose M6 60mm Allen-headed bolts & matching 5mm deep nuts (or transverse barrel nuts)
That means the main holes need to be 6mm diameter

If not using "alternate" neck tongue construction

Use centering jig to drill two holes in backing plate

• measure 15mm from each end of tongue

• NB: for bolt-on neck option, top hole needs to be 35mm from top of tongue

• with tongue centred vertically, mark positions in receiver channel (leave space above and below for adjustment)

• a centering jig is a piece of 19mm stock with pilot hole dead centre

• insert into receiver, drill holes through pilot hole into backing plate

fit tongue, use holes in backing plate to drill starter holes in tongue
remove tongue from block, finish holes in tongue,

using transverse-barrel nut squaring jig to keep the holes as straight as possible (ie, exit in the centre of the tongue)

For "alternate" neck tongue construction

• enlarge holes in tongue, use those to drill holes in backing plate

Glued neck option

• Bolts are for clamping neck to body, not intended to remain in work

• Tidy slots are acceptable aesthetically, but could conceivably be plugged or covered

Bolt-on neck option

• Bolts remain in work, allowing easier neck fitup, fretting, French polishing...

If using standard nuts: drill 10mm deep 10mm diam counter-holes in the exit (neck)

• Force-fit two nuts into 10mm holes, so they are flush

• Note: the inner nut is the only one that will apply tension, the outer is just to prevent it from being knocked forward

• Clamp tongue to avoid splitting

• Thread one bolt 25mm onto the nut

• Use the bolt as a centering guide to hammer the nut into the 10mm hole

• Once the nut is just beneath the surface, tap it out, thread the second nut just nestling, not locked, and hammer them both all the way in

• Check that the bolts can engage with the nut from the other (body) side

If using furniture barrel nuts: use jig to drill transverse holes

• Use stainless steel barrel nuts

• They are typically too wide, and will need to be ground down

• Use either a drill bit, or a M6 bolt to hold the tongue in the correct location

• This means we can only drill 10mm starter holes (do one on each side)

To facilitate fitting the neck, there is one more step

• vertically elongate the two holes in the neck block, 2mm top and bottom
  very carefully use router table with fence attached
  This will allow the tongue to slide up and down, and tightened at the correct height

Controlling the router to get tidy slots is tricky, options include

• enlarge the holes using a drill first, so that the router can spin freely on startup

• before locking the fence, spin the router backwards so that it nudges the work until there is no engagement

• use a smaller router bit (but most smaller bits aren't long enough)

Bolt-on neck option

• construct neck block and neck-tongue as per regualar glued neck, with two exceptions:
  (a) the top bolt-hole needs to be 20mm lower (allowing for both tray and additional downwards-poking bolt through tray)
  (b) don't do the round-over on the wide edge

• prepare fingerboard-support extension and support tray components, as per diagram below

• The 16mm thickness allows for some thinning down later while still having enough clearance for a flush-bearing router bit for soundboard

• Cut off top 13mm of neck block, at a one degree angle (~0.7mm across the 32mm of neck block)

For a 110mm GP:

• cut off 12mm (leaving 98mm)

• raise bottom of piece by ~1.7mm to get one degree

• cut bevel

For a 105mm Parlour:

• pretty much the same

For a 140mm Bass:

• raise bottom by 2.5mm

• Prepare and glue fingerboard support extension and support frame pieces, 13 and 16mm deep,
  Depth:

Width:

This can be achieved by making the side pieces thicker, or the tray end-piece longer
Length:
leaving pocket 39x{extension}mm:

• Glue support tray sides to neck block
  NB: at this stage:
  both pieces should be at final width
  the fit should be perfectly flush and square

• (Check that top neck-tongue bolts can still be fitted)

• Confirm that everything is square and flush, for fitting the side bracing

• Clamp work in side bracing channel jig, and cut away two triangular channels along each side
  Cutaway side: 8mm
  Non-cutaway side: 5mm

• Trace, cut and glue matching triangular (or rather, trapezoidal) pieces of 8 & 5mm stock

• Proceed with build steps until it is time to fit neck

Truss rod (if not using a bought one)

NB: Regular acoustic guitar truss rod is too long for my GP model

there is not enough room for neck-tongue slot!!!
Therefore, can only use bought truss rods for bass
(as nothing available in parlor size)

Make Martin-style truss rods as per this video

https://www.youtube.com/watch?v=ysKRHdIaaEg

with some changes

use a furniture bolt "socket" nut instead of T-nut
12*12mm channel
M6 threads
3/16" / M5 washers (small diameter, they fit M6 threaded rod)
truss rod nut make by grinding flange of hex socket barrel nut

Lengths

take body-fret position (eg 345.1 for 24.5" scale, 14th body fret)
-25mm (neck-body clearance, also space for neck tongue channel)
-2mm (socket nut flange)
-0.5mm (washer)
This is the aluminium channel length (318 in the above case)
Cut/grind coupler/barrel bolt to 15mm
Threaded rod should be this length +8mm (will be trimmed later) (326 in the above case)

Method

cut threaded rod & aluminium channel to length
grind a 12x12mm square nut so that it friction fits in the middle of the U-channel, so tensioned threaded rod pushes against it for more bowing
fit regular M6 nut - the torque nut
fit furniture socket nut - the end nut
tighten them against each other
grind the sides of the torque nut square, with three facets flush with the furniture nut shaft
the rod, nut torque nut and end nut shaft should fit snug into the aluminium channel
weld the torque nut to the rod, then re-grind so it's square again
temporarily insert a long bolt into a hex socket barrel nut
grind off the flange, then put temporary bolt into hand drill, and hold it against grinder while spinning, to form a cylinder shape.
Finally use drill press as a "lathe" with sandpaper to polish it.
grind off the tops of the threads above the inserted square nut if required, so nothing extends past top of U-channel

U-channel

cut 3mm slots 17mm from each end (into the "top" of the U)
scribe a line 10mm from the U-bottom (2mm to be removed)
grind/cut/file/sand between the notches, so the U is 10mm high (notches now mark "flaps")
insert threaded rod one end
bend over the flaps at each end (vice)
grind off the portions of end-nut flange that protrude, leaving a squared end

NB: important

• the threaded rod is only approxomately the length we need

• if it is left too long, the truss rod adjustment nut will bottom out

• remember (and check) that our adjustment nut has about 8mm of usable thread

• thread a dummy nut, cut rod to exact size, remove nut so thread is useable

washer, wax/oil
spray with water dispersant
assemble & test
when adequately oiled, seal open side of channel with masking tape, and trim so channel sides are not covered

Neck, headstock & heel

Cutting necks to ~14deg angle

The table below takes into account...

• kerf losses (in combination with 14-degree angle)

• headstock veneer

• headstock section initially thicker to leave enough "meat" for the volute

Stock width: 65mm

Scarf joint table

"Scarf cut start" measured from heel-end, scarf cut will end approx 75mm further towards nut/headstock.

Heel pieces

Cut from same piece as neck, and adjacent to body-end of neck stock

Rough lengths: 125, 95, 65, 55, 50, 45

Cut heel and neck/headstock pieces, labelling each piece so that stacking the heel pieces can be done with exposed end-grain aligning nicely
Use well-rested quarter-sawn 65*19
Label so that any bow is *upward*, we don't want any back-bow baked into the neck

(fretboard will tend to produce more backbow, and we want to let the truss rod take care of it).

Cut scarf joint using jig on table saw

Aim for kerf to be evenly spaced around scribed hypotenuse line
Clean up wedge-ends by stacking so that hypotenuses align and sanding
NB: do this before drum-sanding the neck piece.
Get rid of any uneven saw grooves, blade-burn, and make sure each wedge-edge is straight and square

Mill neck stock down to a tapered thickness

Using neck-taper wedge underneath, make sure the thin end is where we want it thick, and vice-versa
Aim for 10mm at the headstock/nut end, and 18(ish) at the heel end
Do not do this to the headstock piece, we need it to be thicker, so that it can "slide down the fretboard" by about 12mm, to give "meat" for volute
Mill the "shallow wedge angle" side, not the sharp one (which would shorten the piece)

Finesse the two scarf joint faces with sanding block

Clamp both pieces together (neck piece on top) and level so all faces are perfectly co-planar
Sand so the combined plane is perfectly smooth, and all borders of the sloped faces are square

Align scarf joint using scarf joint clamping jig

This will solve two problems

• It stops the two wedge pieces from being pushed apart when clamped

• If keeps the neck and headstock piece co-linear, ie prevents rotation

Glue up & clamp

If headstock piece is not perfectly aligned with neck piece

(This was more a problem before using the clamping jig)
After gluing, mark a true centreline along the headstock, taking account of any rotation if the headstock piece was not perfectly aligned with the neck piece.
Use masking tape to shim sides of the headstock (or trim using table saw), so that they are parallel to this line
This is necessary as the headstock sides run along the router fence when cutting reinforcing spline channel.
Any headstock non-alignment may also affect cutting the truss rod channel.

Use the heel alignment hole jig to drill 9.5mm holes in the heel pieces, then use a bolt when gluing them up

• It will help the pieces stay aligned, and not slide when clamped

• It will also assist with clamping (although additional clamps are still required)

Glue up heel pieces, making sure the grain lines up, but don't attach heel to neck yet
Clean up the upper face and sides of the headstock, perfectly flat, straight & square

Reinforcing spline

Cut a channel along headstock, 8mm deep, about 18mm wide,

"bevelling off" into the neck (see diagram below)
use router table
channel should be aligned with neck (if any rotation in scarf joint)
always feed the piece right-to-left to avoid router pulling it away from fence

Mill and glue in spline, then level with sander, sandpaper etc.

Cut truss rod channel (12mm wide, 10mm deep) using router table

NB: do this before attaching headstock wings!

Headstock wings

NB: cut truss rod channel first!

Before attaching headstock wings

• Rip headstock piece to 52mm wide (balanced around centre)

• This will place the two heastock wing join lines "inside" the headstock, avoiding them appearing along the headstock sides

• It does however mean we have to do a bit of extra re-jointering...

Rip some 19mm stock, cut to headstock length-20mm:

Don't make them any wider than they need to be, thinner = more flex = more forgiving of imperfectly-jointered surfaces.
(Trim width to about 20mm or less)
Rough-up the outer (dressed) sides (or clean up the ripped faces), and glue to headstock,

starting around 20mm from top neck-headstock vertex.

Trim headstock ends square - NB: square to NECK, if scarf joint rotated a bit!

Thinning headstock, also forming volute curve

Remove dust shroud from drum sander
Slide headstock under sander drum, find end-position to leave volute "end" curve

• make a mark on the neck, 18mm from the inside scarf joint line (don't press too hard, pencil lines can dig into the neck)

• using a square, position this mark under the "start" of the drum

On the sander outlet end, clamp a stop piece at the position of the (squared) headstock end
Jack up drum sander dust shroud with ~32mm offcuts (clamp them for security)
Thickness headstock to <11-12mm (depending on the headstock veneer), pushing the headstock under the drum, against the stop piece, then out again

• there will be a tendency for the drum to stop before the workpiece hits the end-stop

• this is because the drum will nestle into the circular profile it is creating

• from time to time, check that the piece is really hitting the end-stop

• aim for about 28mm of unsanded headstock underside

Turn the neck around, move the stop piece, and give the lightest dressing to the underside,

• just "kissing" the scarf joint

This should result in a volute apex with the following characteristics

• 7mm in height, 2-5mm in length of unsanded headstock underside

• after accounting for bevelled headstock veneer and nut thickness, apex should sit at the zero-fret position

Headstock veneer

Resaw & mill Blackwood and Celery-top Pine to <2.5mm, laminate

Show layer is Blackwood, the pine is to provide a contrast stripe around the outside
Aligning the pine layer cross-ply may strengthen the headstock wing joints, however it also causes three issues:

• it may render the piece curved, causing problems when thinning in the drum sander

• when sanding the wedge, the bulk of the work must be done after gluing it to the headstock, as the lower layer has edge-aligned grain

• when trimming the sides of thinning the neck, pull out is an issue as part of the top of the neck has sideways grain

• therefore, if doing it, it is essential to have longitudinal grain at the neck-end

• one solution would be to have a piecewise transverse section in the middle (where it won't be seen), with longitudinal grain all around the outside

Recommendation: don't do it
If the result has some curvature, moisten, heat and clamp to remove it - this can cause uneven thinning in the drum sander

Previous method: using a handmade 3:1 reduction pantograph and Dremel router

clamp pantograph to upper right corner of router table
use wrapped stylus, so no play in template channels
clamp work-holder jig "underneath" that, perfectly square
clamp template 200mm from bottom left, with piece of 19mm stock for stylus "rest spot"

template should be pretty square to table

see image below
put mill bit in Dremel as far in as it goes
make sure the chuck is tight!!!
make sure workpiece has headstock outline, logo position and most importantly, centre line marked

draw cross-line 40mm under the top wave-motif line - that will be base of "M"

soft-clamp the workpiece in the work-holder jig

hover stylus above M-middle-bottom, move workpiece so mill bit is on crossline-centerline intersection
make sure *centerline* of workpiece is square to holder jig (and therefore, table top), screw down wingnut clamps

rout the inlay, "hovering" the stylus at first, then all the way in
make sure to go back-and-forth on all three M-feet.

Resin for simple logos (without very fine lines)

Mix some clear glass sparkle, turquoise glass sparkle and fine green glitter in a mini bowl
Fill the routed channels with glitter mix, to just under the top

- should be able to scrape an edger over without dislodging any

Apply a few drops of low-viscosity CA glue to partially fix the glitter in place
Mix a capful each of epoxy resin and hardener in a plastic cup (or cut off plastic bottle, whatever)
Drizzle the resin in careful not to drag the glitter around (CA glue should reduce this risk)

- make sure it covers each edge

Butane flame or heat gun to de-bubble

heat gun underneath to encourage resin to ooze down into channel
more butane flame to get rid of additional bubbles

Current method: using a CNC router to engrave a logo with fine lines

• My own custom "Magnusson" logo

• 30 degree V-bit

• Stabilise grain by soaking some waxed shellac, diluted with alcohol, then wipe off and allow to harden

• Lightly draw the centreline along the veneer stock (this line needs to bisect the middle "n" of the logo)

• Trace the outline of the headstock from the wooden template

• Transfer a line running through the two top tuner holes onto the veneer

• Check that this line is perpendicular to the centre line

• From the intersection of these two lines, find the point 20.3mm up the centre line

• This point is the origin of the logo G-code, carefully position the bit to it and choose "Center XY".

• After carving, lightly drizzle some CA glue into the channels to seal them. Do not allow it to pool anywhere

• Mix some clear epoxy resin (one capful of each component), with two "scoops" of Opal White mica powder
  (a "scoop" is from a 10mm piece of bindings strip)

• Drizzle the resin into the channels, de-bubble with a heat gun or blow torch

• Allow resin to set until very hard - two days depending on weather

• Sand down to wood - be very careful if using drum sander

Mark up the headstock logo and cut veneer-neck transition line

Before any drum sanding, transfer the two end-points of the centreline to the sides of the piece

(so that we can recover it after it has been sanded out)

Carefully drum sand the veneer, first to reveal clean filled channels

then (front & back) to get down to 4mm.

If drum sanding pulled out any pieces of glitter/resin

fill with CA glue (may require more than one application) then level with fine sandpaper
NB: do this now, and keep doing it until the surface is perfectly smooth. French Polishing is not the time to discover this was not done adequately!

Reestablish the centreline, using the two "saved" end-points, above)

• For the "M" logo, the line should go down the middle of the centre pillar of the "M"

• For the CNC logo, it should go down the middle of the middle "n"

Retrace the headstock shape (onto the veneer) from the template, aligning with the centreline

Important: find the centreline at the far end of the headstock

Beware: if scarf joint is not perfectly square, more care is needed to find correct centreline
Transfer line so it is the same front and back

NB: in the following steps, 16mm is assumed to be the run of a 14-degree wedge of 4mm thick veneer

if the veneer is thicker or thinner, adjust to match

Trace two more lines onto the headstock veneer:

transverse line for the back of the nut,
and a parallel line 16mm forward (towards neck/body) of that
cut along this line

Mark a line on the headstock 16mm back from the scarf joint - this will be the back of the nut.

Cut truss rod nut channel and begin transition bevel

Plan for truss rod adjustment nut to extend 14mm further past the headstock end of the nut

The aim is for the end of the truss rod to be underneath the thickest part of the volute
Drill a 6mm hole in the veneer 20mm past the headstock end of the nut (4mm past planned end of truss rod nut)
Cut a slot up to the hole on the bandsaw
This slot will be wider, but we will finish it with a rat-tail file
The hole is just a guide

With the bandsaw, trim away some of the veneer waste around the nut-to-wings flare
With the belt sander, cut off about 80% of the "upward sloping" edge of the veneer,

making a bevel, coplanar with the top of the neck.

Glue infill into portion of truss rod channel along headstock

Mark zero-fret line on neck
Mill a 5mm strip of softwood infill for the "sloping" portion of truss rod channel
It will be about 40mm long
Taper it down to about 1mm height towards the zero-fret line
Glue it in, and bevel the portion that stick "out", level with the headstock face
This will improve the appearance of the truss rod nut slot

Glue veneer to headstock

Glue veneer to headstock aligning previously drawn centrelines

use two small nails (outside headstock perimeter) to prevent slippage while clamping
use cauls to even out pressure since the veneer is thin

Finish veneer bevel with sandpaper and/or scraper, making a perfectly flat and flush transition to neck
Finish truss rod adjustment nut slot with rat-tail file, to allow hex key access

The slot will parallel with the neck, bevel "up and out" of the headstock

Now is a good time to check for any neck-bow - remove by sanding and/or clamping

Continuing the neck

If pursuing bolt-on neck experiment

• Mark body-fret line on neck

• Mark neck-end of truss rod (notes immediately below)

• Using router, widen & deepen truss rod channel at heel end to accept fingerboard support extension "prongs"

• 16mm deep, as wide (and asymmetrically placed) as the support piece itself

• Neck will be 18mm thick at the heel end, leaving 3mm at bottom of neck piece

• Don't bother squaring them off, fitting the fingerboard support extension needs to be done later

Position truss rod so the end of the adjustment hex-nut extends 14mm past the back of the nut

Note that this corresponds to the aluminium section lines up with the fingerboard, and ends at the start of the nut.
We want the truss rod adjustment hex barrel to "just" protude up through the headstock veneer,
while the end of the truss needs to be above the extra thickness provided by the volute

The truss rod will have two deeper sections at each end (where the flaps are folded)

Use a chisel to carefully deepen the corresponding sections of the channel

If not done yet, put some masking tape over the open channel of the truss rod, trim sides flush
Mix some Araldite, spread some on the sides only of the truss rod channels

glue truss rod in place, if slightly low in the channel that's ok (not high)

If the truss rod is low in the channel

Rip 12mm lengths of very thin timber, glue over truss rod
This is most important in the middle, where it will push up against the fingerboard when tensioned

Scrape/sand everything flush
Using the headstock template, clearly mark & square the position of the *back* of the nut

If all has gone well, this should be *just* inside the newly-sanded/exposed neck-headstock break

Mark a (squared) line 6mm down-neck from this - this is the zero-fret line.

Now we can mark the body fret line

Now we can plan neck width profile

Mark centreline at body-fret, then *centred* body-fret neck width

Mark *centred* nut neck width

Rule in neck edge cut-lines

trace in headstock-neck transition lines (make them symmetric)

Take already-glued-together heel block stacks

If drawing a line on the underside of the neck, don't press too hard, pencil can dig in
Bottom of stack will be ~45mm
Bottom of heel will be 35mm
Position heel stack with about 5mm spare each end
Enlarge drilled hole through heel stack to ++10mm
Drill 10mm hole in neck to match existing holes in heel stack
Glue up, using bolt and clamps

Transfer neck edge cut lines (width lines) to the underside of neck

NB: heel block may not be square - use set-square

Transfer headstock outline to back of headstock:

Cannot cut headstock shape right way up due to headstock angle
This will be hard to get 100% accurate, when we cut it out (later) we'll leave plenty of space so that it can be finished on the belt sander with frequent checking of the front.

Use this diagram to rough-in heel curve.

This is a very rough guide

• Measure 45mm down from the underside of the neck piece

• Measure 33mm in from the bodyline heel cut

• Measure 30mm in from the bottom of the heel

• Trace a quarter circle from that point to the underside of the neck piece

• Extend the bottom part of the curve to 30mm in from the bottom of the heel

Rough the shape in on the bandsaw, then get closer on the belt sander
Cut the body-join line on the bandsaw using the mitre

Be careful that the heel block might not be quite square

Clamp neck to mitre, making sure that everything is square

Now we can cut the neck to width on the bandsaw, leaving about 1mm to sand down accurately

• Start the process - shallow vertical lines along the heel - on the table saw

• Then do the neck side lines, starting with those groove-cuts

Carving the neck shape - facet method, assume 16-17mm neck thickness,
Aiming for a nice "C" shape

• NB: when I am for a "C", I usually end up with a "D", as we will be narrowing the neck edges slightly

• Don't be afraid of removing quite a lot of material!

• First facets 15mm into the back, 10mm up the sides of the neck (9 at the nut?), flaring to 15mm at the heel

• This will leave 6mm of vertical timber each side of the top of the neck

• Second facets 4+4 (moving out from fretboard) and 6+6 (along the inside towards middle) - two of each

• This will leave 2mm of vertical timber each side

• Note that this seems "too much". but our neck is wider than it will eventually be...!

"flare" facets outward around volute and inward at the headstock - don't overthink it, it's pretty easy.
Smooth remaining facets, sand out rasp lines

Use Shinto saw rasp for straight sections, curved rasp for heel curve

Remove some of the scratches with a regular wood file
Avoid using scraper to remove rasp marks on end-grain - it bruises the grain, affecting how it absorbs shellac, resulting in uneven colouring

After cutting the three sets of facets, round everything over with a wood file

Coarse sandpaper to move closer to finished surface

Around this time, if not done already, re-transfer & cut headstock shape (leaving 2mm extra) using bandsaw & belt sander.

Starting fingerboard

Mill Merbau / Jarrah / Spotted Gum to 6.5mm, 66mm wide

Rough cut lengths

Rough in radius using drum-sander sloping jig

Draw scribble lines all over the surfsace
Make two sets of passes through the drum sander, rotating the work lengthwise
We want the two bevels, each being about a third of the width wide
The pencil scribbles allow the depth of cut to be judged accurately

Finish radius with 11" radius sanding block

Sides

Sides philosophy

Since kiln-dried timber is more readily available (and therefore, more choices with respect to grain, quarter-sawn, etc), we have chosen to go with it.
Kiln-dried timber is however much harder to steam-bend, and therefore needs to be milled to ~2mm
That's extremely thin at the best of time, but our steam bending process (with Tasmanian Blackwood, at least) of that thickness leades to lateral waviness
We therefore use a laminating process, to get adequate robustness, and allow sanding out the waves.
Originally I used plain old radiata pine for the inner layer, but I've switched to Macrocarpa

Waviness

Steam bending Tasmanian Blackwood, especially a 2mm thin layer for lamination, introduces waviness across the grain.
Usually 2mm is enough for this to be sanded out before cutting the binding channels.
However, if the bindings turn out to be too shallow, or other unexpected situations, we can end up sanding through the outer layer.

Milling sides stock

Mill to: 2mm (two sheets per side, to laminate to 4mm)

Those measurements assume near-perfect placement in the bender, allow a little more if unsure

Side bending

Assume

mould is in Fox bender with lower bout to the left
if there is a colour gradient across the side stock, we prefer darker toward guitar back

Then

Non-cutaway side: Darker side is to the rear
Cutaway side: Darker side is to the front

NB: New aluminium foil each time! Four layers on wide pieces (bass)

Aluiminium foil stops steam from escaping, and protects against iron contamination (from shim-stock in bender, and filings from when we made the truss rod). Iron reacts with hot, steamy timber and stains it irretrievably black.
Laminate each pair backwards, so blackwood "show" side is protected by what will be the inner layer

Shim stock process

Steel shim stock protects the timber by evening out bending stresses and heat
Under the wood: one layer of aluminium flashing, sprayed with black engine enamel, to better absorb heat lamp energy.
Aluminium is also bendier, less springy, placing less stress on the bent sides when removing from mould
Following that: one layer of 1/100th" steel shim stock
Over the wood: two layers of steel shim stock, but the outer one only over the waist and cutaway area

Heat top shims with heat gun while operating the Fox bender.
Order of operation:

Tighten waist press screw to keep mould and work steady
Make sure work is parallel with sides of mould
Measure so that the work piece will extend about 40mm past the end of the bottom of the mould's lower bout
For all the following steps, play the heat gun over the exposed top shim stock, to help heat the workpiece
Bend down the lower bout, keep it in place with the spring clamp
Bend down the upper bout, keep it in place with spring clamp and/or cutaway press screw
Slowly tighten waist press screw
If making cutaway sides, even more slowly tighten cutaway press screw
Leave work in the bender with lamps on for about 5 minutes, then let them cool down for about 45 minutes.
After removing them, allow each piece to dry thoroughly before next steps
Consider clamping them in the laminating mould to dry, to reduce springback

Also

Do the bindings while the Fox bender is set up

Three layers, accent colour on the inside

See bindings thickness plan at top of this documnent (Milling bulk stock in advance)

Make sure grain is straight along the bend dimension
Bend bindings in two batches per side

• Thicker layer can be pressed hard, as we need it as tight as possible

• Thinner layers need gentler pressing, so they don't compress into thinner sections at curves

Side Lamination

Place side pairs in laminating moulds, and trim off excess that otherwide prevent moulds from standing on workbench
Laminate pairs in laminating moulds
Radical decision: use Polyurethane glue!

fills gaps due to inadequate clamping
(Aliphatic glues, ie Titebond, produce voids, even with the best clamping)

Procedure

Put masking along sides of both mould and clamping caul, extending sideways
Apply glue sparingly!!!
It is critically important that the sides are perfectly aligned with the mould, clamping tight from one end to the other can cause this to "creep in".
Loosely fit all clamps, check alignment, then tighen
Note that the masking tape may make this problem harder to see
Too much squeeze-out makes extraction from mould tricky (hence masking tape)
If any squeeze-out has gotten onto mould, remove from mould *approximately* after three hours (depending on weather/temperature),

while glue is soft enough to separate easily,
but inside the lamination, strong enough to hold

NB: if taking the sides out of the mould early, put the cutaway side back in afterwards, and reclamp
- tight - so that there won't be any spring-back due to soft glue (which then hardens, cementing the wrong shape!)

Fitting sides to solera mould

• finalise neck-width at body-fret, create shim between solera mould-halves so cutaway-edge-to-centre is half that
  Do not skip this step - solera moulds are a little thin on the neck join

• even better, glue permanent shims for the standard neck width, so that we only have to shim for 12-string (or 5-string, in the case of bass)

Fitting sides into solera mould is tricky, follow these steps carefully

• Manually estimate cutaway end, as it will not fit into mould until near-perfect

• Cut outside that estimate, fit inside and see how much needs to be trimmed so cutaway curve matches solera as closely as possible

• Again, cut slightly less than that, repeat until satisfactory

• Fit both pieces inside their respective half of the solera mould

• Mark how far the tail each end extends

• Cut 5mm short of that line

• Attempt to clamp the two halves of the solera mould together

• The tail will be out by about 10mm, mark how much needs to come off each side

• Cut slightly less than that off and reclamp

• The neck end will be way out, measure the gap between the two neck-ends of the solera mould

• Cut that much minus 5mm from the non-cutaway side

• Reclamp, check if solera mould can clamp together tightly

• Also check verticality of sides around perimeter

• Keep cutting a little at a time until perfect

• A misaligned centreline at the tail end is quite OK, it will be hidden by tail strip and access port cover

• Depending on how secure the fit is, out-pressing turnbuckle clamps may be needed while cutting front and back profiles, and gluing access-port frame and neck block

Trim top of sides to create soundboard edge

if sides are loose, consider gluing a temporary joiner piece to the place where the access port will be cut out
Spokeshave time

• use laminated MDF reference flat surface

• raise frame slightly and evenly

• make sure every point along the sides are vertical (use set square)

• slide a pencil around the inside perimeter, drawing a line

• shave and plane to that line to get a perfectly flat top edge

• edge can be checked with MDF reference surface

• sticking sandpaper to MDF surface with double-sided sticky tape can zero in final flattening

• NB: we only need it flat so we can measure the curved back profile points

• the actual top profile will be adjusted to a more complex curve using a very shallow spherical sanding dish - later

Trim bottom of sides to create curved back profile

Take care around cutaway - height *increases* towards centre!

• two-dimensional curve

• longitudinal curve governed by curved sanding stick

• lateral curve much less than sanding stick curve,

• lateral curve near cutaway with shorter, shallower sanding stick

• This can be roughed in, and finessed later (after kerfed linings attached) with curved sanding sticks

• If a well-shaped result is achieved while still too high, keep it - it is much easier to cut down the flat topside to the correct size

• Turn work over to check "roll" of edges against flat surface

• Avoid any "sharp" spots (tilt rather than roll), they will make fitting bindings more difficult

• There will be a very slight tilt spot at the cutaway, as the sides curve towards the centre

• In paricular, the measurements above have a sharp spot in the middle that is intended to be rounded over

NB: this is from the most recent build, which turned out a little flat in the middle.
My next build will use a hybrid of that profile and the previous build

Gluing neck block

Mark guitar centreline on various faces of the neck block & neck support tray
Place sides onto soundboard clamping mould so that we can position the neck block and check squareness and lateral position
NB: neck width at body fret needs to be considered

need centre of tongue-channel to be 0.5*neck width from outside of cutaway face

(see table above)

if the solera mould had been correctly used, this will be the mould's join lines
leave the support tray 0.5mm proud, but the heel cap end can be flush

Mark the three curves or angles that need to be cut on the neck block

• One on bottom, to fit into curved back - flat OK at first

• One at the side, to fit into cutaway - will need to be sanded concave

• One at the mortise end, to fit the tiny amount of non-cutaway-side curvature

Cut just shy of the lines using the table saw
Finish them by hand by various means

• Use the narrow convex sanding block to match the shape of the inner cutaway

• Note that some of that sanding will on end-grain, and sandpaper will cut it less than side-gain
  use a sharp, narrow chisel to even out the load

NB: Double check that sides (especially around shoulder/cutaway) are square to the front. Gluing the neck block commits to the that alignment.
NB: Double check that neck block, when clamped in, is square with the body centre line
Glue and clamp

Gluing access port

Assemble all layers together (two sets not glued), cover screwed in place (for alignment)

• NB: cover can't be in place if "temporary joiner piece" glued at seam

Position, centre vertically and horizontally, mark layers, trim leaving ~1mm top and bottom
Glue outer piece, so that the extra 1mm is evenly distributed top and bottom

• clamp the outer ends with same convex clamping cauls used when laminating access port frame upright components

Don't bother sanding it flush yet, wait for the kerfed linings.

Mark true centre, top and bottom, tail and neck
Remove from mould!

(possible thanks to over-engineered sides and single access port frame layer)

Cut ~2mm deep slot (dado style on table saw), then cut and fit tail strip

(much harder to do later, after we cut the actual hole)
Also, end-tear-out is less of a problem now

(Surface tear out can be managed by decent blade and/or slow feed speed)

Centre over true centreline (might not be sides join-line)
Before finalising width, put back in solera to check alignment
Glue in, then trim and level
It is quite acceptable to cut the tail strip in two so that it just covers top and bottom, as the access port hole is about to be cut out

Using drill, hole-saw and router(flush bearing bit), remove material from hole

Drill and hole-saw: remove the bulk so the router does less work
Router: flush bearing bit to rout sides to line of access port outer layer

Remove any glue on access port sides first, so routed line is straight

Square out corners with rectangular file so cover fits through

a regular rectangular fire, while slower than some alternatives, is safer:
Make a notch in the rounded corner, then work it outward and downward until both edges are straight.

The end result of this step is that the cover should fit through (and sink into) the hole, so that it is flush with the inside (ie, to its final depth)

The steps involved include

• Making sure the outside hole perimeter is straight, square and it true corners

• Fitting the cover in as best as possible, then putting your head inside the guitar, looking in a light source, and noting tight spots

• Drawing lines with a pencil to show when you are filing parallel to hole edges

• At the very end of the process, it might be appropriate to sand the cover itself, particularly to adjust the angles of the two upright edges

Fit inner layer (using partially completed cover to align)

• since we need to use the cover to align it properly, we cannot do this inside the solera mould

• this introduces the risk that the final curvature might not quite match the mould, or the cover itself

Problem of inner layer springback

Clamping outside solera mould may change tail curve
Access port cover curve may no longer match access port frame

Current procedure

After gluing in the middle layer, inspect:

• The resulting curve of the sides+middle layer

• The curve of the as-yet-not-glued-in inner layer

• The curve of the cover

Take remedial actions as required:

• Relax or tighten curvature of middle layer before gluing by wetting, heading, clamping

• Relax or tighten curvature of cover (wet / heat gun, clamping)

• Consider whether the laminating moulds need to be remade/adjusted before laminating in the first place

Also, consider

• just how different is the curve?

• Will it still fit into the solera?

• Remember cover will be bolted in place, inside solera when attaching back and soundboard

• Will the difference in tail curve be noticeable when the guitar is complete?

Previous approach (not recommended, not shown in images)

• rub some candle-wax around inside of cover

• rub some candle-wax around non-glued surfaces of frame

• put sides back in solera mould

• leave cover in place while clamping

Mark sanded/trimmed top & bottom line, trim
Holes drilled yet?
Glue and clamp inner layer,

• fit cover (including bolts) to ensure the two layers align

• note that some of the inner layer face does NOT require glue!!!

• use frame-to-sides clamping caul with exact shallow curve at each side of the frame

• remove cover immediately so it won't get stuck by glue squeeze out

• clean off all squeeze out from cover and inside edge of frame

Finish access port

Prepare the following

• outermost layer (actual show piece), ~1.7mm, curved

• second-outermost layer, <2mm, also curved

• some strips of border accent wood, ~12 x 2mm, straight

To create the outermost lamination

• Carefully trim/sand second-outermost so that it fits into the hole,
  OK if it doesn't quite go all the way in against the cover

• Cut border strips with the top and bottom pieces full width and the uprights fitting between them

• Cut the outer centre panel so that it fits between the border strips

• Use sacrificial backing, as tear out affects the show face

• Glue and clamp top and bottom strips and centre panel

• The cover can act as a clamping mould for this step, since the top and bottom border strips are not pre-curved

• When dry, excavate any squeeze out from the channel where the side border strips are to go

• Glue and clamp the side border strips

• sand the border strips flush(ish)

• redo the fitting, as perimeter will have changed...

This almost final perimeter fit

• trim to within ~0.5mm on table saw, cutting "inwards" to prevent tearout

• sand top and bottom so that the piece fits

• for each side, slide up, inspect gap - there will be some unevenness

• sand out until each end slides up perfectly

• check overall width, reduce and reprofile appropriate side-end as needed

Before proceeding, check that inner cover curve matches guitar

• if it is too shallow, consider shimming the two side edges

• if it is too deep, consider shaving down the two side edges

• also consider wetting / heat gun / clamping to adjust curve

At this stage, it may turn out that the cover doesn't sink in as far as it should

• This may lead to the outer layer being too proud, and requiring too much levelling

• Especially if the two outer layers are too thick

• Consider very gently sanding the outside of the cover, to thin it a little

• Don't overdo it, glue squeeze out on the cover show face (panel, border) will require some levelling

Tack two thin nails through inner cover, poking outwards 2mm

Angle (relative to the curve) so they're parallel with each other (not flaring out)!

Fit inner cover
Press outer cover layer into place, impaling it against the two nails
Remove
Laminate outer layer, using nails as index for alignment

• remove as much squeeze out as possible, as sanding/scraping/chiselling it from a fit-critical edge is not much fun

Remove nails

Extend five holes (strap button in middle, four countersunk screw holes at corners)
Fit cover in place
Screw four corner bolts through holes (apply some candle-wax first)
Glue in place the two nut-strips we made when laminating access port layers

Best done with cover in place, but need to manage squeeze out
Rub some candle-wax around inner edges of cover
Apply glue to inner face of nut-strips (if possible, not the parts exposed at the edge)
Position nut-strips in place
Tighten four bolts so they engage nuts and extend inwards
Clamp (bolts are only pulling against nuts, nut-strips are just sitting over them)

Extra steps for Fat Parlour

(Optional on GP, not required for Bass)
Cut and glue in some extra strips around and over the nut strips top and bottom

• This is because to make the access port high enough, there is not very much wood top and bottom

• Most guitars have a solid tail block here, we've got this frame with a large hole in it

Hopefully end up with cover fitting, as well as the four bolts
Scrape and sand flush if any major level discrepancy (lots of further sanding to be done later)

Clearly mark centre lines on side frame

both ends, top and bottom, glue faces, inside, outside
I mean, it's so annoying when you have to keep working it out again...

Kerfed lining

19mm stock, rip and mill to 7mm, the put a radius on one of the side edges
Bandsaw guide - slotted stop board,
use headless nail to get each cut "evenly" spaced lol
Also use bandsaw table extender
Cut and glue in place, top & back, clamping with washing clamps (see image)
NB: for inside the cutaway horn section, the kerfs will need to be widened with a file, beveling the blocks so they can pack closer together
Using the Shinto (not band-sander!) trim to a whisker above already-prepared top and bottom profiles, then sand by hand to get perfect surface for gluing

Bolt-on neck experiment (though this also applies in general for getting correct neck angle)

• When levelling the soundboard edges of the sides, we want the extended "tray" of the neck block assemble
  to slope upward slightly, corresponding to the tiny amount of curvature the soundboard will eventually have.

• Previous attempt: when extending the tray line along the length of the guitar, have it end 5mm above the tailblock edge.
  This makes the cutaway a bit problematic - the sides have to be higher to "meet" the higher neck tray.

• Current attempt: use a 9m (29.5ft) radius sanding dish, but in a sort of hybrid way:
  we only really want the spherical side profile at the neck-cutaway area, we want it pretty flat everywhere else.

Resawing, milling, butt-joining back and soundboard

Raw minimum dimensions (cut longer and wider for jointing and positioning leeway)

both pieces, both sides
Mill timber to 5mm
Resawing on the bandsaw - use resaw post, lock the fence down proper!
NB: pay special attention to drum sander scarring: particularly if using 60-grit sandpaper.

If perfectly parallel to the grain it can be overlooked, but with any lateral movement in the drum sander it becomes an eyesore that is very difficult to sand out, particularly on the soundboard.
A combination of 80 grit, plus some final low-friction passes on the show face, should be enough to keep it under control.

NB: if not butt-joining immediately, store boards clamped between two flat boards to prevent bowing/cupping

Before gluing we need to joint the edges.

• If they are not reasonably square and straight, make them so with the table saw.

• Then finish the job with the aluminium angle jointer sanding jig.

Butt-join using a sheet of MDF, nailed down strips of pine as edge stops

• Cover MDF with oven paper where join line will be

• Raise the two pieces along the join line with a piece of 19x42mm stock

• Show face up

• Position and nail down edge stops

• Apply glue, align, then remove the length of stock and press down

• Check joint alignment, clean off squeeze out (while pressing down to prevent them from springing backup)

• Cover with more oven paper, a hardwood board and weight

NB: after butt-joining, store boards clamped between two flat boards to prevent bowing

When dry, using mould, trace body shape outline (both sides, but lightly on the show faces!), cut with bandsaw, 5-20mm outside line

• For guitars, this can be done after final thicknessing

• For basses, consider doing this after the rough cutout

• Leave flat sections at each end, so they can be pushed through drum sander with a piece of 3mm MDF

Mill to required thickness using drum sander

• First mill non-show faces so that join line is clean and smooth

• Then mill show faces so that join line is clean and smooth

• Finally mill non-show faces (again) to width

• Soundboard:
  Celery-top: 2.8mm
  Huon Pine: 3.0mm
  King Billy: 3.4mm (less?)
  Macrocarpa: 3.0mm

• Back: 3.5mm

Clearly mark centre lines

Bracing and fitting back and soundboard

Prepare (rip, resaw and mill) back-brace sizes and positions

Four,
two x 8*16mm (vertical taper, neck end)
two x 12*19mm (rounded over, tail end)

Spacing (from neck)

While thus tooled up, might as well mill stock for side braces as well

8x5mm, long enough for eight x body height

Prepare A-frame soundboard braces size and positions

Two pieces, 8*19 (vertical taper)

from neck joint to a spread at tail of

2 * 8*17..19 wing braces (rounded over) (outside of bridge to side)

Sanding profiles into braces

Rough-in the profile with (bandsaw?) and belt sander
Clamp sandpaper to moulds, sand until full profile is cut (no flat spots)
Use a holding jig to avoid stressing fingers

• but only during initial hodding phase

• finish with fingers so they stay seated, to avoid rounding over the bottom crosswise

If doing the wing braces, sand across the centre of the soundboard mould, and symmetrical is OK

Planning back brace positions and gluing

Method: caul blocks and go-bar clamp at ends first, clean up squeeze-out, then do middle

Preparing and fitting centre-strips

Cut five lengths of milled 3-4mm cross-grain hardwood
30-40mm wide
NB: the outer two cannot be glued yet (length depends on neck block and access port)

• The reason we glue the inner three pieces now instead of later is simply to make the back stronger during the next few steps

Round over edges, glue the inner three down centreline of back
Use go-bar clamps, same rods as for back braces (with 19mm cauls)

Tapering back braces

Spokeshave, plane, chisel, short block of scrap to check straight lines
Tail end pair: 50mm linear taper down to 1mm at perimeter
Neck end pair: 65mm linear taper down to 1mm at perimeter

Planning and gluing soundboard brace positions

Trickier
Put side frame in mould, with turnbuckle bracing if required
Trace out neck-block, cutaway-kerfed lining, access port positions - to the inside of the soundboard
Mark how A-frame braces need to trimmed to fit (and do so)
Glue: normal clamps at ends, go-bar clamps in middle as per when gluing back braces

For the bolt-on neck option

• the non-cutaway side A-frame brace will be a bit of a pain to cut

• we end up with a bizarre shard with complex angles (see image below)

• don't worry, when we taper the braces, almost all of this will be shaved away

Tapering soundboard A-frame braces

Taper full-scale line (measurements next paragraph) to neck,

then from 19mm tail-ward of that line to tail
(ie around the wing braces)
aim for 2mm at ends

Scalloping: about 5mm dip midway, both ends

Preparing soundboard bridge plate

Body-fret to full-scale line

Mark bridge-line (full scale length)
Bass bridge is 52mm deep, guitars less than 50

- let's just say 50 for all

Cut 3mm bridge plate (slightly thinnger OK if hardwood), 75mm deep (will trim later)

Crosswise grain
Sand in a bit of a lateral crown to match dip in mould

(to reduce the bracing contours appearing when the soundboard is varnished)

Starting 12-15mm in front of bridge line, total depth = bridge_depth+10

60++ is probably about right
That 12-15mm extends a bit, but is good if fitting piezo pickups

wedged between A-frame braces

Trim depth after getting the wedge angle right

Soundboard hole and neck-end support

Both: grain aligned crosswise for additional strength
Soundboard hole support: 2mm hardwood (can be multiple pieces)
hole support: bout to waist, board can be slipped under sides for tracing
For this operation, soundboard should "fit" against mould-encased side frame,
(which should already be traced on the inside of the soundboard)
Neck-end support: 4mm hardwood (back trimmings OK, can be multiple pieces)
NB: skip neck-end support for bolt-on neck option
Laminated below fingerboard on body, nestled in the top of the "A"

Taper soundboard wing braces

cut bevel (optional compound / two-dimensional) so they sit against A-braces
They sit against the tail-ward side of the full scale line, straight out
Sand tiniest possible curve on bottom, then taper from top
Down to >1mm
Straight at first, then optionally with subtle scalloping

Glue in bridge plate, hole support, neck-end support and wing braces

Wing braces aligned with the 19mm full-height section of A-frame braces
Go-bar clamps/deck

Fitting back and soundboard to sides

Preparing to fit back and soundboard to sides

NB: fit sides into solera mould, it makes subtle differences to where we need to cut channels for the braces
Place access port cover in the hole (to support clamping)

will need to drill tail strap-button hole if not done already so that cover can be pulled out afterwards
put temporary 1/8" bolt & nut, protruding outwards as "puller"

Sides are in mould, turn-buckle clamps if required so no gaps
While "rolling" the back over the sides, mark where the braces meet the sides

Before cutting, fill in the kerfs around the marked positions with pine shavings and polyurethane glue
Try to have the filling just go down 5mm, so that the kerfs will look natural through the sound hole,
The idea is that the kerfs stop just before the bit that is to be cut away
This will prevent linings from crumbling when cutting channels

For the soundboard: same deal

Mark channels for wing braces
Fill the kerfs around them with shavings and glue

Now it is time to start cutting the channels

Start at one end, making sure both ends are centred
One brace at a time
Double-check position and alignment at every step
Cut brace channels too narrow, then check, then widen
Sand out incorrect pencil marks to avoid confusion

Cut small channels using small pull-saw, chisel and file

With the pull-saw, make two edge cuts,

make them too narrow at first - better to file outwards than have gaps
then two shallow wedge cuts to meet them,
then cross-hatch cut "hill" in between
finally use file and/or chisel to create the "downward" ramps into the body
check position at each step

Adjust so that back can curve over sides, into place
NB: finish centre-strips at this stage:

Trace neck block and access port edges onto inside of back
cut the final two centre strips to fit, glue them in and confirm that everything still fits

Cut and fit vertical side braces

Takes sides out of frame for easier clamping
rip some hardwood 8x5mm
Same positions as back braces (slots in kerfed lining)
Cut to fit between kerfed linings
15mm taper to 2mm top and bottom

(dimensions not critical)

Cut and fit support backing for pickup socket

• use some spare curved hardwood stock (leftovers from access port?)

Approximate length (see "Drilling for the socket", below)

Cut and fit support backing for neck strap button

• Cut a piece of hardwood about 55x55x10mm

• Cut or sand to match curve "above" neck block

• Nestle between curfed lining, and against neck block

Glue back to sides

Back in frame with turnbuckles if required
If neck block is not perfectly square to centreline, consider attaching a "rudder" (see image below)
Go-bar deck & rods with split-cushion cauls to distribute force

(avoid uneven joins, gaps)

Do a full dry clamp-up first, to check that all join-lines are tight.

Glue soundboard to sides

NB: make sure the sides are square, so that the guitar can sit stable on its sides
Use wedged sticks if required,

to push top part of sides against mould
can't have turnbuckle clamps in mould when gluing top! (or can we? possible if exit stragetgy has been confirmed in advance!
less force will be required, as final shape is fixed by glued-in bottom
we're only "tilting" the sides to their final shape at top
Go-bar deck & rods with split-cushion cauls to distribute force

Another thing to consider:

• since the guitar is resting on its curved back, excessive force
  when fitting soundboard may cause the sides to warp slightly

• consider supporting the sides (with pieces of varying thickness)

Bolt-on neck experiment

• check longitudinal alignment of fingerboard support tray and tongue

• shim / pad / infill as required

Trim overhang carefully with flush-bearing router

• **Climb-cut everything that's "flat"***

• **For the rest, always go "downhill" (towards centreline)

Tear-out is a risk, especially if the bit is dull

(though small tear-outs will be covered by binding)

Make multiple 2mm climb-cut passes
Don't worry about 1-2mm overhang on back, due to curved back

it will be taken care of when cutting binding channels
... actually, when we level any side-waviness, we'll need to sand it back in those areas

Trace, cut and smooth sound hole

Trace outline using template as a guide

Positioning

• outside of hole follows 25mm inside upper bout edge

• inside of hole approaches fretboard by about 25mm (more for bass)

• inside of hole forms a smooth curve with lower bout (below the waist)

• that curve involves a slight angle between the straight sections of each side (hole, bout)

• template may not be 100% accurate to achieve this

(Originally used Dremel with downmill)
Large diameter Forstner bit for initial hole, then small router, then Dremel with mini drum sander
then finish with sandpaper wrapped around PVC pipes of various diameters
Very slight roundover around the hole - large roundovers are harder to French polish

For softer soundboards (especially Huon Pine)

Fit a soundboard protector for much of the rest of the build. It is so easy to scratch and dent!

Bindings

From now on

• Guitar body needs to rest on a towel to prevent scratches and dents

Before routing the binding channels

• Check the sides for any waviness, and level them by aggressive sanding and scraping.

• If not done so already, level access port cover at this time too

• Make sure the area where the neck will be attached is square to the body centre line

• Seal a strip 25mm each side of the bindings edges with shellac (for glued-on neck: except heel-join area)
  This is to prevent glue squeezeout from soaking in, which is otherwise discovered when French polishing, and has to be aggressively sanded back

• For bolt-on neck option, seal a larger area - the only think we need to keep clear of is the bridge!

Doing these steps after attaching the bindings risks having to scrape or sand the bindings too far back, leaving uneven thickness.

Rout binding channels

Sharpen router bit first!
Rout to 3mm inward depth, 8mm downward depth
Use router with vertial sliding jig and rabbet bit w. bearing
NB: take care at the neck/cutaway corner - do not round it over! Keep it square!
NB: also, make absolutely sure the guitar body is straight and secured in the cradle, so the channels are perfectly vertical!
NB: also, check that the router is cutting channels to the full (sideways) depth - make sure the sides are against the roller bearing, and measure depth to confirm 3mm all around

Direction of cuts

• Any cuts along slopes - cut "downwards", (ie, towards waist, towards centre)

• Any other cuts - climb-cut

• After everything is done, go around again in the regular push-cut direction to tidy things up

Tips for building jig

Similar to StewMac vertical sliding jig
use two drawer runners, wheels aligned back-to-front
the assembly turned out a bit heaver (hello over-engineering!), so I use bungy cords to make it easier to use
for the "donut" to allow the jig to "ride" the sloping back edges, I used multiple layers of Perspex expoxied together

Rout (or cut with table saw) a vertical channel along the cutaway-neck "corner"

• This can be done before cutting the binding channels, however the gap must be temporarily filled!
  Doing it now raises no problem cutting the binding channels around the heel, but tear-out is more of a problem!
  Temporarily glue in a piece of sacrificial scap to shore up against tear-out

• Decide on design:
  Wider strip (show face at side, preferred) = best "enclosed" by bindings
  Narrower strip (not preferred = bindings can butt up against it, in which case defer until after attaching bindings)

• 2*2mm isOK but 8x3mm will better match the bindings

• Do not exceed 3mm "thick" - the channel depth must not extend beyond the binding channel!

Make a strip to fill this channel, we will glue it in revealing the neck-tongue pocket
Use same wood as for bindings

Expose neck-tongue pocket and fingerboard support pocket

This must be done after the binding channels are cut, or there will be problems near the heel cap!
Open up a hole in edge with pull-saw
Use flush-cut router bit
Square out and tidy up and with pull-saw, chisels and sandpaper

Glue in the vertical boundary strip along the cutaway-neck "corner"
(Strip and channel may have been cut two steps earlier, otherwise do it now, with anti-tearout measures)
Scrape and sand flush (neck-facing side)
Leave a bit proud on the side-of-body side (so that we can scape/sand flush after attaching the neck)
trim each end flush with the binding channels

Attaching bindings

There is a problem with wooden bindings on a curved-back guitar, and managing it is a work in progress.
Since my design has an accent layer with two types of timber, imperfections are serious, as they cause
the accent layer to visibly wander towards the edge.

Principles to solve this problem

• thinner inner layers conform more easily,

• use a bending iron on the thick outer layer, so that if perfectly conforms to its intended shape at rest.

• make sure curved back profile is smooth, with no "sharp" bends

• most recent iteration:

• side height follows a circular profile along linear body dimension (rather than a spherical back profile).

• the trade-off is a slightly flatter area around the waist, where the sides move closer to the centre.

• choose less-deep bindings, eg 8mm instead of 9mm

• channels need to be perfectly vertical: guitar must be secure in cradle when cutting bindings channels so it doesn't tilt over

• file/sand tilt-bevels (aka fillets) on inside surface at waist, upper bout, horn and cutaway so tilted binding presents a vertical face to glue
  sandpaper and scaper seem to be the best way to do this

• do at least one dry tape-up to test that tilt-bevels are adequate before gluing

My design uses two different timbers to give a "purfling-like" appearance.

Soundboard side

• Lighter-coloured soundboard favours a three-layer plan (dark/light/dark)

• No curvature means far less risk of gaps around waist & cutaway

• Inner layer: dark, 0.6mm

• Middle layer: light: 0.6mm

• Outer layer: dark, 1.8mm

Rounded back

• Darker-coloured back makes a two-layer plan (light/dark) more attractive

• Curvature means we need to file/sand in some tilt bevels at the waist, upper bout, horn and cutaway

• However, if the inner layer is thick enough for those bevels, any gaps will mean we need to pare back the correspondingly-thinner outer layer, not only making the problem very obvious, but also raising the risk of sanding through the outer layer!

• Current working notes...

• Inner layer: light, 0.8mm

• Middle layer: dark, 0.6mm

• Outer layer: dark, 1.6mm

Important: to reduce tilting of bindings due to curved back

• sand away 0.25mm-1mm tilt bevels of lower-inner corners of bindings

• at waist

• at upper bout (non-cutaway side)

• at cutaway outer curve ("horn")

• at cutaway inner curve

Note that although the bevels initially have a curved border, I then attempt to sand the inner surface completely flat.

Fine-tuning tilt-bevels

• It is essential to perform dry tape-ups to ensure there are no gaps.

Clamping method, traditional option

• Titebond

• four stages

• cradle body in half of the solera jig

• use elastic clamping jig (aka B&D vice)

Clamping method, if dry tape-up is perfect

• cut bindings to correct length at tail

• a minimal bead of Titebond in the channel to attempt to seal it from excessive CA soak-through

• redo tape-up

• apply CA glue, enough that it soaks between all layers, but not much further

• four stages is best, non-cutaway first, then trim the neck-block overhang and do the cutaway side

• if glue seeps underneath tape, consider replacing each piece of tape after applying glue

NB: note that in one of the images below, I have used the clamping jig backwards.
This is OK for a small-bodied guitar, but ideally the jig should be the right way round, as shown in the first image.

Scrape bindings flush

The more overhang, the more work!

For the soundboard and back

For the ends that extand up/down past the bottom and soundboard, using a spokeshave can remove material quickly
However, great care must be taken not to dig in, and because there are two layers of binding, this means that some sections cannot be trimmed this way.
The scraper is also susceptible to grain direction, but less seriously.
Spokeshave, then scraper, then sandpaper.

For the sides

Wrap the Shinto saw-rasp tip with two layers of masking tape
Hold it by the tip so we can use pull-strokes
The masking tape protects the sides from being scratched
Use this for coarse material removal
Scraping the Shinto longituninally along the bindings can weaken the timber, making subsequent filing/sanding easier
After the Shinto, sandpaper
After sandpaper, the scraper with a fresh burr!

Shallac Test

Apply more shellac around the joins, this serves two purposes:

• to reveal any glue that needs more sanding,

• to reveal any scratches from the Shinto... that need more sanding

• it is much better to do this now that after starting French polishing

If the bindings have an accent layer

File or cut a small notch at the heel-cutaway 90-degree join, where the accent layer buts onto the heel
This void can then be filled (matching dark bindings timber), giving a concentric or nested appearance
For glued-in neck option, clay-based filler such as Timbermate is adequare
For bolt-on neck option, a mixture of glue and sawdust is recommended, as it forms part of an exposed edge
See photos below

Fill any major voids in body

Ignore gaps smaller than those to be dealt with when grain-filling
Find them all
Glue and sawdust, or coloured hard-setting putty

Glue and sawdust is difficult to remove later...

Very annoying to keep finding one more when it's time for finishing
Sand adequately (important if using glue and sawdust, or shellac will reveal pale spots)

Fretboard

Making a fret-position template for the StewMac jig

• Create a table of fret-positions, as well as between-fret distances for double checking

• StewMac website has a good calculator for this

• Use custom jig to hold large (60mm) calipers and length of alumium bar

• Slide calipers to fret positions, scribe line along jaw using compass point

• Use second (normal size) pair of calipers to double check inter-fret distances to avoid "off-by-one" errors

• Use bandsaw to cut slots, with sliding bevel and a piece of masking tape to line up the scribed lines

• For some scale-lengths, the final few frets will have to be cut "from the other end"

• Either re-scribe those lines using caliper jig, or carefully transfer using set square

• When cutting "from other end", don't forget that the slots must be one the other side of the scribed line!

• (Alternatively, a micro table saw with a thin carbide blade can do this more accurately)

• Clean up slots with files / hacksaw blades / sandpaper wrapped around scraper (or other thin piece of metal)

• When using, trim the zero-fret line 0.7mm shorter for better intonation

Bound-neck option

• in my experience, fitting frets on a bound fretboard is more sensitive to too-narrow slots

• it is highly recommended to widen the fret slots with material-removing method (not just stretching the fibres at the surface)

Plan fretboard fret count and width

Width extension ratios (of positions of fret pairs)

6-string / 14th-body-fret: 21 frets

12-string / 14th-body-fret: 21 frets

Bass / 14th-body-fret: 19 frets

Blank lengths

Slotting fingerboards for frets

Use jig & template

(48mm is typical)
Check depth after slotting 0th fret (doesn't matter if it's not right, we're going to cut all the way through on that one)

Bound fretboard option

• If doing this for bolt-on neck option, recommend "understated binding":

• same timber as fretboard,

• no inner accent layer,

• no binding around wave motif at end,

• only benefit is tidier fret-ends.

• Reason: binding has no glued support from below

• Less forgiving if freboard width needs to be adjusted after finalising neck fit

• Wave motif at fretboard end tricky to bind/clamp

• Suggest milling some Jarrah 3mm thick, or Jarrah 2.3 and Celery-top 0.7

• Bend some lengths to match wave motif on bending iron

• Trim fretboard width 4mm thinner (and length 2mm shorter if binding wave motif end)

Trim fingerboard to width

Consider

• offset the sides so the highest part of the curve is slightly toward the treble string

• this will allow the treble string saddle notches to sit a little higher

3mm MDF strip, double-sided sticky tape, bandsaw fence
use 3mm MDF strip, slightly wider than fingerboard
attach fingerboard to strip with double-sided tape
rotate so that cut-line is parallel to one side, slightly "in" from edge
setup bandsaw with fine blade
use bandsaw fence strips slides along
MDF sacrificial backing also prevents tear-out
repeat for other edge
Finish both edges using aluminium straight-edge bar

and double-sided tape-attached sandpaper

Finalise wave motif on fretboard

Freehand draw, rough cut with bandsaw,
progress with belt sander,
finish tight radius with sandpaper wrapped around PVC pipe

Widen all fret slots

Very important for bound-neck option
Quite easily done now
This will reduce the amount of hammering, especially onto an unsupported area of the fretboard
Start by scoring with a compass point
Finish by tapping in a piece of fret wire with the barbs removed
(Alternative: using a fret press in the drill press)

Attach fretboard binding (optional)

• Challenging bending and mitre-work around wave motif!

• Use thicker-than-required binding at sides, and thinner around wave-motif for easier bending

• Next time: cut a rabbet under very end of fretboard, glue in an extension

• ...Binding around wave-motif will therefore more accurately be purfling

Fretboard inlay and side dots

Drizzle super-thin CA to fix

Inlay dots

Forstner bit (using stop-nuts on the drill press to get accurate depths)
To drill the 12th-fret pair without resetting the stop-nuts, shim the edge with a ruler, and don't quite bottom out.

• NB: if following the saddle-balance, offset-fretboard option, take note that each side will be a different thickness

12th-fret pair: edge 5-8mm from fretboard edge, therefore centre is 9-12mm from edge

• If the fretboard is not bound:
  Having them not quite perfectly centred is OK
  Leaving a bit more spare width at the bottom edge
  Which we may need to remove when levelling the cutaway-heel join

• If the fretboard is bound:
  Much less wiggle room!

a little CA on top is OK
having to sand them flat is also OK (400)
if hole too deep, shim with little circles of paper - though this can make them sit unsteady
a little sawdust in the holes might be a good idea

Side dots

Dremel drill press with 2mm drill bit and steel-and-aluminium side-dot jig

• The top of the jog is painted black to more easily see marks through the drill-bit hole

• NB: if following the saddle-balance, offset-fretboard option, the bass side of the fretboard will be thinner, and will thus require shimming.

• This is because it places the hold a fixed distance from the underside of the fretboard
  A piece of cardboard, possibly tweaked with a layer of masking tape, will probably suffice.

Clamp fretboard to a piece of thick timber to keep the upright square, and the top horizontal
12th-fret pair: about 10-12mm spacing (4mm for fretless)

Finalise neck carving, now we have fingerboard to size

trace fingerboard onto top of neck
lots of fiddly work
scraper useful
coordinate neck width with body (but leave a little bit proud both sides if possible)
finalise headstock shape with spindle of belt sander

Make index pins for fretboard

cut the heads off two small nails, leaving 11mm and 15mm
nail them into top of neck, short one near nut, longer one near heel
leave 3mm sticking out
file those stumps to sharp points with a file
impale the fretboard over the indexing spikes, hammer/clamp if needed

Progress trimming neck to fit fretboard

concentrate on the top side
leave some material to be removed on the lower side (cutaway)
(This will make cutting the neck-tongue slot a bit easier)
Also finish the neck-headstock transition now that the fretboard is in place

Drill tuner holes in headstock

My choice of tuners

clamp drilled headstock template to headstock
get a nail, wrap with masking tape if diameter not correct
poke through template holes to make marks in headstock

Easy method

• Drill holes with Forstner bit (against sacrificial base)

Recommended method

• Set drill press stop nuts so that the Forstner bit spike just pokes through the back

• The hole stops about 1mm before the other side

• Turn piece around and finish from the back, using the hole the spike made to guide the bit

• This give perfectly clean holes on both sides

Hole diameter

Fitting neck to body

Ideal bridge height

• For an acoustic guitar the bridge should be ~9mm

• The saddle should extend about 4mm above this (in the middle), giving a total string height of 13mm (0.5")

• The saddle slot should be at least 5mm deep, aiming for "two thirds of the saddle in the slot"

• Opinion seems to be the neck angle should aim for a ruler along the frets having 0.5..1.6mm of clearance above the bridge (without saddle)

• However, there are two complications:

• For basses, action at the 12th is generally 1mm higher

• For fretted instruments, we will be doing this before installing the frets

• Therefore, taking an average fret height of 1.2 (from 149/152/47095/47104 fretwire):

• NB: these targets depend on the fretboard being perfectly flat along its entire length, including the section on the guitar body.

• *Actual experience with fretless basses indicates that a 2mm undershoot is better

• Assuming:
  6mm fingerboard depth (pre-frets),
  9mm bridge height,
  projected neck-body line should stand off bridge position by 2.5mm
  the the A-frame soundboard curvature delivers something pretty close to this with a perfectly straight neck-body transition

Estimate neck angle

• Ideally, the heel face will be cut perfectly square. Check that it is

• Ideally, the soundboard will have a slight curve due to the curved A-frame bracing

• Ideally, the neck block will be perfectly perpendicular

• Ideally, we want a perfectly straight line across the junction of the neck and soundboard

• Although the curved soundboard will fall away from this line (allowing bridge height), the fingerboard should be able to be perfectly straight

• Therefore, we will need to sand a slight angle into the heel face

Cutting neck angle (previous method)

• Line up the neck with the body to get a rough estimate of the required angle

• Sand almost that estimated angle into the heel face using band sander, the tidy it up with a strip of sandpaper attached to a board

• This will also dress the face, which will be rough from being cut on the bandsaw

• Take care not to crown it

Cutting neck angle (current method)

• Make sure length of neck is almost right, so plane only has to change angle, not do serious shortening

• Use a No. 8 handplane and custom shooting board with adjustable fence to get 90% there

• A No. 7 could also be used, but will be too narrow for 5-string basses

• The heel has a complex cavity for fingerboard support - this needs to be packed

• The adjustable fence controls the longitudinal angle

• Control lateral angle by raising or lowering the bridge against the fence, then clamp

• Measure, don't calculate

• Take the finest shavings possible, taking care to avoid end-grain tearing

• Multiple passes may be required

• If required, the final part of fitting can be done with the sanding board, "leaning into" the corner or end that needs most taken off

Cut slot in heel for neck-tongue

Use table saw in dado mode, being very careful not to make it too loose
Verticality: if the heel surface is not perpendicular to the body centre line, shim one side with masking tape
Depth: so that there is about 1-2mm of space when tongue is fitted

(Measure tongue extenstion from neck-block assembly in body)
(Be careful not to hit the steel end-nut of the truss rod)

Position (lateral): very careful,

we have already almost finished trimming the top side of neck & fretboard
we will be sanding cutaway portion of neck and body flush

After cutting slot, lower portion of heel will be very fragile

It will be held together by as little as 3mm of edgewise grain
Glue a small block in the bottom portion of the slot, corresponding to the filled-in area at the bottom of the neck-block mortise

Preparing to fit neck to body

Do as much as possible at this step, as adjusting the heel-face is easier
Neck tongue should now fit into body and neck
Fit to body, use M6 60mm furniture screws, screwed in all the way

Fit neck, check three alignments

• Side-to-side (yaw) angle - are the three centres (tail, neck-join, nut) in line?

• Up-and-down (pitch) angle - zero in on the neck angle previously estimated, we want a perfectly straight line where the fretboard spans the neck and body
  Note that since the soundboard is slightly curved, there will be a small amount of "fall away" at the highest frets.

• Rotational (roll) angle - does the "roll" axis neck align with the body?

Fix the first two by sanding the butt-end of the neck
Fix the third by shaving and doing shave 'n' shim on the neck tenon (remove from body)
Mark correct height of neck-tongue in neck slot

(there is +/- 2mm of play due to the neck-block slots, so mark the centre position)

Now that we know more about the join, so a little bit more on the bottom side of the neck if required
We want to minimise the amount of neck to remove once fretboard is attached

Especially around the heel

Use neck tongue and do as much as possible on the heel-cutaway join

but leave a tiny bit of the vertical boundary strip proud so that we can sand it smooth after joining

Plan and partially cut heel cap

Option (a) (preferred)

trim heel to an angle matching curved back
heel cap will be even thickness
when gluing on fretboard, temporarily attach a wedge (nails? screws?)
to make a flat surface on the end of the heel to make clamping easier

Option (b)

leave heel straight, heel cap will be a wedge
in this case, clamping is simple when gluing on fretboard

In both cases, plan for it to be flush with back

But leave it proud for now
Don't attach yet

Glue neck-tenon into neck

Use the neck-height mark made two steps up

(doesn't have to be exact, due to the +/- 2mm of play)

Leave two furniture bolts in the tongue, to prevent glue getting into nut threads

Trim the tips off if there is not enough room when fully screwed in
(when doing a dry fit)

Tongue fit should be not too firm, glue will take up space and also swell the wood
Clamping is hard, be careful if you clamp the heel that it stays square in place
Some side clamping is good, but not too tight, don't want to split the grain
Clean off all squeeze out (especially for a glued-in neck)

Take note of the thickness of the thickness of the backing plate

• This will needed to trim the clamping bolts to correct length when attaching the neck

Attach neck to body

This means one of two things

• For a glued-in neck, that means gluing in the neck

• For the bolt-on neck option, it just means... bolting on the neck

If not done yet, file the notch into the lighter-coloured bindings layer to make everything look concentric/nested (see notes/images in Bindings section)
Determine correct length and trim furniture bolts for clamping

• They need to engage with embedded nuts, but not extend further to press against heel

Use furniture bolts to clamp, but make sure neck height is right before tightening

In both cases

• Clamp neck to body and check all aligments

• Angles can be adjusted by the channeled sanding jig (see image below)

• Take care of neck-action (bridge height) angle first,

• Then adjust lateral neck angle

• In both cases, use oven paper to cover the sandpaper where do not want material removed

• Very minor adjustments can also be made by sanding the heel-end of the body

If gluing

• Clean of all squeeze out very carefully

• Decide whether to remove furniture bolts when dry
  the slots are probably better aesthetically
  but there's no harm in leaving them in place (though it might give the incorrect impression that the neck is removable)

Attend to any coarse levelling required at neck-cutaway join

(will finalise it in the next step)
sand down any remaining proud amount of vertical boundary strip

Temporarily attach fretboard to neck

• Since we're following the Finish soundboard first option, just press it down onto the index pins for alignment.
  Use clamps if the index pins don't have enough friction to keep it secure

Ensure neck and body under fretboard is ruler-flat
This may require minor sanding, in which case the index pins should be removed (and replaced afterwards)
Heel is either still flat, or has temporary angled block screwed on to make clamping heel area easier

Finalise fretboard, neck and heel fit

• Some cleanup will still be required after fretboard is glued on.

• Mark the centreline / fullscale line point

• Extend that line outwards to string-spacing width at bridge

• Use two rulers to extend the fretboard edges, checking that they symmetrically "bracket" this line

• Bear in mind that when neck is attached, some re-profiling of neck/fretboard edges might be required

• Level heel-cutaway transition

• Depending on how perfectly the heel joins the body, levelling might "eat into" the side of the fretboard

• If it's less than 0.5mm that's OK, at this stage there is usually about that much "extra"

• Remove it and re-flatten that edge against aluminium section sanding bar

• re-check symmetry, we don't want the centreline to wander (<1mm is OK)

• sand and scrape so fretboard-neck join is near-perfect, which will leave a fragile sharp edge after fingerboard is removed...

Bolt-on neck option: fit fretboard support extension

• There may be some lateral wander, existing support piece may require adjustment

• Make sure the support extension fits, ready for gluing to the heel and fretboard

• Pad out the perimeter so the extension is centred in the pocket

• Level the fretboard support extension for a perfectly straight line
  NB: sadly, this levelling does not take the thickness of soundboard finish into account
  We will have to create some very thin shims to correct for this later

• Important: plan position of support extension bolt and nut: position it forward so that it cannot interfere with the two neck-tenon bolts

• Drill 6.5mm hole into fretboard support extension, then into neck block tray

• Expand that hole in the fretboard support extension to 9mm, and screw in a threated insert nut
  Use a piece of scrap with a 6.5mm hole and an M6 nut to keep the threaded insert square to the fretboard support extension
  The butt-end will threaded insert will be slightly proud - either file it down or carefully enlarge the top end of the hole

• Glue support extension to neck while attached to body:
  (Original plan was to glue fretboard, neck and support extension in one step, but that can result in an incorrect angle for the support extension)

• Apply masking tape or candle-wax to neck-block surfaces that might be exposed to squeeze-out

• Attach neck and tighten tenon-bolts, checking vertical alignment for flush neck-body transition

• Glue neck support piece, clamping to required alignment

• If desired, fill in any voids on the top side of the heel area

• Last chance to do any required shimming and levelling...

Bolt-on neck option: glue on fretboard

• Detach neck and glue on fretboard, using the inverse-curve clamping caul to get hairline joins when the neck meets the fingerboard

• Cut a piece of M6 bolt, screw it into the fretboard support extension threaded insert bolt so it sticks down.
  It will be secured from below with either a wingnut or a fancy knurled nut.
  (Later, secure that bolt shaft with Locktite)

• Attach the neck to the body, testing the two tensioning bolts and the fretboard support extension nut

For glued-in neck: attach a short, bevelled surrogate fretboard to neck to protect the fragile, newly-created sharp edges

• (not necessary for bolt-on neck option as we will be gluing fretboard almost immediately)

• have it stop just short of the body-fret (so it won't interfere when French polishing soundboard)

• also, bevelled down to an edge at that end (same reason)

• a little overhang at each side

• screwed into the top of the neck

• all the handling will round over those sharp edges, resulting in a gap along the fingerboard-neck join line

Making bridge

Decide on saddle blank thickness

Mark full-scale line on soundboard

Both methods

• Finalise bridge height as per "Ideal bridge height", above

• Ensure fret board is perfectly flat (a tiny amount of upper-fret fall-away is OK)

• Cut and mill blank : 152 x 50mm x 1mm more than required depth
  (we are going to scallop the underside of the bridge)

Historic method: making bridge by hand

Plan compensation:

Saddle slot is 4.5mm wide
6-string guitars, ~55mm string spacing at saddle

compensation is x..x+3

• pins parallel to saddle

• 12mm back from slot edge

Bass guitars, ~58mm string spacing at saddle

compensation is x..x+4

• pins parallel to saddle

• 17mm back from slot edge

12-string guitars, ~60mm string spacing at saddle

compensation is x...x+2 (need to carve individual intonation notches)

• First row 8mm back from low-E bridge slot edge

• Second row 20mm back from low-E bridge slot edge

Option #1 - cut saddle slot with table saw, dado-style

Extend compensated saddle line to ends of bridge blank
Current blade cuts 2.6mm slots, so multiple passes to "creep up" on saddle thickness
Use a shim block to offset blank from vertical to get compensation angle
After cutting slot, glue in strips of wood to fill spaces on each side

Option #2 - making the slot on a laminated bridge by using two top-layer pieces

Laminate and mill the bottom layer to required thickness (x-4mm)
Mill the top layer to 4-5mm (corresponding to saddle slot depth)
Mill a strip of timber to the same thickness as saddle to make the two slot-infills at each end

• laminate using a candlewax-covered saddle blank and a slotted clamping caul

• remove saddle blank after about an hour

• carefully clean all squeeze-out from inside of slot

Current method: using CNC rounter to making bridge

• CNC carved bridge in 10mm blank

• We cut the saddle slot with a separate bit, option or straight or split saddle

• Cut well outside outline with bandsaw (to avoid underside tear-out)

• Finish perimeter with band sander

• Clean up fuzzies and contour lines by hand-sanding

• Later, we will scallop it to 9mm in centre, 3mm at wings, giving a weight of ~35g

• With correct neck, a ruler, pre-frets, should just touches the edge of the bridge

• Later, when frets installed, a ruler should overshoot bridge by about 1mm,

• For split saddle option, it is highly recommended to fit saddle blank now,
  so that when we get to setup, we only need to deal with a little bit of shellac in the slot

Drill/enlarge bridge pin holes

Hole diameters

For handmade bridge with aluminium template

• easiest method - clamp template to bridge

• drill taking care not to enlarge template holes

• very slight counter sink for bridge pin shoulders

Handmade bridge if not using a template

• Mark positions using compass point

• Then pilot hole punch

• Drill in Dremel drill press, 3mm bit, 3mm deep
  Position by hand with power off, hold down, drill

• Use countersink bit to widen shallow holes
  so larger drill bit will seat correctly

• see diameter table above

• very slight counter sink for bridge pin shoulders

CNC bridge

• CNC bridge have starter holes, they just need to be drilled all the way through

For basses

• NB: Spotted Gum is liable to tear when starting the hole, start with countersunk bit to avoid this

Scallop underside of bridge

Concave transverse bow matching (and slightly exceeding) bow in soundboard: 0.5mm?
Then also a "cavity" scallop (0.2mm?)
Reason: so that we can clamp using bolts through the bridge pin holes

The complex concave curves will serve two purposes

• "pull" the soundboard into a slight convex shape

• Have "sharper" join-lines around the perimeter

Plan bridge placement

Find and mark lateral placement first

• lay a metre rule along each side of the fretboard

• should be ~2mm outside of the outer bridge pin holes

• equalised = centred laterally

Use StewMac Saddlematic for lengthwise placement

• Wait a minute - we have no frets!

• take a length of fretwire (doesn't even need to be radiused)

• file off the barbs

• hammer into the 12th fret slot

• remove later

Adjust bridge slot spikes/screws

choose compensation amounts for low and high strings
set pin width to bridge string spacing
subtract half of saddle thickness

NB: VERY important!!!

• We have trimmed the fretboard so the zero-first fret interval is shorter!

• This means the normal method of using the StewMac Saddlematic will give incorrect results!

• Measure the zero-first interval, adjust Saddlematic to add whatever we trimmed off

• Alternatively, use a shim at nut-end the same thickness we trimmed off

Bass

• String spacing at saddle: 58

• Compensation 3.2..7.2

• Saddle width 3, so subtract 1.5

• Offsets from full scale to inner saddle edge: 1.7, 5.7

• Final measurements should be (for 34" scale)
  863.6 + 1.7 = 865.3
  863.6 + 5.7 = 869.3
  (Worrying that this will not be enough if the action is adequately high)

6-string, straight bridge

• String spacing at saddle: 55

• Compensation 2.3..5.3

• Saddle width 2.5: subtract 1.25
  Offsets from full scale to inner saddle edge: 1.1, 4.1

• Saddle width 3.0: so subtract 1.5
  Offsets from full scale to inner saddle edge: 0.8, 3.8

• Final measurements should be (for 25.5" scale, 2.5mm brige)
  647.7 + 1.1 = 648.75 (648.5 for 3mm bridge)
  647.7 + 4.1 = 651.75 (651.5 for 3mm bridge)

• for 24.75" scale
  628.7 + 1.1 = 629.8 (629.55 for 3mm bridge)
  628.7 + 4.1 = 632.8 (632.55 for 3mm bridge)

6-string, split bridge

• String spacing at saddle: 55

• Compensation 2.1..5.4

• Saddle width 3.0: so subtract 1.5
  Offsets from full scale to inner saddle edge: 0.6, 3.9

• Final measurements should be (for 25.5" scale, 3mm bridge)
  647.7 + 0.6 = 648.3
  647.7 + 3.9 = 651.6

• for 24.75" scale
  628.7 + 0.6 = 629.3
  628.7 + 3.9 = 632.6

• (Bridge edge should be perpendicular to centre line)

12-string

• String spacing at saddle: 60

• Compensation 2.25..4.25

• Saddle width 3.5, so subtract 1.75

• Offsets from full scale to inner saddle edge: 0.5, 2.5

• (Cannot get StewMac pins that close, consider using outer edge)

• Final measurements should be (for 25.5" scale)
  647.7 + 0.5 = 648.2
  647.7 + 2.5 = 650.2

• for 24.75" scale
  628.7 + 0.5 = 629.2
  628.7 + 2.5 = 631.2

Drill bridge pin holes in body

• Put a layer of masking tape down so we can trace bridge position with pencil

• Position bridge and trace around perimeter with a sharp pencil

• Overlay a modest amount of double-sided tape

• Note: the aim of the tape is to keep the bridge steady while we attach the C-clamps.
  The aim of the C-clamps is to keep the bridge steady while disturbing it with the drill.
  Then we need to remove the bridge without damaging the soundboard.
  This has proved tricky in the past, which is why we now do this step earlier.

• Place some upside-down fibreglass-reinforced tape near ends, to assist when removing the bridge.

• Position bridge in the exact position of the traced outline and press down.
  Use the peeled off wax paper to fine tune position before sliding it away and pressing down

• Attach and tighten the C-clamps

• Using an imperial drill bit just smaller than the bridge holes as a punch,
  make starter indentations by tapping gently while rotating the bit between hits.
  For guitar (5mm bridge holes), use a 3/16" bit
  For bass (8mm bridge holes), use a 5/16" bit

• Using that same bit, drill starter indentations only in the two innermost holes
  For guitars, it might be possible to drill the four innermost holes.
  The C-clamps mean we cannot drill the outermost holes
  The slightly smaller drill bit minimises the risk of the bridge moving.

• Important: change drill bit to smaller (body) diameter!

• Remove the C-clamps, finish drilling the innermost holes, holding some scrap underneath for a clean exit-wound.

• If really confident in the steadiness of the tape, drill all holes...
  Otherwise, bolt down the bridge with 3/16" countersunk bolts (top) and wingnuts (underneath)
  NB: don't over-tighten, or there'll be mismatched counter-sinking to fix!

• Finally drill the outermost holes

• Optional: check using actual bridge pins, which of the holes are accurate enough to repeat exact positioning of bridge later

Alternative approach

• Use the two C-clamps to make sure double-sided sticky tape is secure

• Move the clamps back and forth to make room to drill each hole, making sure one is tight before moving the other

French polishing soundboard

Decide whether to French polish soundboard first

• Yes for glue-in neck

• No for bolt-on neck option

Sand soundboard to final finish-ready smoothness

Round-over bindings (soundboard side)
Decide whether grain filling is to be done

• NB: The answer is yes it must be done, at the very least to the sides

If using grain-filling

• Position bridge, mask bridge and fretboard with magic tape (as per details in following sections)

• Apply grain filler

• Remove mask, sand filler down to wood

If feeling on a roll, do back and sides as well, though stay away from heel cap area

Mask bridge position & fretboard for French polishing

Reposition bridge

• if all is going well, bridge pins will suffice

• double-check with position with rulers

Put strips of Scotch/magic/invisible stickytape where bridge will be

But first, put a piece of paper down in the middle - to make removal easier when French polishing is complete
fold over ends of tape- starting a peel is difficult
since Scotch tape lifts fibres when peeled off, don't rub it down hard

Position bridge

if bridge pins are not 100% accurate and stable, use the bridge clamping jig (see notes on attaching bridge, below)
trace around bridge perimeter with a sharp pencil (can draw on Scotch tape)
NB: on softer soundboards like Huon pine, the pencil will score the timber through the tape.

• try an additional layer of paper attached with double-sided tape.

attach inner bridge mask (aluminium template 1.0mm inside the bridge perimeter)

• use bolts and wingnuts

• position so that it is perfectly centred 1.0mm inside the traced outline

• if it isn't perfect (bridge has been sanded to a slightly different shape), reposition the template for each line segment

• use this template to cut the outline - inside the bridge position

• shellac remains rough in sticky tape edge's lee

peel away excess tape, leaving bridge area masked
make sure tape is firmly attached (ok to rub down now, this area will be covered by bridge)

• put an extra piece to cover the holes used to bolt down the inner mask template

Glued-in neck option: repeat steps for area of fretboard that is over body

Historical note:
Before the Finish soundboard first option, at this stage we would:

• simply mask entire fretboard

French polish soundboard

• NB: make sure rubber surface is clean - fresh cloth recommended

• French polish the soundboard only - long uninterrupted strokes for the win

• After the sealing / flood-fill stage, some timbers may exhibit raised grain
  - do an additional levelling step at this stage to address this if needed

• NB: sticky tape in the two masks may become lose and shed flakes of shellac, which then adhere to the guitar and need to be sanded down (1200 sandpaper & oil)

• See French polishing notes below

• Stop before "spiriting off" stage, wait until finishing rest of guitar

• When complete, leave on all tape masking for now

Complete all construction steps deferred due to the Finish soundboard first option

Make truss rod cover and pickguard (if required)

Truss rod cover may need to have an indentation in the bottom singe truss rod nut pokes up a bit

• Initial design was a simple ogival arch

• I now have a more complex narrower design that can be removed while the strings are tensioned up

Mill some fingerboard/bridge wood

Truss rod cover

Truss rod nut almost certainly protrudes above headstock
Cross-ply lamination is a good idea, though it can make the stock curve
Mill (and optionally laminate) to required width
(3mm seems to be pretty common, allowing 2mm truss rod nut protrusion)
We used to do this by hand, we now use the CNC router
Drill / excavate a furrow in the underside, for truss rod nut to fit into.
If not using CNC rounter, a Dremel spindle sander is good for this.
Cut a 14-degree under-bevel so it butts up nicely with the back of the nut

Pickguard

Rip to 70mm (GP), 65mm (parlour), (generally don't do bass)
Mill to 2.5mm

Shape, sand, fill grain with Timbermate or Feast Watson sanding sealer, sand

Glued-in neck option: glue fretboard to neck

• (Already done for bolt-on neck option)

NB: do a dry run clamping first, for the following reason:

• check for any gaps

• final check fingerboard width is correct

Remove fretboard tape masking from soundboard
Everybody on the internet keeps glue off the truss rod,

• This makes sense for exposed-rod designs

• It makes no sense at all for the Martin enclosed channel model

• A small piece over the truss rod nut might be a good idea though

Use inverse radius dual-curved clamping caul, it makes it a breeze
Clean off all squeeze-out carefully with moist cloth or kitchen wipe
NB: use more clamps than in image below

Attend to any minor sanding of the fretboard-neck join

• Most of the fitting was done earlier, we're really just finessing the glue joins

• Finalise smoothing the heel-cutaway transition

Attach heel cap

Clamp with a regular clamp and index pins
(If neck is glued in, can also use semicircle-cutout clamping caul with bungy cord)
Finish carving still-proud transition to back and heel

Bolt-on neck option

• Sand a tiny heirloom fit round-over along all heel-body join edges

• This will legitemise any miniscule unevenness due to the neck not being glued in

Final sanding, rounding over bindings edges, void-and-grain-fillings

Final check for gaps - fill with glue and appropriate sawdust (or other product)

Grain-filling

• Timbermate water-based filler - various colours - diluted with water
  - works-ish, but balance between under- and over-sanding is very fine

• Feast Watson sanding sealer?
  - works-ish, but leaves some unfilled micro-voids. Over-sanded?

• At a bare minimum, grain-fill the sides. The back can usually be managed with shellac,
  and the soundboard (on which we like thinner finish) may have its own "levelling raised grain" measures later.
  If using commercial sanding sealer, don't sand immediately - it likes a longer cure time.

• The sides may still be marked with shellac, don't fret too much.
  (Very dark areas probably indicate inadequate sanding.)
  Putting sanding sealer over modest shellac marks is quite OK.

Installing frets

My fretwire choices

Glued-in neck option

• we have to install and dress the frets without damaging the soundboard!

Bolt-on neck option

• we can install and dress the frets on the detached neck! (w00t!)

Important (if glued-in neck option)

• Before installing frets, tape two pieces of cardboard
  to the body where the fretboard is glued to it.

• Do not rely on masking tape, even multiple layers.

• When snipping fret ends, the pieces will fly off with great force,
  chipping the soundboard wood (or the finished surface).

• Make sure the cardboard is sealed around all edges,
  to prevent metal filings from finding their way underneath.

Radius sanding block says 11" (from 22" cymbal),

better to bend frets to a tighter radius(ie, 16" cymbal or 14" snare)
I hgave also tried a 10" radius, but hammering approach must be different (see below)

My bending wheel is not perfectly even, the remedy is to keep removing fretwire

and reinserting with crank at different clock positions

• Multiple passes at different clock positions

• Turning fretwire end-on-end each pass

• Each pass goes all the way (piece comes out of machine each time)

After cutting fretwire into lengths

• dull any sharp edges, so as not to cut fingers while hammering

Fret slots are too tight

StuMac recommends against widening them,

promoting a barb-shaving device

I got good results by dragging a compass spike along them

it doesn't remove wood, just stretches the slot
BUT... be very careful it doesn't jump out of the slot and scratch the fretboard!

Ben from Crimson Custom Guitars uses a triangular file

Fret slots are too tight (level boss version)

For bound-neck option, I have found that installing frets requires a lot more force
This may be caused by the fact that the slots are "fully enclosed"
Solution to this is a work in progress

Bound fretboard:

• slots need to be cleaned

• a box-cutter knife blade with the sharp section ground off, can be useful (see image)

Hammering works best with a radiused, hardwood, end-grain caul

Tap one end in, not fully
Work towards middle,
Then other end
Then use hammering caul to get it fully seated
NB: if bending frets to a 10" radius, start at one end, then middle, then other end

Be very gentle when hammering over body (glued-in neck option)

• Considing using an adjustable support strut underneath soundboard

Use rockers to make sure each fret is perfectly seated along its length
The use of glue on virgin slots (widened or otherwise) is debated

I have tried several ways of using CA, without satisfaction
My preferred method is to spread a small amount of some Titebond over the open slot before hammering

Snip off fret ends

• Just in case the cardboard is not adequate, rest scraper against edge of fretboard for extra protection.

File fret ends vertically level using vertical file-holder jig with bevel

• NB: ensure bevel sits on frets, so that file stays perfectly vertical
  and doesn't cut into side of fretboard

• be very careful not to slip and mark frets or sides of fretboard

File 35 degree bevel using 35 degree jig

• be very careful not to slip and mark frets

Check that the fret tops are perfectly level

• While filing the ends, any vertical bumps indicate high frets

• In some cases, imperfectly seated frets can be fixed with the fretting hammer

• In others, the aluminium sanding bar, with very fine grit sandpaper, will be needed

• If sanding has been done, re-crown the affected frets with crowning file

Fret-end dressing

• This for semi-hemispherical fret ends that look (and feel) so nice...

• Using flat-bottomed file, grind in circular end-profile from above

• This may leave "razor-blade points" at each corner, as we were filing in from the side

• Remove (or almost remove) those points by filing from above very gently to avoid filing down the fretboard

• With fret-crowning file, round over the fret ends from above, also putting in some side-to-side and rocking motion

• Coarse steel wool, first across the fret ends, then along the edges of the neck

• Frantically try to improve things with 1200 sandpaper, more steel wool, Fret Erasers etc

French polish rest of guitar

Before beginning

• Double-check access port cover is level

• Remove access port cover, deepen countersink holes for screws if sanding has left them too shallow (annoying to do this after French polishing it)

Bolt-on neck option

• Follow "French polish soundboard" section above, especially the bits about masking the bridge position

Tape off fretboard with masking tape

leave most of the sides exposed
this will allow the shellac-lemon-oil transition to be more easily sanded down

Finalise filling grain, sanding etc.

Prepeare shellac

* Three-pound cut

50g flakes, 140ml methylated spirits
Industrial methylated spirits, or dry normal methds with oven-dried tapioca
Mix fresh, some days to dissolve completely, filter if any sediment

Current French polishing strategy

• seal / flood full / initial build with waxed shellac for best colour

• when colour is good, switch to unwaxed shellac for better gloss and sandability

• use a transitional rubber first, so the unwaxed rubber can stay clean

• when levelling unwaxed shellac (or repairs down the track), less risk of ending up with uneven colouring

Apply finish to guitar, bridge, truss rod cover and pickguard (if there is one)
Seal first - use thinner cut, cloth or brush,

don't use a rubber that has seen oil when sealing

NB: immediately after sealing, check for inadequately sanded scratches, and fix them!

Build up sessions
Level micro bumps with 1200 sandpaper + oil

be very careful not do break through finish layer - it is very soft when being worked
declog sandpaper with clean cloth

Optional: cut to matt with 1500, avoiding edges

For a deep, gloss finish, this can be done twice

Pay attention to edges around soundboard:

• since that was done in an earlier session, there might be some unevenness

• can be sanded down with 1200 + oil

Difficult area (glued-in neck option): neck to upper-side join

• use pointed pad to get into corner

Spiriting off

• consider postponing soundboard until bridge is attached

• separate rubber

• alcohol only, very lightly charged

• no oil - the point is to remove the oil

• also remove swirl lines (and put in much, much finer ones)

• should bring up gloss

• need to apply some pressure

• multiple sessions to avoid it starting to grab

Final steps?

• As with spiriting off, consider postponing soundboard until bridge is attached

• Finest car polish??? With ultra-fine cutting compound.

• Must wait a week, so that polish is completely dry & hard

• Wax / liquid furniture polish???

• make sure it is dry so it doesn't pick up fibres

Be very careful of the face that rests on the towel

Remove masking from fretboard and finesse fretboard-shallac transition

• use 350 grit sandpaper to "bevel" the portion of shellac that is on the fretboard

• be careful not to touch the actual neck

• apply lemon oil to the fretboard when done

• if the shallac and/or neck join transition is still troublesome to feel...

• ... try 1200 sandpaper + oil, minimising the amount of neck touched,

• ... a little bit of auto polish afterwards if required

Attach bridge

• But first, sand shellac from inside edges of saddle slot, so that saddle blank fits in firmly but not too tightly

• Don't do this until shellac finish on bridge is hard.
  Masking tape will lift incompletely-cured shellac, and the clamping bolts/caul will deform/mark it.

• Use appropriate drill bit to clean up bridge pin holes after finishing

• Remove masking tape from bridge position on soundboard

• attach the outer bridge mask (aluminium template 0.5mm inside the bridge perimeter)

• position some pieces of masking tape at an even distance (1.0mm?) from the shellac edge

• bolt in place and position it so that it is evenly balanced - use masking tape markers, as it will obscure the border

• use it as a template to trim away the uneven "ridge" shellac around the perimeter

Glue in bridge using bridge clamping jig

• make sure aluminium under-bracket matches scalloped curve of the underside of bridge

• resulting compression should apply enough pressure to the bridge "wings"

• However, small pieces of 6mm MDF can be inserted between jig and wings for additional pressure

After glue is dry, remaining hole(s) can be drilled if not done so already

• Need to wait until clamping bolts are removed so a piece of scrap can be held underneath

Ream bridge pin holes to size

• shoulder rings underneath heads should nestle into the countersunk rim

• After getting one right, use masking tape around reamer

Bolt-on neck option

• unfortunately, we levelled the fingerboard extension support before applying finishing to the soundboard

• if we tighten the neck support nut, it will stress the fingerboard-neck joint,
  and also dig the edges of the fingerboard into the soft soundboard, flaking the finish

• to correct for this, we need to create some very thin shims, and glue them in

• attach neck, check angle - remember for guitars we want to overshoot bridge by 0.5..1.6mm

• check if frets are perfectly level (at least until about the 16th fret)

• if not level with aluminim sanding bar, then re-crown

Any finishing to... finish?

• If spriting off / car polish / firniture polish was deferred do that now

Attach tuners and fit Straplok

Tuners - duh

• But... use a reamer to gently remove any shellac that found its way into the holes, otherwise they will be too tight

• Then, when drilling the screw holes, start with a 2.5mm bit (to find centre), then finish with 1.5mm

Staplock tail hole: also duh

Staplock neck hole

Use strap button support glued in after fitting back to sides
Drill hole in body (masking tape)
27mm up from neck, centred
Bolt in place

Setup

Cut nut to rough shape

• Mark which side of nut is "inward facing"

• Start with the nut profile about 2.25mm above the fretboard (we'll be cutting it down later)

• Rough in with belt sander, then smooth using neck radius block

• Now is a good time to angle the top of the nut so that it is about halfway to the headstock angle. This will make it easier to cut slots that provide a clean break angle for the strings, and avoid "sitar buzz"

• For a 6mm nut, a fall of 1mm represents 9.5 degrees, which is pretty good (headstock is 14)

• Leave sides a bit proud so they can be blended into neck and truss rod cover (if it reaches the sides)

• Mark neck edges and centreline (eventual one will be different)

• Mark low-E position 0.5*nut-string-spacing up from centre, then the rest using the tables below

• (Alternatively, use a string-spacing steel ruler/template)

• Cut slots about 0.5mm deep (we'll be deepening those later too)

• Slots should slope/curve down towards the tuners

6-string (equal centers)

6-string (hybrid-proportional - recommended)

12-string

Bass (equal centres)

Bass (hybrid-proportional - recommended)

Bass nut edge clearance (space between outside of nut and edge of strings)

E string half-diameter = 1.4mm
G string half-diameter = 0.7mm
Worked example using 42mm nut width and the above spacings and half-diameter approximations

Start work on saddle

Mark which side of saddle is "inward facing"
cut slight radius curve on top of saddle

• Take about 2mm off the bass end, 4mm off the treble, leave the middle alone
  NB: if using asymmetric fretboard radius, take 2mm off treble

• if using neck radius block, use it for smoothing only, saddle radius is a bit different

For split saddle option:

• this is a bit more difficult, as the saddle is in two pieces

• marking the string positions isn't all that hard,
  but making it a nice profile curve requires some estimation

Place in saddle slot, use straightedge to extend fretboard ends to saddle

• mark them and use those marks to find string centre

• (if this clashes with bridge pin holes, split the difference?)

Mark string positions on saddle

(summary table below, or more complete versions in "Making Bridge" section)

Cut very shallow notches - perfectly horizontal

• this is a bit tricker for split saddle option, as the compensation angles are greater

String up guitar

Don't bring it up to pitch - nut and bridge are too high

Get action at nut sorted

For each string

• Press just in front of second fret (or use a capo, carefully)
  (not between second and third, that may "bend" the string up at the first!)

• Check clearance at first fret - want "almost touching"

• Slightly higher for bass strings

• Using shadow of string from desk lamp is useful

• A small USB-recharge torch in a desktop mic stand is even better!

• Cut slots deeper until the file binds,

• Then remove and sand off the top, leaving "semicircle" channels

Use the sliver/shadow method to get first-fret action right

• Position a desk lamp / torch behind and above the neck, at about eye level

• Look for the shadows of the strings,

• More specifically, look for the sliver of light between each string and its shadow

• Deepen the slots until those slivers of light are tiny and uniform

• A combination of parallax, neck radius and different string diamater will mean that the actual gaps will be higher for the bass strings, with an even graduation to lower for the treble strings

For fretless bass, this is not possible as there are no frets!

• Use feeler gauge and aim for 0.5-0.7mm (low E) down to 0.1-0.2mm (G)

• Draw a line on the nut across the top of the fingerboard with a sharp pencil

• E: leave a tiny gap, A: tinier, D: kiss the line, G: go halfway through it

• Double check with feeler gauge, that should get 0.5->0.25mm E->G

Check neck relief

Tune guitar to D (two semitones down)
If the saddle / 12th-fret action isn't ridiculously high, try tuning to E
Measure relief using straight edge (use fret-slotting templates if ruler too long)

Desired relief

• 0.25 to 0.3mm (more for bass is probably OK)

Adjust truss rod if necessary

Get action at 12th fret sorted

Stu Mac recommendations (guitar)

(These seem awfully low for an acoustic)

Some TalkBass forum numbers (bass)

12th fret|3..6mm|

Good initial targets (guitar)

Good initial target (bass)

First fret (pressing 2..3): 0.55mm?

My first fretless: about 3.5mm lowest three strings

G string a bit lower for "mwah", all others higher for clear tone

My first fretted: about 4.0mm all strings

(Probably could gradate just a little)

Check action at 12th fret for each string using action gauge

Use Excel spreadsheet to track, update and recomment how much to remove

Slacken string, remove bridge pin, file notch deeper
Replace bridge pin, tune up, check action
Slacken all strings, remove saddle, sand to a smooth curve connecting shallow notches

Replace saddle, check intonation

If problems, use a small triangular file to cut slanting V-notches to move string pivot forwards or backwards
If any saddle-buzz, dome the contact points (or two 1/3-way V-notches)

Finish and fit nut semi-permanently

Position nut so strings are correctly centred
Mark edges with sharp pencil
Grind / sand / file so the transitions to the neck are flush and smooth
Fix nut with two drops of CA glue (each side of the truss rod nut)

Attach pick guard and truss rod cover

pick guard: double-sided tape (two narrow strips, top and bottom)
truss rod cover: screw(s)

• Current bell-like design can have a single screw 18mm back from point

Pickups

My personal preference is for K&K Pure pickups with no onboard electronics. Since this has very high impedance, recording or playing live will require

• a pedal like the Zoom AC-3/AC-2

• a dedicated acoustic amplifier like those from Boss, Fender, AER, Fishman etc

• going directly into the PA/recording interface, with a DI box if the input if required

Since my guitars have no centre sound hole, installation requires
I have built some aluminium installation guides. Note the notches for the wires to slide through, otherwise they'll be permanently "threaded".

The steps are

• remove access panel cover, remove strings, put into the two bridge pins

• check fit of alminium guide, it should fit up against

• cut some bamboo satay skewers to use as clamps, go-bar style

• put some wax around the edges of the aluminium guide so superglue squeeze out won't glue it in place

• stick the guide to the bridge plate with double-sided sticky tape

• position the pickup so the individual piezo elements are accessible and correctly aligned

• glue each element separately, as follows

• apply some superglue gel to the bridge plate, in the middle of the first guide hole

• position the corresponding pickup element in the guide hole and clamp with a satay skewer

• do the same for each remaining pickup elements

• when the glue has set, detach the guide and unthread from the pickup wires

Drilling for the socket

Measure from the edge of the access panel

Hardware information

My choice for tuners

My choice for frets

Build history

Build #1 - fretless bass

• most of 2020

• over-braced (25++mm A-braces, solid wing braces, too-thick bridge plate)

• 4mm soundboard, 4mm back(?)

• Plays and sounds great

Lessons learnt

• double-check before drilling lead jack hole

• always turn away from work when pouring alcohol onto French polishing rubber

• French polish soundboard before attaching bridge

Build #2 - 12-string 12-body-fret 24" scale Parlour

• 2021-22

• over-braced (25mm A-braces, solid wing braces, thinner bridge plate

• 3.5mm soundboard, 4mm back

Lessons learnt

• Don't pipeline multiple guitar builds this early, lest learning the same lesson three times

• Go thinner on those soundboards

• Go more aggressive shaping necks

• Think carefully about bridge placement (scale length / body fret choices)

Build #3 - 25.5" scale GP

• 2021-22

• slightly over-braced (22mm A-braces, solid wing braces, thinner bridge plate)

• 3.5mm soundboard, 4mm back

Lessons learnt

• Don't pipeline multiple guitar builds this early, lest learning the same lesson three times

• Find a way to French polish soundboard before attaching freboard

Build #4 - fretted bass

• 2022

• bracing about right...

• 3.2mm? soundboard, 4mm back

Lessons learnt

• Don't pipeline multiple guitar builds this early, lest learning the same lesson three times

• Be more careful about neck angle, and if not, level frets before setup

• Protect soundboard before installing (and snipping, and filing) rets

Build #5 - 24.5" 14-fret Parlour

• 2022

• Neck milled to 17mm

• 3.0mm soundboard, 3.5mm back

• much less over-braced

• No grain filler on soundboard, experimented with Feast Watson sanding sealer on rest of guitar

• Slightly asymmetric bridge due to carelessness drilling pin holes