ArchtopGuitarKits.com
16-Inch Archtop Guitar Kit
Building Manual
MK16EN_V102.0 1
This Page Inten5onally Le& Blank
2
Introduction Thank you for the confidence that you have put in my products! This is a kit for building a 16” hollow archtop guitar. It looks quite tradi/onal, but there are some details that make it unusual and some among them make it easier to build than conven/onal archtop guitars: The neck uses a tenon-mor/se instead of a dovetail. Thus, it does not have a separate extension as most archtop guitars have. The tenon itself is unusual too: unlike most joints of its kind (perhaps all), this one does not need fi1ng at its le side. The inner surface of the top has been simplified right below the braces. That allows me to supply carved braces that fit perfectly without having to spend a lot of /me working on their underside. The tailpiece is a0ached to the tail block through a bolt that locks into a metal piece embedded in the tailpiece. This eliminates the need for a tailpiece bracket. The volume poten/ometer is disguised under the fingerboard. This is made easier using a special ebony piece that is glued to the fingerboard and to which the pot, in turn, is glued The fret ends are not visible, as the fretboard has two binding strips made from the same material as the fretboard itself. The pickup ring is ebony; it fits the top perfectly and at the right angle. This is something hard to find even in top-class instruments. Most parts are made using CNC technology. All the wooden pieces except the kerfed linings have been manufactured in my workshop in Spain. Metal parts and electronic components are all top quality, some being imported manufactured products. Please note that this kit may be slightly different from what is explained in these instruc/ons. Also no/ce that this is not a complete kit; below, you’ll find a list of addi/onal materials that you will need for its comple/on. Although the materials in this kit are all high quality, we cannot guarantee that the resul/ng instrument is, as skill levels vary. If you have already worked with wood and take your /me following these instruc/ons precisely, you’ll end up with a quality instrument that you’ll be proud of. Good luck!
3
4
Introduction
Check the contents of the box now. They should be as follows: 1 2 3 4 5
An arched carved top made of Spruce, Maple or some other wood. Precut braces, Spruce (2) A carved back made of Maple or some other hard wood A set of prebent sides (2) A shaped neck block made of Sapele or Khaya, which includes a mor5se for the neck 6 A shaped tail block made of the same wood as the neck block 7 Enough length of kerfed linings (around 110” or 2800 mm), made of the same wood as the neck block 8 Enough length of Spruce side reinforcement strips (at least 36” or 900 mm) 9 White plas5c binding strips (2) 10 A semi machined neck, usually made of maple. 11 Peghead face veneer, quite probably made of Ebony 12 An Ebony or Rosewood fretboard, ready to be glued to the neck and sanded 13 Strips for binding the fretboard, made of the same wood as the fretboard (2) 14 A Stainless Steel compression truss rod, cut to size and threaded 15 A truss rod cover piece, made of maple, the same thickness as the truss rod channel in the neck 16 Fretwire (at least 63” or 1600 mm) 17 A bag with a semi machined bridge, made of Ebony or Rosewood, composed of a foot with its base adapted to the top and a compensated saddle. The bag also includes the posts/thumbwheels and an auxiliary nut 18 A semi machined Ebony or Rosewood tailpiece, with an insert for attaching it to the body 19 A semi machined Ebony or Rosewood pickup ring, with its base adapted to the curvature of the top 20 An Ebony or Rosewood finger rest 21 An Ebony or Rosewood truss rod nut cover 22 An Ebony or Rosewood neck cap blank 23 A mold template 24 Peghead sides waste material (2) 25 A CDROM with this manual (high defini5on version) 26 Truss rod adjustment nut, barrel nut and washer 27 PTFE tape, for the truss rod 28 Screws for truss rod nut cover (2) 29 Plas5c rod for side dots 30 Pickup ring screws (4) 31 Tailpiece bolt 32 Finger rest a6achment screws (2)
Introduction
33 Finger rest spacer 34 Finger rest reinforcement strip 35 Blank bone nut 36 Strap holders with screws and felt spacers (2) 37 Maple veneer for shims 38 Magnets (8) 39 Cups for magnets (4) 40 Mold dowel pins (8) 41 Mold tail reinforcing cap 42 Long bolt (M8), with nuts and washers 43 Miniature Poten5ometer for gluing under the fingerboard 44 Adhesive Felt for Poten5ometer 45 Jack, wiring and connectors (3) 46 Jack reinforcing plate 47 Wiring guides (2) 48 Nylon 5e Cannot iden5fy those parts...? You'll find photos at www.archtopguitarkits.com/Kits/Parts16_EN.html
This kit does not contain the following: Pickup: Most conven5onal humbuckers fit the ring supplied with the kit and the hole in the top Machine heads Strings Glue and finishing supplies Case
You will find these parts in most lutherie suppliers; there is a very complete list at h6p://buildyourguitar.com/resources/suppliers.htm If you find some error in the content of the package, or if you need some spares, please contact me at
[email protected]. Ques5ons...? www.archtopguitarkits.com/Kits/FAQ16_EN.html
5
6
Introduction
Before You Start …
Control the rela5ve humidity at your workplace, which must be between 40 and 50%.
Don’t do anything without having read carefully the instruc5ons in advance. Try to complement it with the sec5ons in the books that are referenced at the end of this manual. Previous experience with flat top or even solid guitar kits is great. Keep your edge tools well sharpened.
Some power tools are very dangerous if used improperly, but the same can be said of many manual tools. Read, understand and follow all the safety advices included with both.
Be careful with adhesives and other chemicals. Read, understand and follow the indica5ons in the product MSDS (Material Safety Data Sheet).
Wood dust can be a health and fire hazard. Always wear a mask, especially when sanding wood, and use extrac5on equipment.
This kit includes some powerful magnets that can be dangerous in many different ways. Read, understand and follow the magnet handling safety advices at the end of this manual.
This manual includes metric and inch measurements. I have followed the simple default criterion that, when a measurement is men5oned, I use the intended value (what I was aiming at) first, whatever its units. If necessary, the transla5on to the other system follows, but no5ce that in most cases it is an approxima5on. Feel confident to use any of the two, as the transla5on error has been chosen to be below other sources of error.
Step 1: Building a Body Mold
Molds are used extensively by guitar makers everywhere. They are used to effec5vely support the sides in the right posi5on during the first stages of the building process. When I decided to make this kit, my first worry was how to avoid the maker the pain of making a mold. A&er giving it a lot of thought, I didn’t find how an inexperienced maker could build a guitar like this without using one. Experienced makers could do it somehow, spot bending the difficult to bend curly woods and working with a lot of care, but even they avoid what some call “free building”. Yes, now you know: you will have to make a mold. However, it has some details that make it quite simple and easy to make, without compromising its func5onality or toughness. I have tried my best to make it one of the best molds that you can find, with details such as the magnets that will surely be adopted by other makers in the future. And, last but not least, its construc5on may be as much fun as the construc5on of the guitar itself.
7
8
Step 1 - Building a Body Mold
Tools and Supplies You will need at least two power tools: a Router with a Pa6ern Bit and a Jig Saw. The Pa6ern Bit has a bearing above the cu6ers, so that it can follow a template, effec5vely copying it. If the cu7ng length is not enough for the material that you are using, then you will have to work in two or more passes but, apart from that, almost any commercial pa6ern bit will do. I recommend that, if possible, you use a Drill Press instead of Portable and Manual Drills, but you will need these also. I have used the following manual tools: Cabinet Scraper Chisels (miniature 2 mm and 12 mm) Clamps (at least 15) Engineer’s Square Pain5ng Brush Pencil, Marker Straight Edge Saw
And the following supplies: Mold Template, #23 Magnets, #38 Cups for Magnets, #39 Mold Dowel Pins, #40 Tail Reinforcing Cap, #41 Long M8 Bolt, #42 Epoxy Glue Polyurethane Varnish Wood Glue Waxed Paper Sandpaper (P120)
Step 1 - Building a Body Mold
Procedure The thickness of this guitar at the sides is around 66-68 mm. Without the top and back glued, the sides and blocks (neck, tail) will be around 10 mm less due to them having a thickness of around 5 mm each. Thus, the sides will be 56-58 mm tall. The mold must be thinner than that, so that it can be used to glue the back (and even the top, as we will see) to the sides while these are placed inside it. However, it must not be too thin, as it wouldn’t support very well the sides and it wouldn’t work well for clamping the blocks while they are being glued to the sides. With all this in mind, we will make the mold around 50 mm thick. Fortunately, there are standard thickness of MDF (Medium Density Fiberboard) stock that coincide more or less in most countries, and permit to arrive there easily: use one ¾” (or 19 mm) and two 5/8” (or 16 mm) MDF lamina5ons. If you don’t find those thicknesses, you can use some other combina5on, even using the template itself, but the following instruc5ons describe three-layered molds. Everything will be fine if the total thickness is somewhere between 50 and 54 mm. Standard MDF stock is a material that swells a lot when we6ed. If you use it, you will have to protect it somehow. I suggest that you use polyurethane varnish, as described later. You can use moisture resistant MDF instead, but it is not as readily available as standard MDF. Before you start making the mold I would like to men5on that there exist the open and closed varie5es. Open molds are formed by two halves that are a6ached by toggle latches or a similar mechanism, and allow easy removal of complete glued soundboxes (top, back and sides), if this construc5on method was used. Closed molds cannot be disassembled and are used to glue the back (or top) to the sides, but closing the soundbox using the mold is not recommended, as there is no guarantee that the guitar can be extracted without suffering damage. The mold described here is a third kind, midway between both types. It can be opened at the tail, but not at the neck end.
9
10
Step 1 - Building a Body Mold
Separate the two parts of the template cu7ng the tabs and smoothing them with a chisel and sandpaper. Work with the outside part, which is the real template; the inside will be used later. A6ach the template to one of the thin (5/8” or 16 mm) MDF boards, using a few clamps. Drill the six holes in the stock as in the template using a 5/16” (or 8 mm) pilot point drill bit; try to keep it perfectly upright (use a drill press if possible). Using the dowel pins instead of the clamps, trace the outline of the template on the board.
Remove the clamps and cut it with the jig saw, following the pencil lines, inside and outside, and leaving a li6le to be trimmed by the router later.
Do the same for the other two boards. Eventually you will have the three lamina5ons and the template. Don’t discard the three central sec5ons.
Step 1 - Building a Body Mold
I will show you several ways of rou5ng those lamina5ons to get an
accurate shape. For the first method (first and second pictures), join the three lamina5ons, using the 8 mm dowels supplied with the kit and, on top, the supplied template. Don’t use glue yet. Now use the router with the pa6ern bit to copy the template to the mold lamina5on above.
I have used clamps and a heavy chunk of wood to fix the lamina5ons to the table. The idea here is to use the template first and then remove it, using each routed lamina5on as a template for the one below it. This is a simple method, but you will have difficul5es trying to keep the router straight, because the narrow mold walls are not a steady base for it.
The second method fixes that problem with the stability of the router. It involves the use of a rou5ng table where the router is placed upside down, in this case with a Flush Trim Bit instead of a Pa6ern Bit. I consider that a rou5ng table is not difficult to make; you may even find commercial units that can be adapted to a great variety of routers. If you plan to rout a binding channel for your guitar with a minimum guarantee of success, a rou5ng table is the easiest way to go. By the way, I was only posing for the photo. Otherwise, my hands would be farther away from the bit! Rou5ng tables are not available to everybody, so there is another alterna5ve: use the central part of the template. Screw it to one or more of the central pieces that you sawed from the boards and you will have a wider base for rou5ng the outside curve.
11
12
Step 1 - Building a Body Mold
Rou5ng the inside will not be possible unless you make the central base smaller, leaving enough room for the router bit.
Whatever the method, you may cut more than one lamina5on if the bit length permits it; if not, you may need to remove the template and use the area that has been cut on the lamina5on above as the new template, placing and removing lamina5ons similarly for the central support if you use it. This is only a guide, and what you do depends a lot on the bit dimensions and other factors.
Step 1 - Building a Body Mold
Now that you have cut the three lamina5ons, get the middle lamina5on and, using a chisel, cut four recesses at the points shown.
These must allow the placement of the magnets supplied with the kit. Their external surface must be as close as possible to the inner surface of the mold, but not protrude above it. Warning: these magnets are excep/onally strong and can be dangerous if your skin is caught between them. Wear gloves and work with one magnet at a /me, keeping the others at a safe distance. Read the important safety rules at the end of this manual!
13
14
Step 1 - Building a Body Mold
Magnets…?? The waist spreader in most molds is based on a turnbuckle screw that pushes upon the waist. While it is not difficult to make, you will need to cut two addi5onal blocks that act as intermediary between the screw and the waist. There are other designs; the one shown here, used by some makers, is elegant and simple. However, neither of these designs will allow you to close the soundbox with the waist spreader inside, at least in guitars with limited access (f-holes instead of round hole, for example). I considered that a necessity for a guitar built by someone who cannot retouch the sides in a bending iron. These magnets may not be as powerful as turnbuckle screws, but wait 5ll you see them in ac5on!
Now glue the three lamina5ons together; use wood glue (I used Titebond), spread it well with a brush, use the dowel pins to keep the three lamina5ons aligned except the pin at the tail end and, finally, clamp everything. Be careful when gluing the lamina5ons, as they may slip, losing their alignment. To avoid that, do it in two or three steps, using gradually more clamping force. Try not to use a lot of glue to avoid ooze-out, especially around the recesses for the magnets. If you look at the photo you’ll see a lot of clamps; you can do this with less, but my recommenda5on is that you have at least 15 – you’ll need them later.
Step 1 - Building a Body Mold
When the glue is dry, remove the clamps and check the ver5cality of the inner walls. This is very important at the neckblok area! Correct them with a cabinet scraper, also removing the dried glue from inside and outside.
Use a saw and a small chisel to shape the area at which the router bit couldn’t arrive, opening a small recess for the cutaway side.
15
16
Step 1 - Building a Body Mold
Trim the excess off the dowel pins.
Glue the supplied tail reinforcing cap.
Trim it and then apply two or three coats of polyurethane varnish to protect the mold from water spills, as MDF swells a lot when we6ed. Try to avoid varnishing inside the cavi5es for the magnets. If you’re using moisture resistant MDF, you may skip this step.
Step 1 - Building a Body Mold
We will install the magnets now. There are eight, separated by plas5c pieces. They are magne5zed so that it’s their faces that are North and South. While they are all in a row, write their polarity with a permanent marker (there's a 50% probability that you get it wrong, but it doesn't ma6er)..
All the magnets in the mold must show the same polarity outside, N for example. Get four magnets and, working one by one, sand their S surfaces (P120) un5l they are rough. Use a good epoxy to glue them in the mold cavi5es, S face down. Use a plas5c straight edge to verify that they are flush with the inner surface of the mold.
Work now on the remaining four magnets. Again, work one by one, sanding the N faces this 5me. Epoxy them to the four supplied cups, N face down. With these precau5ons, the fragile magnets may s5ll collide, but there will always be a wooden cup between them.
17
18
Step 1 - Building a Body Mold
Drill a 5/16” (8 mm) hole at the tail end for the M8 bolt (#42). Be careful to make it straight, especially if you need to drill from both sides.
Trace the center line at the neck end. Use the hole for the dowel pin as a reference, as it is located at the center line of the instrument. Mark it permanently making shallow cuts with a fine saw.
Step 1 - Building a Body Mold
Similarly, draw the center line at the tail end, but this 5me cut the mold along it.
Now the mold can be opened at the tail end. It is 5me to glue the last 5/16” (8 mm) dowel pin in its hole. Apply glue to a half of it only, so that it is glued to one of the sides of the mold. Avoid contact with the other side using a piece of waxed paper or similar.
With the dowel pin glued, you’ll no5ce that both halves don’t close completely. There is a narrow gap le& by the saw, which you must close now. Glue the correct thickness of cardboard or wood to one of the sides, again using waxed paper to avoid it gluing to the other side.
A&er the glue is dry, trim the glued pieces and retouch with polyurethane varnish. Finally, install the M8 long bolt with its washers to close the mold.
19
20
Step 1 - Building a Body Mold
Now that you have finished the mold, put the sides in it, using a few spring clamps and the magnets. If your clamps do not have so& jaws, use small wood pieces in between. You can leave the sides in the mold for a long 5me, but they should stay clamped to avoid distor5ons. No5ce that, as the tail area is not trimmed yet, it cannot be clamped adequately: I recommend you to follow the order of opera5ons in this manual and start working on the sides now. USING THE MOLD TO FINE-BEND THE SIDES If you find that the sides don't fit well inside the mold, leaving more than 1/8" at some places, wet them well inside and out. Clamp them to the mold using as many spring clamps and wood intermediaries as you need to get a good fit without distor5ons or cupping. The wet wood is very so& and can get impressions quite easily, so try to use some so& material between the intermediaries and the sides. Once dry (typically one day), work on them soon or you'll have to repeat the procedure again. Wet sides can damage the mold, and that's the reason why it must be varnished. But the mold can cause damage to the sides too, the main reason being the magnets having lost their chrome pla5ng due to collisions with other magnets. The oxide in the magnet will contaminate the sides and you will get a nasty black spot. If you see that the surface of the magnets is chipped, cover them with tape whenever you place wet sides in the mold.
Step 2: Preparing the Sides
The sides, as supplied, are already bent. It is not easy for a supplier to do that, because bending curly woods is far from being a simple procedure, especially at the cutaway area. In fact, it can get so frustra5ng that I am sure that this is one of the aspects that any archtop guitar maker with previous experience will value most for this kit.
21
22
Step 2 - Preparing the Sides
Tools and Supplies Prepare to collect as many Miniature Spring Clamps as you can, for gluing the kerfed linings to the sides. Some makers use clothes pins instead, but most 5mes the spring is not enough for the job. Some others use modified clothes pins (usually with a rubber band wrapped around them) that seem to work fine. You will need a Drill and some Drill Bits (see details at the Procedure sec5on). Also a Chisel, Saw, Pencil, some Spring Clamps and a good quality Machinist Square. There are other more special tools that you'll probably need, described in the Procedure sec5on. You will need the following supplies: Sides, #4 Neckblock, #5 Tailblock, #6 Kerfed linings, #7 Spruce side reinforcement strips, #8 Wax paper Sandpaper (P80, P120, P180 and P220)
Step 2 - Preparing the Sides
Procedure The first thing that you will need to do is find a good flat working table. Place the sides inside the mold, flat on the table, and clamp them using the magnets and some spring clamps.
Watch the gap between them at the neck area. Contrary to the tail block, this doesn't need to be very narrow, but you can trim it anyway following the procedure shown in the pictures, using a machinist square and a block plane. You'll avoid tearing out the wood (end grain is frail) if you start from both ends.
Note: A&er making the guitar for this kit I discovered that the neck heel was not tall enough to cover the en5re joint between the sides at the neckblock, unless a very thick heel cap was used. If you look at the neck in your kit, it has a taller heel to avoid this problem. Addi5onally, I don't want to give you a heel cap that is much thicker than what is necessary, so, if you don't plan to bind the back, don't make a lap joint as shown at right, because the neck cap won't cover the end grain of the cutaway side completely. For unbound backs, use a miter joint. [See also page 94]
The block plane is not included in the list of tools; you may use files, sandpaper, etc.
23
24
Step 2 - Preparing the Sides
The neckblock can be glued without much prepara5on using Titebond. You will need to sand or scrape the gluing surface at the sides, with the purpose of cleaning the quite possibly dirty maple. Do a dry run first! The blocks and the sides are both made from stock 58 mm high. However, we7ng and hea5ng the wood for bending may modify its dimensions. Addi5onally, there will be some tolerances that you'll surely find a&er you glue the blocks. This is why the final thickness of the guitar at the sides may range between 56 and 58 mm.
Use a few clamps to press the neckblock while gluing, keeping everything flat.
While the glue sets, you can find the points at both sides where they will meet at the tail end. Use spring clamps to adapt one of the sides to the mold without leaving gaps, and then mark the center point. Do the same for the other side.
Draw a line at the marks found, using a machinist square. Cut the excess with a saw and refine it with a block plane (if not available, use a file or sandpaper).
Step 2 - Preparing the Sides
With the mold and sides firmly on the table, check that the joint is at the center of the instrument and that the gap is not wider at one of its ends, correc5ng the joint with the block plane if necessary. With the basic joint already done, you'll have to refine it in order to make the gap as small as possible. Use sandpaper, a small hard sanding block and a lamp behind the joint: you must not see any light through it.
When sa5sfied, join the sides with tape. Note: For some tapes, when the tailblock is glued to the sides the pressure put by the clamps will cement the tape to the sides very strongly. You may damage the sides if you try to remove the tape without using alcohol or acetone!
Put them inside the mold using some wax paper in between. Sand the gluing surface because, as before, the sides may be dirty. Find the center of the tailblock and mark it with a pencil. When you glue the block to the sides (using Titebond), keep everything flat on the table and the center marks aligned. Do a dry run first! No/ce that your tailblock may look different from the one shown here. With the new design, you may use addi/onal clamps (arrows):
25
26
Step 2 - Preparing the Sides
A&er sanding the inside of the sides (P120, P180 and P220), you'll install the kerfed linings. There are four lengths of this material in the kit, enough for the en5re guitar and some le&over just in case. Some guitars have uninterrupted linings from neckblock to tailblock. While this saves 5me at the factory, it is not an acceptable method. Without the side reinforcement strips, the sides would probably rip open a&er a moderate blow, ruining them. If the strips are there, but they don't cover all the width of the sides, the danger is s5ll present, so the best solu5on is to interrupt the lining strips with the side reinforcement strips. Begin cu7ng 16 lengths of 17 teeth. The rest will be approximately two lengths of 23 and two more of 20 (see diagram), but this may vary, so wait un5l you have glued all the 17-teeth lengths.
With the supplied kerfed lining, each 17-teeth piece will be around 113 mm. Glue the linings (Titebond), clamping them with the spring clamps. They should be a hair above the sides. As always, remove the glue ooze out.
Step 2 - Preparing the Sides
Insert spruce side reinforcement strips between the lining pieces. You must not glue them yet.
When you glue the lining at the other side, use the strip as an alignment. As before, don't glue the reinforcement strips yet. At areas with high curvature, (waist and cutaway), you will have to saw the kerfings almost all the way down before gluing. Otherwise, they will break.
Take each reinforcement strip and shape it as shown. If you use sandpaper alone it will be easier.
27
28
Step 2 - Preparing the Sides
Glue and clamp each strip (use Titebond). Do it with the sides in the mold, so that the spring clamps exert enough pressure to adapt the flat strips to the curved sides.
Glue a couple of teeth to each strip at each side.
This came as a surprise. I hadn't used magnets in molds before, and I didn't contemplate the possibility of the magnet being right below one of the reinforcement strips. However, it has power to spare, and will work well even in that situa5on.
You must make a tool for sanding the excess height at the linings and blocks. It is a long piece of wood with sanding paper (P60 or P80), glued (I use double-sided tape) at one of its ends, as shown. You can improve it easily using hook-and-loop fastening.
Step 2 - Preparing the Sides
If you trace a line along the sides, you will know when to stop sanding.
It is not necessary that you use clamps, just the magnets. When you are sanding at a certain area, press the side against the mold with your free hand; that will be enough.
The blocks must be sanded carefully. If you don't do it right, you won't get a flat gluing surface for the top and back. Also, you may disturb the angle between that gluing surface and the sides, that must be a right angle. If that happens, you will probably have to make tedious correc5ons to the neck angle when you glue the neck. To avoid that, press the neckblock and tailblock to the sides using a clamp. This is be6er and simpler than using a turnbuckle screw from block to block. In ideal condi5ons, all the sanding will be limited to the blocks and linings. However, it is possible that you have to sand the sides, making them narrower, due to small construc5on errors (typically, small imperfec5ons in the mold or in the gluing of the blocks). This is not a big problem for later stages, at least if it is not much more than, say, 2 mm. If it happens, try to keep the sides the same width everywhere.
29
30
Step 2 - Preparing the Sides
A&er some detail sanding, this is the way the sides look inside the mold right before gluing the top and back:
Step 3: Preparing the Top
Tops are usually made of so&wood. This makes carving them quite easy, especially when comparing the curly maple used for the backs. However, they are trickier to make: they have pickup and fholes, braces and more complex thickness gradua5ons. I have tried to simplify these tasks: the holes are open and the braces are extremely easy to fit. The braces deserve some more comments. The first version of this kit had "integral" braces (carved in the top). As the strength of a brace is highest when the grain runs straight along it, they were perfectly parallel. However, most makers think that braces must form an angle with the direc5on of the grain at the top; otherwise, there is an increased danger of spli7ng the top along their corners. Unfortunately, this rules out the integral braces. What I have done is to simplify the inner surface of the top right below the braces, making it the same height at both sides of the brace. That way, I can make them using a template, and they will fit perfectly without any further adjustment. Despite these simplifica5ons, you'll s5ll have to graduate the top, but most of it will be done a&er the soundbox is closed (see Step 7, Binding and Tuning the Soundbox).
31
32
Step 3 - Preparing the Top
Tools and Supplies The top and back, as supplied, don't need much addi5onal carving. A cabinet scraper with a curved shape is a great tool when you don’t have a lot of wood to remove (removing the machining marks, carving the recurve...). While the “French curve” scraper (first picture, le&) may have some other uses, you may also use a rectangular scraper with one or more corners ground, as the one to the right. You will need gouges and chisels. These are great carving tools that can reach inside corners, for example around the gluing areas for the neck and tail blocks. Chisels are also great for trimming the braces to their final shape. You’ll need clamps for gluing the braces. Steel clamps of the required throat depth are usually very heavy; it is preferable to use the lighter wooden cam clamps. You’ll have to sand also, manually or with an electric sander. Finally, you will need some other common tools such as a pencil and a measuring ruler. If you have built more archtop guitars, perhaps you have learnt to es5mate the plate thickness with enough precision simply using your hands. You can exercise this ability by having some wood pieces of known thicknesses at hand. The tools described below will definitely make your work easier, but they are not necessary.
The best tool for carving tops and backs is a plane with its sole curved (le&).
Step 3 - Preparing the Top
These are mainly sold for violin builders, and are available from many lutherie suppliers. You will find them in many sizes, but the larger planes (palm planes, le& in the picture) are unnecessary because both top and back have been rough carved already. I prefer to use a smaller finger plane (the one to the right in the picture) with a blade width of 12 mm.
As an alterna5ve to the method described, you may use a thickness caliper for measuring the thickness of tops and backs (right). You will need the following supplies:
Top, #1 Precut braces, two pieces, #2 Side reinforcement strip material (for the pickup hole), #8 Glue (Titebond) Sandpaper (P80,P120,P180 andP220)
33
34
Step 3 - Preparing the Top
Procedure Before doing anything, take your 5me studying the top. No5ce the following:
The machine carving has been done with a square bit. This means that you will no5ce some “stair stepping” especially where the slope of the surface is higher. The top has been cut approximately 1/8” (3 mm) bigger than necessary, all around. As supplied, the top has three different regions. The central region has a uniform thickness of around 6.5 mm (¼”). The other two are around 5 mm (3/16”). There are two smoother regions at both sides of the central region, about 8 mm (5/16") wide, clearly visible in the picture. Those are the surfaces where the braces must be glued. The size and outline of the f-holes is quite tradi5onal. You may enlarge them either to change the overall shape or to make more room if you want to install bindings. These holes follow the tradi5onal rule that locates the bridge approximately between their inner 5ps. When we men5on the bridge area (and we’ll do it a few 5mes), you will be able to locate it easily if you remember this rule. There is a par5ally finished aperture for the neck tenon. It is undersized: 1.5 mm (around 1/16”) smaller than it should be, all around. You can compare its size now with the size of the cavity in the neckblock, which has the right final dimension.
The inside of the top has been machined using an upcut bit. This means that the edge of all the ver5cal surfaces will surely need a li6le cleaning of the dangling fibers. Use a piece of sandpaper (P120) everywhere that you see them; forget the areas that show a lot of stair stepping, as they will be smoothed soon using other methods. Be careful not to remove more than necessary, and don't sand on the surfaces where the braces will be glued. For all that follows, it is advisable to trace the outline of the guitar at the top plate, inside. This can be done easily measuring 441 mm (17 23/64”) from the end of the aperture for the neck tenon:
Step 3 - Preparing the Top
This distance will be measured with the top as supplied, i.e., with the undersized aperture for the tenon. Once the end point of the guitar at the tail has been found, all that remains is to use the mold to trace the outline. Fine tuning the top has to do with giving it enough structural s5ffness and a long life free from deforma5ons, while at the same 5me giving good tone and volume. If you choose not to modify the gradua5ons that will be great for electric instruments, but you will definitely get a be6er acous5c tone (and even its electric counterpart) if you modify some of them. In par5cular, the area right behind the bridge is thicker than necessary. I could have made it thinner but then, if you decided to start an X-bracing design of your own, that area would probably be weak. Removing the wood from that area is easy with a chisel, as shown.
35
36
Step 3 - Preparing the Top
If available, use a finger plane.
Very important: for all the opera/ons that follow, don't remove any wood from the smooth areas to the sides of the central region, where the braces will be glued later. You will need to carve quite close to them now; I recommend that you mark with a cu6er first and then cut with the chisel, as shown.
When you work at the tail end, don't carve beyond the last CNC machining mark.
Step 3 - Preparing the Top
The final gradua5ons in this area will be as shown here:
There is an area of 5 mm or a li6le more (“5+” in the picture), then a transi5on area and finally an area of around 6.5 mm. These are inner gradua5ons; the final tuning will be done later, when the soundbox is closed.
Remove the stair stepping from everywhere inside the top. Here I am doing it with a finger plane, but you may use many other things, electric sanders being a valid alterna5ve if you are good at controlling them.
37
38
Step 3 - Preparing the Top
Don’t remove more wood than necessary. Also, it is very important that you work at a safe distance from the edge of the instrument to avoid modifying the flat area that will be glued to the sides.
Again, use gouges and chisels for reaching near the base of the braces (be careful) and around the neck block gluing area.
If you are new to carving wood, you will discover that grain direc5on may guide the tool if the shavings are too thick, or if your tools are dull. Tear-out as shown at le& can be avoided simply by changing the carving angle or by adjus5ng the tool for a thinner shaving. I suppose that your tool is sharp as a razor – is it?
Step 3 - Preparing the Top
No5ce that we haven’t thinned the top ahead of the bridge. I have found that this raises a li6le the feedback threshold but, if you don’t care, thin the area similarly to what you have done behind the bridge. If you do this, you should leave a round area below the bridge, extending about 50 mm (2”) to both ends, where the top must be around 6.5 mm thick. Don’t be afraid for the edge of the pickup hole being too fragile at 5 mm (or less a&er thinning the outside): we will glue a small transverse brace there.
Next we will glue the braces. As men5oned, they are ready for gluing. The brace to the right (corresponding to the non-cutaway side) is marked "2". The other brace (cutaway side) is shorter and it is marked "1".
Check that there are no gaps at any point along the en5re length of the brace. Where there are faint machining marks, remove them very carefully, using sandpaper or, preferably, a razor blade. Glue them, one at a 5me. As always, clean the ooze out.
I have used four small and four large cam clamps. It can be done with less, however. The braces tend to slip out of place when clamped. To avoid this, press them in place by hand before clamping, and don’t apply full clamping pressure at first. Use whatever clamps you have available, but try not to use heavy clamps that may harm or even break the top.
39
40
Step 3 - Preparing the Top
A&er the glue has dried, begin removing wood from the top of the braces with a chisel. The central area of the top must be s5ff from neck to tail. You can check it by pu7ng pressure with your thumbs, using the mold as a support. You will feel that the bridge area deforms more under the same pressure, the main reason being that it is at the center of the top. Carve the braces so thatyou can feel more or less the same s5ffness at the bridge and near the end of the braces at the tail area, where I am pressing in the picture. That means that the tail end of the braces will have to be thinner. How much thinner is a subjec5ve ques5on, but this picture will let you judge how the braces should look a&er this ini5al carving:
The highest point is at the bridge area, where their tops should be at a height of around 18 mm (11/16") above the surface of the top.
Step 3 - Preparing the Top
Beam theory shows that the deflec5on of a beam of rectangular sec5on is inversely propor5onal to its width and to the cube of its thickness. Thus thick (tall) braces are great at suppor5ng the pressure from the bridge with li6le weight. Our braces are tall already, so we will shape them removing material from their tops, giving them a somewhat parabolic sec5on:
You may want to remove some more wood making the braces lower. That's correct; in fact, if you have followed my recommneda5ons you must have an ample safety margin. Sand the braces and the rest of the top (P80, P120, P180 and P220). If you use an electric sander, like I'm doing here, be careful with the f-holes. Almost all sanders are too big for the central sec5on between the braces, so you'll have to hand sand there. Glue a piece of the same material that you used for the side reinforcement strips (spruce) to reinforce the pickup end grain. It must go between the braces:
41
42
Step 3 - Preparing the Top
If you have used an electric sander, sand the top manually (P220) following the direc5on of the grain. Electric sanders usually leave very small spiral marks, but even if they are invisible inside the closed soundbox, a smooth surface is great at avoiding the dust s/cking to it. There is a situa5on when sanding marks inside the soundbox may become visible, and it is a&er you seal it with shellac (we won't do this). Some makers favor this prac5ce because it slows the exchange of humidity with the environment.
Note that the contour line has disappeared in many places a&er sanding. You may trace it again, but only if you know posi/vely that you are going to install binding at the top/sides joint. Otherwise, be extremely cau5ous with the pencil: when you glue the top to the sides, it will make the joint much more visible.
Step 4: Preparing the Back
The techniques and tools that you have used for the top will also work for the back. Being quite close to the final gradua5ons, it will not be difficult to carve it in spite of curly maple being so temperamental.
43
44
Step 4 - Preparing the Back
The back (#3) should be carved to a uniform thickness of around 5 mm (3/16”). Currently, it is around 6.5 mm (1/4"). Being hard wood, not braced, not having to stand a lot of stress and being very important for shaping the tone of archtops, we'll carve it more flexible. You'll have to remove wood from all areas, but be careful with the gluing surfaces for the sides/blocks. Thus, the first thing to do will be to protect those areas from your tools. To trace the outline of the guitar on the back, take the line where its two halves join as the reference. For the sides, their mid point at the tail end is evident, but at the neck end you'll have to measure 27.5 mm (1.08") from the wall of the cutaway:
(Note: You can use the mid line at the mold instead)
The first photo shows how to mark the sides with that measurement, using a machinist square. With all those references, and using the sides already assembled inside the mold, trace the outline of the tailblock and neckblock, as in the second photo. Never carve beyond the lines or too close to the edge of the instrument (third photo). Curly maple is much easier to work if your tool goes across the grain. In case of trouble, change direc5on. Here I am using a finger plane, but you can use gouges instead.
Step 4 - Preparing the Back
Near the tailblock you will have to remove more wood, crea5ng an abrupt transi5on.
Near the neck end, round the corner of the ver5cal wall at the neckblock transi5on.
Work with a gouge at the abrupt transi5ons near the neckblock.
45
46
Step 4 - Preparing the Back
This is the aspect of the area near the neckblock a&er carving it.
Here you can see the carved back, right before sanding. Its thickness is more or less constant, around 5mm (3/16") everywhere. The flame is more evident now.
Sand the back, using P80 or rougher and then going up to 220. You may use an electric sander, but the last step should be done manually, following the direc5on of the grain. Electric sanders usually leave very small spiral marks, but even if they are invisible inside the closed soundbox, a smooth surface is great at avoiding the dust s/cking to it. There is a situa5on when sanding marks inside the soundbox may become visible, and it is a&er you seal it with shellac (we won't do this). Some makers favor this prac5ce because it slows the exchange of humidity with the environment.
Step 4 - Preparing the Back
This is the back a&er the final sanding:
The flame is less evident now, but it will jump again a&er the finish is applied. Note that the contour line has disappeared in many places a&er sanding. You may trace it again, but only if you know posi/vely that you are going to install binding at the back/sides joint. Otherwise, be extremely cau5ous with the pencil: when you glue the back to the sides, it will make the joint much more visible.
47
This Page Inten5onally Le& Blank
48
Step 5: Preparing the Neck
Probably this is the part that will take more 5me and effort from you. Necks have a lot of parts, and must be built under very low tolerances. Despite the many steps, you will not face difficult problems if, as always, you don't rush things and read everything very well before grasping a tool.
49
50
Step 5 - Preparing the Neck
Tools and Supplies A Cabinet Scraper is the best tool for removing the carving marks le& by the CNC machine. You will need Chisels, Gouges, some conven5onal Clamps and a few Spring Clamps. A Coping Saw and Files are the tools recommended for cu7ng what remains of the shape of the peghead. You will need some small Drill Bits (read the Procedure sec5on for details) to use with a Hand Drill. A Center Punch made of hardened steel is the best tool for a6aching the barrel nut to the truss rod. Adhesive Tape works fine for holding the bindings in place while the glue dries. You may use strong tape (filament tape, for example), especially if you are going to need it also for gluing the body bindings. However, I will explain here the method that works better for the wooden neck bindings, for which you will need a few meters of Cord. Cleaning the slots a&er the neck bindings are glued is a must. You may use a Fret Slot Cleaning Tool, available from some lutherie suppliers or make your own. Some opera5ons (for example, fre7ng) will require addi5onal tools – please read the Procedure sec5on below. You will need the following supplies: Neck, #10 Headplate, #11 Fretboard, #12 Ebony binding strips, #13 Truss rod, complete, #14 and #26 Truss rod cover, #15 Plas5c rod for side dots, #29 Nut blank, #35 Fretwire, #16 Peghead sides waste, #24 PTFE tape, #27 Wood glue (Titebond, regular and for dark wood) Toothpicks
Step 5 - Preparing the Neck
Cord, 8 meters/yards Sandpaper (P80, P120, P180, P220, P360, P600, P800, P1200)
51
52
Step 5 - Preparing the Neck
Procedure Before doing anything, take your 5me studying the neck. It is made of three main lamina5ons, that become five at the peghead. As other parts that you have seen before, it shows stair stepping. The picture also shows that the CNC machine didn't finish the peghead transi5on completely.
The top of the peghead, where the maker usually writes his name, has not been cut. This is because the design of the peghead is usually one of the signatures of the maker. There are many designs for which the holes are not where I have drilled them, but I decided to drill them anyway, as it is a process that can go wrong quite easily. No5ce the channel for the truss rod. Its bo6om is semicircular, but it has the same depth everywhere. At the heel end there is a hole for the barrel nut. No5ce also that the area right below the nut has two parallel pencil marks. They represent the two faces of the nut, i.e., the beginning of the peghead and the beginning of the fretboard. The CNC machine could not remove all the wood from the tenon, due to the radius of the cu6er.
Our first task will be to install the truss rod. Measure 1/2” (13 mm) from the beginning of the peghead (the vertex of its angle) to the beginning of the access cavity; draw two lines (the sides of the cavity) at a distance of 7/16” (11 mm). Clamp the peghead, not the neck: with the truss rod channel empty, it can break easily. The kits include the two waste pieces that were cut from the sides of the peghead so that you can use a conven5onal vise, as shown in the picture.
Step 5 - Preparing the Neck
With a narrow chisel and a hammer, cut the ver5cal wall at the beginning of the cavity. Be very careful: it must be normal (perpendicular) to the surface where the fretboard will be glued, not to the peghead.
Use a gouge to open the rest of the cavity. This opera5on and the previous one must be done in several steps, each one deeper.
To check that you have reached the right depth, screw the brass nut to the rod (to the side with a longer threaded sec5on), put it in place and try to turn the nut with the supplied wrench; It must be possible to insert and turn it, but try to remove the minimum amount of wood.
Remove the brass nut and screw the barrel nut to the end of the rod with the shortest length of threads. Check that the access at the other end, brass nut and washer, is correct; when you are sa5sfied, peen the barrel nut to the rod using a hardened steel center punch and a heavy hammer. Do it at both sides of the barrel nut.
53
54
Step 5 - Preparing the Neck
Wrap the rod in PTFE tape and insert it inside the channel. Note: Although the truss rod has 10-32 threads at its ends, it has been made from 5 mm instead of 3/16" (4.8 mm) rod. Anyway, as the width of the channel is a hair above 5 mm, you won't probably find problems inser5ng the rod with the tape in it. If you do, file lightly each side of the rod.
Cut the cover to size, glue it above the rod (Titebond) and press it with three or four clamps. Do the same for that sec5on of the channel that doesn't have a rod below; for this, shape the base of the wood cover with some sandpaper un5l it has a semicircular sec5on (the bo6om of the channel is round) Don't throw away the cover le over. We will use it later.
Step 5 - Preparing the Neck
Once the glue gas dried, use a wide chisel and then a cabinet scraper to remove the truss rod cover excess.
55
56
Step 5 - Preparing the Neck
Center the fretboard and place it above the pencil mark. This is because the finished nut, ini5ally 5 mm thick, will be a li6le thinner in the end due to sanding and polishing. Ideally, the nut should fit perfectly inside its channel; this is one of the places where guitar making needs all your precision, so take your 5me posi5oning the fretboard prior to gluing it. Hold it with strong spring clamps.
Check the alignment once more, and then drill two holes at the first and last fret. They must have a diameter a hair below the diameter of a toothpick (I use a 2 mm bit – not all toothpicks are equal, not even inside the same box, but they use to be a li6le more than that).
Remove the fretboard and insert a length of toothpick inside each hole. The fretboard should align perfectly now with just the two toothpick guides and without the spring clamps.
The main problem to avoid when gluing the fretboard is neck distor5on. As the gluing surface is large, you will have to use a lot of clamps. These are usually heavy, so it is common that the neck is under stress while the glue dries. A part of the problem can be attributed to the water in the glue (Titebond in this case), but that must be a much less important factor. In my experience, the best way to avoid this problem is to let the neck rest on its side while the glue sets, using iden5cal clamps placed to the same side.
Step 5 - Preparing the Neck
Try to 5ghten the clamps progressively, in several passes, as the glue makes everything much more slippery, even with the toothpicks. Clean the glue ooze out. Use a wet piece of cloth and then a chisel. Do it very well while wet and a&er it has dried: the binding must sit on flat and clean surfaces. Check the two ebony binding strips. One of their sides is flat (the narrow sides, the ones that should be glued to the neck, not to the fretboard); the other may or may not be, so beware. They must be taller than the edge of the fretboard, but not much more than 1 mm. Scrape them if necessary. Apply glue to the binding (use preferably Titebond for dark woods, or add two drops of black water dye to some of your regular Titebond) and use a length of cord (8 meters/yards should be more than enough) to clamp the bindings in place, applying a firm constant pressure. Don't use adhesive tape here: the cord is much simpler and it works much be6er.
While the glue is s5ll wet, you can clean some or all the slots with a small tool that you may find at some lutherie suppliers or at some hobby shops, or even make yourself (as I did). If you are careful placing the cord over the frets, you will be able to clean them all.
57
58
Step 5 - Preparing the Neck
A&er the glue is dry, remove the cord and clean the slots again if necessary. Before sanding the fretboard, check its straightness with a straightedge and correct if necessary with a cabinet scraper or sandpaper (P80 or P120). Then sand the en5re fretboard surface un5l you cannot see any router marks. You may use a radiused sanding block (12" curvature radius) or a straight wooden block; avoid using any so backing. Always watch the ends of the fretboard at the first and last frets: it is easy to sand them more than necessary. If that happened, it wouldn't be very no5ceable now, but it surely would show up a&er the fretboard surface was polished.
Sand the sides of the fretboard so that the transi5on between the fretboard and the main body of the neck is smooth. With a pencil, draw a line along it and locate the center of frets 3, 5, 7, 9, 15, 17 and 19. These must be marked with single side dots. Fret #12 must be marked with a double dot.
Step 5 - Preparing the Neck
Drill the holes (hand drill!) at the points marked, using a 1/16” (1.5 mm) bit at a depth of around 3 mm (1/8”).
Use superglue for gluing enough length of the white plas5c rod. A&er the glue sets, file them even with the fretboard surface.
Now you will sand and true the bone for the nut. This is the first step for preparing the gluing of the headplate. The bone is probably rough now, but it will shine if you sand it following the grades: P220, P360, P600, P800, and P1200. Wrap some tape around your fingers to aid holding it against the sandpaper; always try to keep its faces well squared.
Chisel out the ends of the binding strips at the nut.
59
60
Step 5 - Preparing the Neck
Sand one of the face-grain edges of the headplate on a flat table un5l you get the same angle as the peghead. This is important, as you won't make any further adjustments to the nut channel. The two faces of the nut should fully contact the end of the fretboard and the end of the faceplate.
Hold everything with strong spring clamps and drill two holes (2 mm). There will be one near the nut; the loca5on of the other hole depends on your design for the headstock, but you cannot be very wrong if you place it at the upper corner, as shown. Use toothpicks as you did when you glued the fretboard. Note: Most commercial headplates have a width of 3½”. This is not enough for most archtop headstocks, that are a li6le wider, so many makers need to “cut and paste” peghead material. I have enough stock of 4” wide peghead veneers, and that's what I will supply with the kit.
Before gluing the headplate it is advisable to open the access hole for the truss rod nut in it. You can do it a&er it is glued, but the wood may get damaged especially where you have to cut along face grain. I have an easy method for which you will need just a little white paint, that you will apply to the corners of the hole, as shown.
Step 5 - Preparing the Neck
Plug the veneer into the guiding toothpicks and you will have the reference of where to cut.
Drill some holes and then work with files and chisels un5l you get the access right.
Now you can glue the headplate, using Titebond. Use a flat block above it to even up the clamping pressure (some MDF le&over from the mold...?). Don't clamp too strong or you may break the peghead; it is be6er to use many clamps with a moderate pressure at each one. You don't want a lot of glue inside the tuner holes or the truss rod access cavity: use as li6le as possible and, as always, clean the ooze out.
61
62
Step 5 - Preparing the Neck
Now it is 5me to decide your headstock design. It is not easy to find something really new that doesn't look odd. You have an obvious size limita5on, but there are other concerns; for example, if you are going to use the same design in the future, think very well how you will manage to rout the peghead binding channels. Also, study how you will rout the peghead shape using a template; perhaps it will not be possible if there are, for example, 5ght curves. In the end, if you don't want to spend a lot of 5me working on the peghead, you will arrive at some simple designs, most of which have been used already. If that's your decision, I suggest that you try to refine their propor5ons un5l you make them more personal. For this guitar, I have chosen a very simple design; if you want to use it as it is or modify it somehow, you may download it here: www.archtopguitarkits.com/Kits/Peghead_16i.jpg
The real dimensions of the rectangle that encloses the drawing are 140x230 mm. We'll cut the peghead shape with a coping saw and then refine it with files and sandpaper. If you print the peghead shape, cut it and then glue it to the back of the peghead, it will be easier.
Step 5 - Preparing the Neck
I am sure that you will prefer to use some kind of sanding drum instead of doing it all by hand. A&er that, use coping saw, chisel, cabinet scraper and sandpaper to trim the ebony headplate to the peghead shape. In the future, if you decide to use the same peghead design, you may want to use a router with a template. Unfortunately (for this opera5on), I have cut almost the en5re peghead shape, and this makes it much more probable that you get chipping problems where the bit exits the wood. To avoid that, you may use a spiral bit and a rou5ng guide (these bits are too thin for using them with bearings). Or, if you use a pa6ern bit, remove as much wood as possible at the end of the peghead where the bit exits the wood.
Next, drill the tuner holes for the headplate, preferably using a drill press (10 mm bit). It is very important that you use a backing for the peghead and press firmly to avoid chipping the ebony. If you want to reduce even more that danger, don't rely on your own strength alone: use some kind of clamping between the peghead and the backing.
Saw off the end of the neck and refine it with sandpaper using a hard sanding block.
63
64
Step 5 - Preparing the Neck
Now you will have to cut the corners at the tenon that the CNC machine couldn't finish (there are three). Use a chisel and a mallet and remove the wood gradually as shown in the first two photos.
This is the tenon a&er cu7ng the three corners.
Finally, smooth the end corners to around a 1/4” (6.5 mm) curvature radius.
Step 5 - Preparing the Neck
Before installing the frets, we'll sand and polish the fretboard. Many makers will polish it a&er the frets are installed, probably because they use some kind of glue for the frets that will mess up the polished wood. I don't use any glue, and I've never had any fret li&ing problems, but you may do as you like: there are many good sources on the subject of fre7ng and there is not a best method yet.
The fretboard should be already sanded to P80 or P120. Go gradually through the sandpaper grades un5l you arrive at P1200, always using a hard sanding block. Watch the ends of the fretboard at the first and last frets: it is easy to sand them more than necessary. Finally, polish it to give it a high luster. I use a small co6on buffing wheel on the drill press, without any polishing compound. You may use some kind of wool pad and work manually or even Micromesh to get the same result.
Clean the fret slots again; compressed air is great, but you can do it with a brush. The finished fretboard, right before installing the frets, should look like the picture.
The fretwire in the kit is already curved to match the curved fretboard surface. In fact, it is curved more than necessary, because that helps the fret ends to seat be6er. Cut each individual fret so that you have an excess of around 5 mm (3/16”) at both sides.
65
66
Step 5 - Preparing the Neck
The fret ends must fit over the bindings, so you must remove a small length of the tangs there; there is a great tool for this at Stewmac, shown at le&. If you don't have one, you can s5ll trim the tangs with a file.
I like to use a file anyway to remove the small burr le& by the tool.
Try to keep as much length of tang as possible, but not so much that the binding may break or unglue when the fret is seated. This is correct.
Step 5 - Preparing the Neck
The most conven5onal tool to seat the frets is a nylon or brass hammer. Hand press the fret at its posi5on and then pound it with a few sharp blows, working from the center to both edges. There must be a wooden block below the pounding area. Work on a sturdy table, preferably right above one of its legs.
For each fret installed, bend down a li6le its ends with the hammer. This will definitely avoid any end gap between the fret and the fretboard. Don't over bend: the moment that the fret starts to bend, you know that it has bi6en the fretboard. Finally, cut the excess using the end nippers. If you find problems using the hammer (I don't think so) there are other alterna5ves (fret presses) at affordable prices. A&er all the frets are installed, file their ends with a long metal file. Do it at a slight angle.
Wri5ng your name on the headstock should be the next step. This can be done in many ways; I use mostly inlaid mother-of-pearl, CNC cut.
67
68
Step 5 - Preparing the Neck
I did that manually in the past; I used (s5ll use) 1.5 mm thick pearl, and cut it with a jeweler's saw. Then I traced the contour of the sawn pieces on the headstock and used a small bit in a small router (Dremel) to open the cavity. Finally, I glued the pearl in the cavity with a glue capable of filling the voids (I s5ll prefer pigmented superglue instead of epoxy). I agree that this is an incomplete descrip5on: whatever I could say in a reasonable amount of space would be incomplete, and you would like to consult other sources anyway. S5ll, if you don't feel confident, you may use a white-ink pen for signing the headstock – if you do it well, it can be very attrac5ve. The cabinet scraper is the best tool for removing the CNC machining marks. When you don't see them anymore, sand the neck with P120, P180 and P220. Use a half-round file for shaping the small area at the peghead that the router could not reach. A&er all these opera5ons, this is the way the neck should look:
Step 6: Main Assembly
By Main Assembly, I mean closing the soundbox. It is not uncommon to have some problems a&er doing this; typically, irregular or not quite ver5cal sides. Hopefully the mold design, with its unusual magnets, will help you avoid these problems.
69
70
Step 6 - Main Assembly
Tools and Supplies Archtop guitars are difficult to assemble because of the arching itself. You'll need to make a flat base like this, using MDF:
No5ce that it is a li6le bigger than the outline of the guitar. I recommend that you make it without a cutaway, as shown. The legs (the three rectangles inside it) raise the plate about 2 inches (50 mm). My main flat base has a cutaway, but it would be be6er without it. It can be used for guitars up to 18 inches. Instead of three it has two legs, glued and screwed, but is equivalent to what I have explained.
Step 6 - Main Assembly
I used a different flat base for the photos that follow, shown at right. Despite the holes, it is the same idea. Apart from that, you must also have four wooden blocks to be used as legs to raise the mold around 2 inches (50 mm). You will need as many clamps as you have (plus two more), a machinist square, a calibrated ruler and a pencil. Also chisels, cabinet scraper and saws, as always. You will need the following supplies:
Wiring guides, #47 Jack, #45, and Jack reinforcing plate, #46 Back, top and sides Glue Thread Adhesive tape
71
72
Step 6 - Main Assembly
Procedure The width of the neck where it joins the soundbox (14th fret) is 55 mm. Thus, its mid line is at 27.5 mm (1.08") from the wall of the cutaway, as it was men5oned when we carved the back plate. Trace it, if not already traced, using a machinist square.
Place the flat plate on the table, and then the mold with the sides inside. Place the magnets and a wooden s5ck of 389 mm (15.31") to press the end blocks apart.
Align the back using the line that you have traced and the middle lines of the sides and back at both ends. Watch the inside o&en, especially if you have carved the back very close to the end blocks. When sa5sfied, clamp the back temporarily.
Glue a few stop pieces like these around the back, using superglue.
Step 6 - Main Assembly
For gluing them, I use a base (a cabinet scraper) with which I push the pieces up against the back; on top of the scraper there is a small wooden s5ck that I use to push them against the side. Be careful to glue the pieces only to the back.
This is the back with the glued stop pieces.
Now you can glue the back (Titebond). Use glue very sparingly, to avoid excessive ooze out. If you use small wooden blocks under the clamps, you won't need as many. I have used a con5nuous block around the contour of the back, that is faster to set than individual lengths. It is more difficult to make, however. No5ce that there are a couple of clamps out of the con5nuous block, pressing directly upon the back. These are necessary to guarantee good gluing pressure at the neckblock and tailblock areas. When the glue is dry, extract the sides from the mold and clean the glue excess with a chisel. If the amount of glue was right, you shouldn't clean much more than what's shown in the picture. Learn as much as you can now: when you glue the top, you won't be able to clean the excess.
73
74
Step 6 - Main Assembly
A&er removing the stop pieces you'll have to trim the overhang from the back plate. If you don't have a rou/ng table or a similar jig, then I recommend that you remove the overhang using manual tools. Don't leave this step for later: if you do, you will not be able to remove the soundbox from the mold a er gluing the top! A rou5ng table has a router below, with its bit protruding through it. The soundbox is kept parallel to the table by means of three "legs" (modified spool clamps) that can be adjusted to any soundbox depth. They keep the guitar above the table at a height a li6le higher than the maximum arching of the plates.
I use a long Flush Trim bit (bearing above the cu6ers). It cuts the overhang fast and cleanly. If you use a rou5ng table, you will have to take into account two very important things. The first is safety: the bit is exposed, so take every conceivable precau/on, including a hood for it (that I don't use, but I should). The second is tear-out. As you know, hand held routers must be fed against the piece ("conven5onal cu7ng"). This is safe for you, but not as much for the piece, that may suffer tear-out. The simplest way to avoid this is to not let the bit reach full depth at first at the problem areas, while s/ll keeping the conven/onal cu1ng direc/on. Don't use old/bad quality bits either.
Step 6 - Main Assembly
This may not always avoid tear-out, especially with spruce tops, that show li6le cohesion parallel to the grain. It will be more effec5ve if you manually remove as much wood as you can from the areas marked "!":
The diagram represents the guitar on the rou5ng table, as seen from above while rou5ng the back. No5ce that he rota5on of the bit is an5clockwise, as corresponds to a router that is upside down. If you want to avoid any possibility of tear-out, follow the feed direc5ons given by the arrows. Rout first the "!" (climb cu7ng) areas, but be extremely alert and prudent: climb cu1ng is not safe for the operator. If you feel uncomfortable doing this, try the alterna5ves explained above; at least, I don't think that you have problems now with the maple back.
75
76
Step 6 - Main Assembly
Glue the wiring guides at the places shown, using superglue. Pass a thread through them and 5e and tape the end securely near the pickup area. This thread will be used to pass the wiring through the guides; if you don't tape it well, it may become extremely dangerous if caught while rou5ng the binding or buffing the finish.
Shape and glue (Titebond) the jack reinforcement plate. No5ce that it is a laminate of two veneers with their grains at right angles. Glue it so that the grains of the three lamina5ons involved (the side and the two lamina5ons of the plate) alternate direc5ons. Drill a hole in it for the jack. Don't use a bit of the final diameter; instead, use a smaller bit and finish the hole with a circular file or a reamer.
Preparing the top for gluing will be a li6le more complicated. The first thing to do will be to measure the length of the neck extension. It must be around 91 mm (3.58"), but it may vary, perhaps because you sanded the neck end differently.
Draw the mid lines inside the neckblock and at the edge of the top, as shown.
Step 6 - Main Assembly
Align the midlines at both ends of the instrument and adjust the distance from the edge of the pickup hole to the outer surface of the sides. It should be the length of the extension that we found plus 5 mm (3/16"). In this case, around 96 mm.
Glue a stop piece, as we did before for the back, to freeze the correct loca5on of the top rela5ve to the sides.
Make a stack as you did for the back, but this 5me don't use the flat base. Instead, put some wooden blocks under the mold so that the back doesn't touch the table. Insert the sides in the mold again, with the magnets.
Align the top again and glue the stop pieces around it, as you did for the back. Before closing the box, be sure to sign the top and/or glue a label to the back (usually visible through the bass-side fhole). The magnets must be in place, but this 5me don't use the wooden s5ck from block to block.
77
78
Step 6 - Main Assembly
Glue the top the same way as the back. This 5me you don't have a flat base below, so you´ll have to find a way of not marring the back, especially with the two clamps that press directly on the soundbox. No5ce that I have used again the "con5nuous block". When the glue has dried, remove the clamps and the end bolt of the mold. A&er that, you will be able to extract the soundbox quite easily. Recover the magnets through the f-holes. Follow the direc5ons given above for rou5ng the plate overhang, now for the top. This is the new feed diagram:
Step 6 - Main Assembly
It is very important that the sides are true. Work with a scraper and sandpaper un5l you feel (touch them with your eyes closed) that they are smooth and regular.
Remove the side wood at the body mor5se. Be very careful with the edges of the top, especially at the bass side. Remove also the excess at the cutaway side. Finally, use the rou5ng table to remove the top overhang inside the mor5se.
Use a fine-toothed file to finish the cut areas.
If you join the neck now (don't insert it fully though), you'll see a guitar emerge for the first 5me. No5ce that the tenon is slightly narrower than necessary, so you'll probably need to shim it.
79
This Page Inten5onally Le& Blank
80
Step 7: Binding & Tuning the Soundbox
Far from being a purely cosme5c add-on, the binding has a purpose protec5ng the edge of the soundbox from small dents. This is more probable if the top, as usual, is made of a so& wood such as spruce. Unfortunately, binding a guitar is not easy, even less an archtop. Tuning the soundbox is one of the most ethereal steps at making a guitar. You'll find makers favoring a lot of different techniques, leading to different final gradua5ons. Each one has a concept of how a carved plate should be and work and, given the great results of so many personal approaches, I don't believe that there is a magical "best" method for this.
81
82
Step 7 - Binding and Tuning the Soundbox
Tools and Supplies Opening a channel for the binding in an archtop guitar is more difficult due to the greater arching of the plates. There are several methods for doing this correctly, usually involving the use of a router that slides on a ver5cal support while the guitar is kept horizontal by means of some kind of adjustable carriage. These machines are quite popular now, and you may purchase one of them at some lutherie suppliers. However, you can use a rou5ng table with similar results, provided that it is big enough for the job. Addi5onally, you may use it for other tasks, as explained in the previous chapters. As for the cu6er, you'll see me use the one from Luthier's Mercan5le, which comes with many different bearings (Stewmac sells a similar one) . If you are going to rout just the top and back of this guitar, there is a simpler solu5on using a ½” flush trim bit, for example the CMT 806.128.11. It has a diameter of 1/2" and a cut5ng length of 1/2". If you replace its bearing (3/16" inner diameter, 1/2" outer) with one of 3/16" ID and 3/8" OD, you'll rout a 1/16" channel which is perfect for the 0.060" binding that I supply with the kit. Small diameter bits like this are great for this, as they limit the damage if you don't keep the guitar horizontal above the table (see the following sec5on). Inch bits are harder to find in some countries. If you have problems, you may use the CMT metric bit 906.190.11 instead, subs5tu5ng its 19mm OD bearing for a 16 mm OD with similar results.
Apart from this, you will need chisels, sandpaper, cabinet scrapers and a small finger plane in case you have one. Nothing new at this phase of the project. You will need the following supplies:
Binding, #9 Closed soundbox Glue (read the discussion below) Tape Sandpaper (P80, P120, P180 and P220)
At the end of this sec5on you will find the procedure for drilling the hole for a6aching the tailpiece bolt. The necessary tools and supplies are explained there.
Step 7 - Binding & Tuning the Soundbox
Procedure As I said before, I use the Binding Cu6er/Bearing kit from Luthier's Mercan5le, using the correct bearing for the supplied binding: the kit, unless noted, has .060" (1.5 mm) thick binding. The guitar is kept horizontal above the table using the same supports("legs") that we used for rou5ng the top and back overhang, except that here we will use only two. The third support will be the ring that surrounds the router bit. Obviously, you will have to move the legs as you progress rou5ng the contour. Do it so that the surface of the triangle defined by the two legs plus the ring is as big as possible. The cu6ers must project around 6 mm above the surface of the ring (a li6le less than 1/4"). I personally don't find it necessary to climb cut to avoid tear out, even in spruce, but take your precau5ons, as explained in the previous chapter. I rout the en5re contour changing three 5mes the posi5on of the legs. When you do this, the channel may show a small step if there is some error in your tool, for example, the legs not having the same height, the table not being flat or something similar. Given that the third support is the ring itself, these discrepancies have a very limited effect, and you will surely remove them with a second pass of the router. Don't disregard these small errors: they are the difference between first and second-class jobs. You have several alterna5ves for gluing the plas5c binding. Weldon 16 must the most common these days, but you may use UHU Hart (similar to Duco). If you use cyanochrylate (super glue), be warned that it is not as easy to use as the slower glues. With it, glue lines will be visible most 5mes, and purfling lines won't be as sharp and uniform as if you use a solvent-based glue. I will use another alterna5ve: plas5c (from the same bindings, for example) dissolved in acetone un5l it has the consistency of glue. Even if you use some other thing, you should have some of this mixture to join white bindings, as you can get completely invisible glue lines. If you make a 50/50 mixture of UHU hart and this plas5c solu5on, you'll get the (for me) best glue for gluing white bindings.
83
84
Step 7 - Binding and Tuning the Soundbox
Use tape for holding the bindings in place while the glue sets. Use a strong one, for example filament tape. Press it against the side, pull strong and then press it against the top or back. Use a good amount of glue, and clean the excess thoroughly before taping the binding in place.
The bindings are long enough to avoid using a joint at the tail. When you arrive at a curved area like the waist or the inside of the cutaway, work the binding with your fingers un5l it has the correct curvature, as shown. You may be tempted to use a heat gun to soften the plas5c, but I don't recommend it: it is very easy to heat the plas5c more than necessary. With the binding in the kit, .060" thick, a heat gun is not necessary. No5ce that I am really using .090" binding here, and even at that thickness a heat gun is unnecessary. This is the top a&er binding it.
Step 7 - Binding & Tuning the Soundbox
The back is bound similarly, but you have a joint at the cutaway corner. Treat it the same way as the joint between the wooden sides. Start installing the binding from the non-cutaway side and trim the excess before gluing the other side. Try to use plas5c dissolved in acetone or, alterna5vely, wet the joint with acetone before gluing.
A&er the glue has set (a few hours should be enough), remove the tape. Do this carefully, at an angle, to avoid pulling wood fibers with the tape; while you don't have to be as careful as with flattops (you'll be carving a recurve later anyway), you may s5ll do a lot of damage.
A rounded cabinet scraper is absolutely the best tool for removing the binding excess. If, while using it, you no/ce that the surface of the binding gets rough, it is probable that the glue is not completely dry.
85
86
Step 7 - Binding and Tuning the Soundbox
For you that have purchased this kit, there are two ways to see the tuning of the soundbox. The first is to simply follow the guidelines here or at some other place. You will get a great sounding guitar, I am sure. Play it, alone or with your friends, and be happy. Skip the following paragraph and enjoy. The second approach is not as easy. Try to listen to what other makers have to say about your work or theirs. Listen also to what good musicians, guitarists or not, have to say about your guitar. Compare it with others, even dissimilar: flat tops, bigger archtops, whatever. Do the comparisons again with different strings, for example bronze. You'll start to discover that you may have been biased, but you are not the only one. Be concerned that, quite probably, there won't be a general agreement on the tone of your guitar. Be ready to hear contradictory opinions from respected makers or musicians. Humans don't agree even with themselves at different moments or situa5ons, and are easily impressed with other things not related to the tone of the guitar: learn from that too; I could tell you many stories about it. Make guitars, as many as you can. Submit them to all those tests. With 5me, you'll develop an objec5ve sense for evalua5ng a guitar, and you'll start to hear things in your unfinished soundbox. You'll have sympathy and probably will adhere to some (or all) of the tribes in this field: those that work mostly feeling the vibra5on with the 5p of their fingers, those that mainly put pressure with their thumbs, the ones that tune the plates while they are not glued to the sides, those that tune the closed soundbox, those who tap the plates, those who excite modes with pure tones, those who analyze the impulse response, the chemists that try to find the composi5on of the varnish, the botanists, even the mys5cs... feel free to listen to all of them: most 5mes there's something interes5ng there, some5mes a lot, but try to take it with a grain of salt. Start scraping the recurve for the top, as shown. You can do it with a gouge, a rounded cabinet scraper or a finger plane, as I am doing here. Check the thickness near the f-hole: you'll be able to es5mate how much wood you are removing from other places. Don't remove wood from above the neck and tail blocks or from the central area of the instrument. Tap the top at different places as you carve the recurve, ge7ng familiar with the change in tone as you progress. For that, you will have to learn to isolate it from other sources of vibra5on, especially the back and the main resonance of the air in the box.
Step 7 - Binding & Tuning the Soundbox
Working on a so& pad will make it easier. The top will lower its pitch, and it will get definite, more musical, as you remove wood from the recurve. Stop when its thickness is around 3.5 mm, as checked through the f-holes. If you go below 3 mm or so, you'll hear that the tap tone starts to change: instead of ge7ng more musical, it will start sounding dull. You must stop the carving before ge7ng there, so you must learn to start hearing that change in the sanded top. That's why you must switch from edge tools to sandpaper when the recurve is at about 3.5 mm. Sand the whole top from P80 to P120, trying to keep it at a minimum out of the recurve area. Do the same with the back. You won't hear this dullness here, so work feeling the change in s5ffness at the recurve, ini5ally a very s5ff area that doesn't deform no5ceably under the pressure of your thumbs. Remove wood un5l you can feel it flexing with a moderate pressure.
87
88
Step 7 - Binding and Tuning the Soundbox
Now it is 5me to drill a hole for the tailpiece at the tail end. No5ce that it will be a6ached to the guitar by means of a bolt that screws through the top and into the tailblock. The bolt must be approximately perpendicular to the tailpiece as the strings pull towards the top of the bridge saddle. Thus, it is necessary that the hole for it is drilled at an angle.
Start marking the loca5on of the bolt: draw a point on the top at the central line of the instrument, 22 mm (7/8") from the edge. Use double sided adhesive tape for s5cking a small piece of wood taken from the truss rod wooden cover. If you threw it away, use a piece of wood around 5 mm (3/16") thick. Place it at around 50 mm (2") from the edge (this is not a cri5cal distance).
Use a 5.5 mm (7/32") drill bit to make a hole in a piece of flat hardwood, around 1/2" (13 mm) thick. Place it as shown, res5ng both on the edge of the guitar and on the former piece of wood. Place the piece so that you can see the mark on the top while looking through the hole. Ask someone to hold it firmly while you drill the hole for the bolt with the same 5.5 mm bit. The depth must be enough for the bolt, around 45 mm (1 3/4"). Finally, sand the en5re soundbox to P220 un5l you see no scratches le& by the previous grades. Do not sand too hard where the pickup, neck joint and bridge will be. Otherwise, you'll have to spend more /me to get a no-gap joint for the pickup ring, bridge and neck. At this stage of the construc5on, you will be able to correct the top for any gaps that you no5ce between it and the bridge foot and pickup ring.
Step 8: Joining the Neck
A good neck-to-soundbox joint is a combina5on of precise woodworking and careful measuring: don't forget any. When you are done, you won't be working on a neck or a soundbox, but on a guitar, so this must be the one of the main milestones.
89
90
Step 8 - Joining the Neck
Tools and Supplies A good chisel sharpened like a razor is the best tool for shaping the neck surfaces where they contact the soundbox. You may use a riffler at the latest stages of the adjustment, but sandpaper will do fine. Carbon paper is a must. If you plan to make more guitars, get some sheets before they don't make them anymore. You will need a long straightedge and a small ruler, but read the procedure sec5on first. There you will find more informa5on on the rest of the tools and supplies. Procedure It has been already men5oned that the neck tenon is a li6le narrower than necessary. For the dry adjustments that follow, use cardboard or paper to shim the joint temporarily (at the treble side of the joint). Confirm that the mid lines for the top and the neck are the same, give or take 1 mm. The photos explain well the first adjustments. You must remove wood from the neck sec5on that projects beyond the tenon un5l you get a decent fit between both parts. This is a work of half an hour at most; if it takes more, then you are probably trying to get a good fit, which you s5ll don't need at this stage. If you haven't sanded the top in excess, you'll no5ce that the underside of the tenon is about 1 mm above the bo6om of the mor5se. There is a similar gap between the end of the tenon and the back of the mor5se. No ma6er the adjustments that you do, keep those gaps. The first photo above shows the removal of wood from the treble side of the neck. That side will separate from the soundbox, as shown here. The bass side is adjusted to the top, as shown in the following page.
Step 8 - Joining the Neck
Now it is 5me to check a few things. The height of the bridge above the top is one of them. For that, I use a jig similar to the one that Benede6o describes in his book. It is a straightedge that rests on the top of the frets and has a projec5ng piece at the end right where the bridge must be located. The height of the projec5ng piece is 1" but, for this model, I prefer to set the bridge at slightly less height, 23 mm (29/32"), which is the value for which the kit was built. If that measurement is greater than 23 mm, you'll have to lower the neck, removing wood from the neck extension. If it is smaller, you'll have to set a new angle between the neck and the soundbox, modifying the neck contact surfaces both under the neck extension and behind the heel. This is more difficult, but don't come to think that you'll find many problems here: if you have built using the mold as described and followed all the advice given in this manual, you'll hardly find large mismatches.
The second thing that you must check now is the alignment of the neck with the axis of the instrument. Use a long straightedge res5ng on the fingerboard edges and extending to the tail end, and mark two lines there. The center line of the instrument must be midway between both. If you find a discrepancy of more than 2 mm, you'll have to modify the tenon. However, as before, don't expect this to happen.
91
92
Step 8 - Joining the Neck
Once sa5sfied with the adjustments, you'll have to refine the joint un5l the gaps are minimal. Before doing that, subs5tute the temporary shim for a permanent one, using the maple veneer that comes with the kit (#37) and se7ng its thickness with a scraper or a sander.
A common technique that facilitates the job of reducing the gaps is to work on smaller surfaces. For that, remove a small amount of wood from the inside (closer to the tenon walls) of the neck contact surfaces, both from the surface that will be above the top (picture) and from the surface behind the heel. This will leave small empty cavi5es between the neck and the soundbox, but you must realize that it's the lateral surfaces of the heel that will keep the neck glued. Working hard to get a good fit on other surfaces do not add to the quality of the joint and will in fact make it harder both to glue and to unglue the neck, if ever necessary. Carbon paper is the best thing for the final adjustments. Use it as shown; when you have a big gap, you may use the chisel to remove the excess, but later you will have to switch to sandpaper or use a riffler.
Step 8 - Joining the Neck
At some point you may have to remove wood from the underside of the tenon to keep an appropriate gap there.
When you are sa5sfied, carefully sand out the stains from the carbon paper and then prepare to glue the joint. Before that, use some masking tape as shown; it avoids the glue ooze out reaching the sanded top and the neck. Use only enough glue (Titebond) for the lateral surfaces of the joint, but be sure to wet both the tenon and mor/se. Press the neck un5l you don't see any gaps, but have long and short clamps at your reach just in case you need to push on some part of the neck: 5ght joints behave badly when they have liquid glue inside. Work fast in any case, finally clamping the work with one or two cam clamps. Once the glue is dry, remove the tape (be careful with the top: you may need a heat gun to avoid damaging its fibers).
93
94
Step 8 - Joining the Neck
The thickness of the heel cap must make the binding at the back totally visible below it, as shown at le&. There shouldn't be side wood visible between the neck cap and the back binding; otherwise, the end grain at the lap joint between the sides will be visible. If you didn't bind the back, this end grain shouldn't exist, because there must be a miter joint, as men5oned in the note in page 23. No5ce that the guitar in this manual has a visible lap joint because, as we said in page 23, its heel is not tall enough. This has been corrected in produc5on kits.
Measure and shape the heel cap (#22) as shown, using a coping saw and sandpaper un5l it has the required shape and thickness.
Glue it, using two clamps to push it against the two surfaces involved. Finally, a&er the glue has set, sand the heel, its cap and the inside of the cutaway un5l all the transi5ons are smooth.
Step 9: Finishing
Guitars are not as sensi5ve to the type of finish as other stringed instruments seem to be. A good finish should help you create a uniform, thin, transparent, smooth, repairable and durable coa5ng. With so many requirements (and the list is not complete), you will understand that there is not a perfect finish. In this sec5on, my objec5ve is more trying to help you decide what to use and give you some general rules than explaining in detail some of the alterna5ves.
95
96
Step 9 - Finishing
There are a lot of finishes that makers and factories use for guitars. These are all common:
Nitrocellulose lacquer Waterbase Shellac Polyurethane (two-component) Polyester Conversion Varnish (Acid Catalyst Lacquer)
What follows is oriented to finishes that coat the wood completely, either with a shiny or sa5n look. There are oil finishes that are more or less absorbed into the wood and which many players like, but I won't talk about them. Ideally, the finish must have the following characteris5cs: Transparency.- All the finishes men5oned above rate very high, including the best modern waterbase (not so for the old formula5ons).
Repairability.- Nitrocellulose and Shellac are repairable as they harden by evapora5on of their solvents instead of through a chemical reac5on. The new coats of finish fuse with the old, forming a single thicker coat. The other types of finish are difficult to repair without leaving telltale marks. In general, the more resistant a finish is to chemicals, the harder it is to repair. Low Toxicity.- This is desirable for you and for the environment. Waterbase uses mainly water and Shellac uses ethanol as its only solvent, so these must be the least toxic finishes in the list. The other finishes are all dangerous for your health or the environment.
Some finishes have a greater solid content than others, so they will emit less vola5le compounds per finished instrument. Polys and Conversion are like this. Nitrocellulose is exactly the opposite. HVLP guns can be used to improve this aspect. Low Flammability.- Among those men5oned, Waterbase is the only finish that is not flammable. Ease of applica5on.- Shellac is usually applied with a pad, but it is not a technique that you'll master easily. The other finishes are usually designed for spray gun applica5on, but you can try
Step 9 - Finishing
brushing at least some of them. Waterbase can be applied carefully with a foam pad, trying to avoid any bubbles. Nitrocellulose, if thinned with an adequate thinner, may be applied with a conven5onal brush, but be warned that it won't be easy. Some finishes require expensive guns. Conversion uses an acid catalyst, which will probably require a stainless steel gun (or, at least, stainless steel fluid passages). Some finishes, especially the polys, cover the wood very well to the point that pore filling is unnecessary even with porous woods such as mahogany. Short drying/curing 5me.- Nitrocellulose and Conversion varnish rate low here. They need at least three weeks, although Nitrocellulose will keep shrinking for years. Most waterbases are ready for buffing in less than two weeks, while polys may be ready the same day. Tradi5on.- Nitrocellulose is by far the most tradi5onal finish for archtop guitars. Shellac has been used tradi5onally for the best classical guitars, but it doesn't have a tradi5on for archtops. All the other finishes can be considered as non-tradi5onal, modern alterna5ves. This is not related to the quality of the finish, but it may be important for some players. Good Adhesion.- I have had problems with Waterbase finishes, reac5ng to the perspira5on of some players and then peeling off. This may be a thing of the past (I am talking of waterbase finishes designed around 2002 but sold specifically for guitars). Polyurethane and Conversion may also suffer adhesion problems, but most 5mes that seems to be related to excessive film thickness.
Some finishes may show incompa5bility issues with some other products. For example, Conversion varnish shouldn't be used over Shellac. This is surprising, because Shellac is the first product that finishers think of when they suspect adhesion problems. The moral is: always refer to the technical documenta5on. Good Durability/Resistance to Chemicals.- Shellac is by far the less durable. It doesn't have any resistance to most common chemicals and is very prone to abrasion. Consequently, it needs maintenance to the point that some players even learn do it themselves.
97
98
Step 9 - Finishing
Nitrocellulose is a tougher finish, more resistant to chemicals than Shellac (not much, though), but it loses plas5cizers with 5me, becoming very bri6le and cracking easily ("cold checking"). This can happen to almost any type of finish if applied too thick, but nitrocellulose alone without its plas5cizers is extremely bri6le . Take this into account when choosing the right Nitrocellulose lacquer: those designed for furniture are too bri6le, even when they are young, and are not adequate for guitars. Some waterbase finishes are tough, some are not. There is a lot of varia5on in the formula5on of waterbase finishes. Most have fair resistance to most common chemicals. The other finishes are tough and have excellent resistance to most chemicals. The bad consequence of this is that they are very hard to strip. Some finishes tend to yellow with 5me, but most modern formula5ons don't suffer that problem. Good Sandability.- Some finishes are easier to sand because they are scratched more easily. This is not a good thing, as that means that they can also be easily scratched in use; however, some finishes sand easily because the dust doesn't s5ck to the sandpaper so easily. Some finishes are be6er than others in this aspect. Easy to use.- All the finishes men5oned must be applied within certain margins regarding temperature and humidity. Waterbase, Conversion varnish and the polys are the most sensi5ve, but you will have to be careful with all of them.
Some finishes come in two parts that must be thoroughly mixed before the applica5on. Conversion varnish is like that, but it is not difficult to use because the ac5vated lacquer will remain usable for more than one day ("pot life"), which is enough for finishing a guitar. There exist precat single-component lacquers, where the catalyst starts the reac5on a&er reaching a given concentra5on, i.e., when enough solvent has been released, but we won't men5on them here anymore.
Polys are different: it will be a ques5on of minutes before the mixture becomes unusable, especially for Polyester. To avoid this, there are Polyester lacquers that are ac5vated by UV-light. The
Step 9 - Finishing
drying cabins are expensive and out of the reach of most small makers, though. Cleaning the spray gun or brush may be awkward for some finishes, and that is complicated even more when they have a very short life, as most polys. Fusing .- As the finish will be sanded and buffed, it must have enough thickness that must be built coat a&er coat. The coats must fuse together or you may get a nasty effect that is known as witness lines. Only evapora5ve finishes fuse perfectly, but all the other will fuse enough if you apply each coat within some 5me window. Sanding right before applying the following coat will help exposing fresh finish and improving the mechanical bond between coats.
Smoothness.- Some finishes feel a li6le s5cky. This is a common problem with Nitrocellulose, and less with Polyurethane, Polyester and Conversion varnish. Few players will complain, though. Long Shelf Life - Most Nitrocellulose lacquers specify a shelf life of around 1 year, but most makers will tell you that it can be used a&er many years without any problem. Shellac has an indefinite shelf life when undissolved. Once dissolved in alcohol, it will be suspect a&er six months: old shellac doesn't dry well, staying gummy, and will ruin any other finish if used as a sealer below it. The other finishes must be used as indicated in their technical documenta5on. :::
A good finish is not complete without a good finisher that achieves uniform and thin coa5ngs. Uniformity is hard to achieve, and it can be controlled be6er using a brush or a pad. If you use a spray gun, you will discover sooner or later that you are not being uniform, coa5ng some areas less than others. There are ways to improve on this, and finishing many guitars will help, of course. This may not be very useful if you plan to make a few, so another technique is to 5nt the lacquer (a drop of concentrated dye will be enough for 1 quart/liter) if it is totally transparent. If the guitar has white bindings, it will be easy to discover thinly finished areas before you get a sandthrough. Finishes look more natural when they have a slight amber hue, much be6er than the transparent look or the bluish hues of some
99
100
Step 9 - Finishing
waterbases. Another technique is to lightly sand between coats, no ma6er if the finish needs it or not. You will discover and then correct any thin area while the finish is fresh (at a 5me when the coats will fuse even for reac5ve finishes) instead of finding it a&er a month's drying (too late for invisible repairs in reac5ve finishes). The thickness of the film must be kept at an absolute minimum. Tone is nega5vely affected by thick finishes, but they also affect the integrity of the coa5ng, which may be severely weakened. A&er sanding, buffing and polishing, it must be below 100 microns (4 mils). For this, if you use a spray gun, I recommend that you place some cardboard under the pickup and f-holes. Check with a caliper from 5me to 5me, no5cing that the finish will shrink more if it is totally or par5ally evapora5ve. Aim at around 150 microns (6 mils) before sanding. ::: You will find a lot of informa5on on finishes, especially nitrocellulose lacquer, at many places. However, I will show you a different alterna5ve, conversion varnish (called acid catalysed lacquer in UK). Few use it, partly because it has the disadvantage of emi7ng formaldehyde while it hardens, but if you have a warm ven5lated place it is a great finish and very easy to use. I use Morrells 5901/450, a general purpose high solids (45%) low odour conversion varnish, made in UK (so it should be called acid catalysed lacquer instead). For applica5on, I use a mid-priced conven5onal gun, with a 1.6 mm 5p. No5ce that this finish has acid in its composi5on, so it must be a gun with stainless steel fluid passages. A HVLP gun will save lacquer, as the finish droplets will not bounce back as much. The guitar must be sanded very well to P220. The parts of ebony and other oily woods must be sanded to P120; otherwise, you may find adhesion problems. If you used an orbital sander, you may have spiral marks that are almost invisible un5l a&er the finish is applied. Sanding by hand may also leave marks. The solu5on is to make the last sanding by hand, working methodically, and using reflected light to discover the possible marks before it is too late. Also, try to find small holes or dents, for example around the mother-of-pearl inlays. Drop fill them with some superglue. A&er this, the dust must be removed, for which a compressed air gun is a great tool. Mask the fingerboard and nut channel with masking tape. It must
Step 9 - Finishing
be fi6ed without leaving cavi5es, especially near the frets; otherwise, the lacquer may get inside. Use a piece of drinking straw to cover the threads of the truss rod. Finally, inflate some balloons inside the soundbox through the f and pickup holes, and place some cardboard above them; this is a simple and effec5ve method for avoiding lacquer into the soundbox. That cardboard can be used to measure the thickness of the coa5ng as explained above. Prepare the lacquer by mixing the two components. You'll need around 600ml (conven5onal gun) to which you must add a drop of ColorTone Vintage Amber dye or equivalent. Without it, this finish is absolutely colorless. Once mixed, the lacquer remains usable for around 36 hours. The wood species tradi5onally used for archtops don't need any pore filling, so we will simply spray the same finish on the guitar, coat a&er coat. Start early in the morning, spraying a light first coat of finish. A&er around one hour, examine the guitar for possible sanding marks that went unno5ced; if you find some, this is your last opportunity to sand them. Apply three more coats, wai5ng around 2 hours and sanding between them. Wait five or six hours, sand again and apply the fi&h coat. Wait two hours, sand and apply the last (sixth) coat. Two or three days later, when the finish is hard enough but not totally cured (it needs about three weeks), sand with P600 and then turn to the following sec5on and do what must be done before polishing and buffing. When totally cured, sand with P800. This finish is extremely easy to sand dry, as it doesn't clog the sandpaper (I use 3M Gold). Sand with P1500 (for example, Micromesh), and then use a drill with a foam polishing pad and liquid compounds of different grits, the last step being a swirl remover. Alterna5vely, if you have a buffing arbor, machine buff with Menzerna 38, 16 and 6 (in that order) and, finally, use a drill with a foam pad to apply swirl remover. Purely manual methods are hard work; if you prefer them, Micromesh pads will be helpful.
101
Summarizing, Morrells 5901/450 can be applied the same as nitro, and using a similar schedule. Sanding is easier, and the coa/ng is more resistant in all aspects, but its chemical resistance, being high, is not as high as in polys: if you need to strip it, it will be easy with a commercial stripper. This is good news for a reac/ve lacquer, but that's not all: if the finish needs repair, it will fuse perfectly without leaving any telltale mark! Regarding flexibility, I have tried other conversion varnishes and they are not flexible enough to be applied on guitars even in very light coats, but this one is amazingly flexible. It has some nega/ve characteris/cs, of course: it must be applied with a more expensive stainless steel gun, it is more sensi/ve to contaminants (water, oil) in the compressed air and it emits formaldehyde while it cures, but if you find a way around, you'll use the, in my experience, absolutely best product for finishing guitars.
102
Step 10: Fittings And Final Adjustments
This chapter will cover the main items that make the guitar playable and useful for a musician. Even having a fine tone, any player will dismiss a guitar if it has problems with ac5on or intona5on. Try not to rush things now that it is almost finished: give all this the 5me that it deserves.
103
104
Step 10 - Fittings & Final A djus tments
Tools and Supplies There are lots of tools for doing fretwork. Here we will use a long flat metal file to level the fret tops; if you have one, check its straightness, as files are not precision-made to be straight. I will use a fine diamond fret file and a triangular file with smoothed corners; these are tools that many old-5me makers don't use. I will also use masking tape, sandpaper (P600, P800, P1200), a permanent marker, a good thin straightedge and the Dremel tool with the accessories 414 (felt polishing wheel) and 421 (polishing compound). You'll need to polish some wood (ebony) parts. You may use Micromesh abrasives or a small cloth wheel in a drill. The channels for the strings in the nut and bridge saddle can be done with a miniature saw, but it is much easier to use a few nut files. You'll need a small round file (1/8" diameter, 3 mm) for opening a small window at the pickup ring for the wiring. You'll also need screwdrivers drill bits in different diameters and, as always, sandpaper, scraper, chisels, etc. For details, refer to the Procedure sec5on. You will need the following supplies:
Bridge, #17 Tailpiece, #18 and bolt, #31 Pickup ring, #19 and screws, #30 Finger rest, #20 and its parts, #32, #33 and #34 Truss rod nut cover, #21 and screws, #28 Strap holders, #36 Electronics (#43, #44, #45, #48) Glue (Titebond, Super glue) Naphta (lighter fuel) Sandpaper (P80, P120, P180 and P220)
Step 10 - Fittings & Final A djustments
Procedure These opera ons can be done before the finish is ready to be sanded and buffed. Some of them may scratch the finish, so doing them now should be the rule.
Dressing the Frets Scrape or sand the edges of the fretboard to avoid the lacquer coming off the fretboard edge when you remove the masking tape. Once removed, no5ce that you may have some lacquer over the fretboard; remove it carefully with a razor blade. Put masking tape between the frets and draw a line on top of each fret with a permanent marker. Install the truss rod nut and washer and 5ghten it around a quarter turn.
Check with the straightedge if you have some fret or group of frets higher and use the file to correct it. Both the straightedge and the file must be used more or less parallel to the axis of the instrument or more or less following the lies of the strings (the difference between both methods is 5ny). Check frequently with the straightedge un5l all frets have been at least touched from side to side. Do not try to use the file without measuring first where to file, and watch closely the first fret. It is easy to file it too much, an error with bad consequences; to avoid that, be very careful when you get close to the nut, pressing on the file always above the fretboard, far from the first fret.
105
106
Step 10 - Fittings & Final A djus tments
When you are sa5sfied with the leveling, use a wooden block and sand (P600) to remove the nibs of lacquer that adhered to the fret ends. Then use the fret file to recrown the frets. Stop when you see a thin line untouched by the file.
Use the triangular file to smooth the fret ends, rounding the faceted edges at the ends of each fret. Some makers round the fret ends completely; this will be easier if you use a rectangular fretend dressing file instead.
The two images show a fret end before and a&er being dressed with the triangular file. Four or five strokes at each side of the fret are enough.
Step 10 - Fittings & Final A djustments
Sand the frets, star5ng at P600 and ending at P1200.
Polish each fret with the Dremel felt wheel #414 and #421 polishing compound; do not spend a lot of 5me at each fret, as they can heat in excess. It is be6er to work with a group of several frets, going from one to another cyclically. Be warned that the #421 compound is not very fine. If you use finer compounds they will give an even be6er mirror-like finish.
Clean all the frets with a piece of cloth and naphta (lighter fuel). Remove the masking tape and con5nue cleaning everything un5l you don't get any more polishing residue on the cloth.
Fi1ng the Bridge to the Top Before star5ng this procedure, mark the bridge posi5on on the top. Its center will be at a distance of 322 mm (12 11/16") from fret #12:
107
108
Step 10 - Fittings & Final A djus tments
If you have followed the instruc5ons, the foot of the bridge must be very close to its final shape. Place the bridge foot at its loca5on, well centered and oriented. There are marks on it that will help you determine its correct orienta5on, but you'll easily no5ce that an inverted bridge will be very poorly fi6ed to the top. Mark its center for reference and then use carbon paper to determine the high spots, as shown. Remove them with a scraper un5l you have a good fit everywhere. Sand and polish the bridge foot (except its base) and saddle, from P120 to P1200, then buff them as you did for the fretboard.
The bridge posts must be sawn off to around 22 mm (7/8"). File the sawn ends un5l rounded and smooth. To screw the posts to the bridge foot, use the acorn nut and the thumbwheels as
Step 10 - Fittings & Final A djustments
shown, turning the acorn nut to screw and the thumbwheel to unscrew. The wood is threaded, but you will find some resistance, which is fine. However, if you find a lot, unscrew the post and make it shorter (it should protrude around 1/2" (13 mm) above the foot). Check that the posts are ver/cal and parallel. Open the channels for the strings in the saddle. It will be easier if you use nut files, but you may use some miniature saw and even guitar strings. Don't go too deep: it is enough for the string to be buried down to its center. It is very important that you file at an angle, more or less following the line from the saddle to the tailpiece. Otherwise, the strings may ra6le. Use the following distances between the string slot centers; with them, it's the space between each pair of adjoining strings that is constant (these numbers are valid for the most common string gauges found in jazz guitars): 6th to 5th: 6th to 4th: 6th to 3rd: 6th to 2nd: 6th to 1st:
11.5 mm 22.8 mm 33.9 mm 44.8 mm 55.5 mm
Fi1ng the Pickup Ring to the Top If you didn't sand the pickup area in excess, the fi7ng of this part must be great already. Otherwise, use carbon paper the same as you did for the bridge foot. Try to get at least a decent fit here; otherwise, there's a real danger of breaking the ring (or, in some cases, the top) when you 5ghten the screws.
Use a small circular file to, open a hole of around 1/8" (3 mm) diameter at the treble side of the pickup ring, as shown. It will be used to pass the wiring from the soundbox to the finger rest. Then as with all the ebony parts, sand (P120 to P1200) and buff as you did for the fretboard.
109
110
Step 10 - Fittings & Final A djus tments
No5ce that the ring has not the holes for the pickup height screws; drill them from below, using the pickup as a template. Don't drill without clamping a wooden base to the ring, as shown. Then mount the pickup in the neck ring.
Posi5on the pickup centered in its hole. A straightedge following the two edges of the fretboard will be very helpful. At this stage, you will probably discover that the pickup cover is wider near its bo6om. Many pickups with metal covers have this problem, but it is not important for most solid guitars, which have them buried. Pickups in archtops are considerably higher above the top; in some cases, you may have to cut the solder at the back of the pickup, clamp it to close it and then resolder it. You may also file the hole for the pickup in the top of the guitar. Drill the four holes (1.5 mm, 1/16") to fix the pickup and its ring to the top. Fi1ng the Finger Rest Trim and glue (Titebond) the ebony spacer (#33), the reinforcement strip (#34) and the poten5ometer (#43) under the finger rest, as shown in the figures. The reinforcement strip will avoid fractures like the one shown in the diagram, so don't forget it. No5ce that the finger rest shown throughout this manual is shorter than yours, which also has a rounded edge. With this new version, you'll have more room between the poten5ometer and the guitar top.
Step 10 - Fittings & Final A djustments
When the glue has set, drill two holes for the installa5on screws (1/8", 3.2 mm diameter) as close to the finger rest surface as possible, but leaving enough room for the screw heads.
Cut the corners of the notch for the pickup ring that the router couldn't reach due to the radius of the cu6er.
With the pickup ring s5ll screwed to the top, posi5on the finger rest as shown. It must have the same angle as the neck, as if it was an extension of it, and its top must be in line with the top surface of the pickup ring. If you fail doing these adjustments, you may compromise the room for the poten5ometer. Mark the loca5on of the holes at the neck (you'll need a thin and long marker for this).
Drilling the holes for the finger rest at the side of the neck is easy with a long drill. I use a miniature drill (found in hobby shops) with an extension a6ached and then inserted into a bigger manual drill. Use a 2.5 mm (3/32") bit.
111
112
Step 10 - Fittings & Final A djus tments
Use a long screwdriver to a6ach the finger rest to the guitar. Soap the threads if you find the screws are too hard. If you find some misalignment, enlarge one or both finger rest holes with a miniature file.
Remove the finger rest and the pickup. Sand and buff the surface and edge of the finger rest the same as you did for the other ebony parts. Don't let the dust reach the poten5ometer: protect it with tape.
Preparing the Tailpiece The underside of the tailpiece has recesses for the string ball ends, as shown, but the channels for the strings on the other side are not deep enough to reach them. Use a miniature file to correct that (first photo, next page). Finally, sand and buff the surface and edge of the tailpiece the same as you did for the other ebony parts.
Step 10 - Fittings & Final A djustments
Preparing the Nut In a previous step you thicknessed and polished the nut sides. Now you will trim the nut to its correct height and width, which you'll do with the help of a half pencil. This is built from a pencil cut lengthwise so that its base is flat, using it as shown.
Cut and sand the excess leaving some material above the pencil line. At the 6th string, that excess (A in the figure) must be around 1 mm; at the side of the 1st string, it will be around 0.5 mm (B in the figure).
The top of the nut must be more or less at a plane parallel to the peghead, and its upper corners must be rounded slightly. The ends of the nut are cut flush with the neck surfaces.
113
114
Step 10 - Fittings & Final A djus tments
I recommend that you open the string slots using nut files. If you use a miniature saw, try to keep the bo6om of the slots round. There are two principles that are generally accepted for determining the posi5on of the string slots: 1.- The outside edges (not the centers) of the 6th and 1st strings must be at around the same distance from their corresponding fretboard edges. As for most common string sets the sixth is around 1 mm thicker than the first string, the center of the slot for the first string must be around 0.5 mm closer to the edge of the fretboard. 2.- It is the space between each pair of adjoining strings that is constant, not the distance between their centers. Thus, the centers of the thinner strings are closer than the centers of the thicker strings. The following procedure fulfills those requirements for 1 3/4" nuts and the string gauges most commonly found in jazz guitars: - Mark the slots with the thinnest nut file at the following loca5ons: From fretboard edge to center of 6th string: 4 mm From center of 6th to center of 5th: 7.8 mm From center of 6th to center of 4th: 15.5 mm From center of 6th to center of 3rd: 22.8 mm From center of 6th to center of 2nd: 30.0 mm From center of 6th to center of 1st: 37 mm -Widen each slot using files increasingly thicker. For example, use the file for the 2nd string to widen the slots for the 2nd to 6th strings. This will give you more control and the ability to correct the misplaced slots. And remember, don't file deeper than half the diameter of the string. Polish the whole nut (except its base) the same as you did when you polished its sides.
Step 10 - Fittings & Final A djustments
Preparing the Electronics Clamp and then solder two terminals to the single-conductor shielded wire. It must have a length of around 50cm (20").
Insert the terminals into the small connector, ground (jacket) terminal at le&.
Do the same for the large connector, using 15cm (6") of two-conductor shielded wire. Posi5on the ground (jacket) terminal at right, and the other two wires (dark and clear) as shown.
The pickup must be connected to the male plug. The hot from the pickup is connected to terminal #2. The ground from the pickup is connected to both #3 and #4. Addi5onally, there is a wire connec5ng #1 and #5 together.
115
116
Step 10 - Fittings & Final A djus tments
This is the way to make the connec5ons inside the guitar.
The short two-conductor shielded wire must be connected to the poten5ometer. The jacket up, the dark wire at the center and the clear terminal down. No5ce that the poten5ometer will work opposite as usual: seen from above, the volume will increase when turned counterclockwise. Given the side that is glued to the fingerboard and its logarithmic taper, this is the way to go. Anyway, as it is different from conven5onal pots, players don't find it wrong.
Put two or three drops of super-glue between the wire and the finger rest. Remember that it must reach the hole in the pickup ring.
Screw the wheel and glue the self adhesive piece of felt. With it, the pot won't mar the top if the finger rest is bent excessively.
Step 10 - Fittings & Final A djustments
Check that everything fits well. If necessary, file a small channel in the top for the wire to pass more easily.
The following opera ons must be done aer the finish has been sanded and buffed.
Install the tailpiece bolt, pu7ng some soap on the threads. It must protrude around 10 mm (3/8") above the guitar top.
Reach the thread that passes through the wiring guides and superglue it to the bare end of the single-conductor wire, as shown.
Pull the thread and the wire will pass through the guides.
117
118
Step 10 - Fittings & Final A djus tments
Solder the female jack and use a piece of wire to guide it into its hole, as shown. Tightening the jack without having access to the guitar inside can prove impossible. If this happens, you may find that Frank Ford's "Jack The Gripper" is the tool to use.
Make the connec5ons and secure the wires with a nylon 5e. Now you can screw the finger rest and pickup in place.
The machines can be installed two ways, as shown. Whatever you choose, keep them symmetrical. Always drill pilot holes for the screws. Install the strap holders. One of them must be placed at the tail where the sides join; the other, either at the heel or at the back of the guitar. In any case, always drill a pilot hole preferably using a manual drill and a 3 mm (1/8") drill bit. Stringing up the first /me This is an electric jazz guitar, and as such it should be equipped with flat-wound electric guitar strings. A medium gauge common for jazz is 13-56, but feel free to experiment. Install the nut, but don't glue it yet. With the bridge more or less in place, the tailpiece on and a&er 5ghtening a quarter turn the truss rod nut, you can install the strings. Do it symmetrically (1st and then 6th, 2nd and then 5th...). Tune the guitar. With the bridge thumbwheels, set the strings at a height of no more than 1/8" (3 mm) above the last frets.
Step 10 - Fittings & Final A djustments
Trimming the Nut Slots Guitarists enjoy guitars with nuts as low as possible, not only because they are easier to play but because they tune be6er at the first frets. However, there is a 5ny difference between a comfortable nut and one that makes open strings buzz. I would recommend you to take some risks here, it's well worth it. For each string, loosen it, file the slot, 5ghten it again at or near its tension, and measure the distance between it and the first fret with a feeler gauge while having it fre6ed at the sixth fret, near the bar of the fi&h fret. Measuring while fre7ng takes the ac5on out of the equa5on. The measured distance should be less than 0.1 mm (0.004"), the thickness of a piece of paper. Work carefully: two or three file strokes may separate you from having to make a new nut. A&er having done this, you can glue the nut in place. Use a couple drops of Titebond on each contact surface (fretboard and nut bottom). To improve adhesion, sand slightly some of its polished surface. Checking and adjus/ng the Relief Necks work be6er when they have a slight relief instead of being perfectly straight. They must show a concavity that is deeper more or less at mid length (around fret #7). To measure it, press one of the middle strings simultaneously at the first and fi&eenth frets. Get the help of someone to measure the gap between the bo6om of the string and the 7th fret; it should be around 0.010" (0.25 mm). You can measure this using a guitar string as a feeler gauge. If it is greater, 5ghten the truss rod. If smaller, loosen it. Always do it a quarter turn at a 5me and then let guitar rest: a&er a guitar is stringed up for the first 5me, changes are slow but develop for days or even weeks. A&er se7ng the relief, always check the bridge height. A general rule says that it must be as low as possible, so that the strings don't buzz when the player uses the strongest a6ack in his playing. Anyway, this is extremely up to the individual, and many jazz players like to have high ac5ons. Always that you modify the bridge height, adjust the bridge compensa5on. Adjus/ng the Bridge Compensa/on Wooden saddles don't give perfect intona5on for all the strings. However, if you place the bridge so that the second and fi&h
119
120
Step 10 - Fittings & Final A djus tments
strings tune perfectly, then the others will be very close to being perfect too. Check if the natural harmonic for the second string in fret 12th is the same as the fingered note in that same fret. If the tuner (or your ear) finds that the fingered note is higher than the harmonic, the bridge will have to be moved closer to the tailpiece. Otherwise, move it further away from the tailpiece. Check the same for the fi&h string, but this 5me don’t move the whole bridge, as you must not modify its posi/on for the second string. Pickup height Humbuckers can be placed between ample distance margins rela5ve to the strings. A general rule for neck pickups says that there must be a distance of around 3/32" (2.5 mm) from the bo6om of the strings to the top of the pole pieces when the strings are depressed at the last fret. This must be set with the height screws; the pole pieces can be adjusted individually, but this should be done only if you find some strings louder than others, for example if you are using bronze-wound strings. Truss Rod Nut Cover When the neck has stabilized, you can install the truss rod nut cover, which you must have sanded and polished as usual. Place it centered, touching the nut and, as always, open pilot holes for the screws. Congratula ons! By now you probably have a guitar that you are proud of. Keep it in a good hard case, far from temperature and humidity extremes and enjoy it for years to come!
Bibliography There are many books on the subject of guitar making, but I consider that you'll benefit mainly from these four: - Erlewine, Dan. Guitar Player Repair Guide. Backbeat Books, 2007. - Benede6o, Robert. Making an Archtop Guitar. Centerstream Publica5ons,, 1996. - Hoadley, Bruce. Understanding Wood. Taunton Press, 2000. - Dresdner, Michael. The New Woodfinishing Book. Taunton Press, 2000. The book by Erlewine, a master repairman, will answer a lot of your ques5ons, especially those related to guitar electronics, setup and fre7ng. If you want to complement the book with his DVDs, that will be great too. The book by Benede6o, a master archtop maker, is the only one describing the construc5on of an archtop guitar. Again, there is a collec5on of DVDs that is a great complement to the book. The two other books are not guitar related, but I strongly recommend them: a thorough knowledge of wood and finishes is paramount when it comes to avoid future problems. Finally, there is a book by Bill Cory, Complete Guide to Building Kit Acous/c Guitars, available at www.KitGuitarManuals.com both in printed and e-book forms. It deals with flat-top acous5c guitars, but you'll find a lot of helpful informa5on in it.
121
122
Safety Issues - Read First Magnet Safety Liability we do not assume any responsibility for damage that has been caused by the improper handling of magnets. With the purchase of these magnets, you confirm that you have read and understood the following warnings. Danger of breaking or chipping NdFeB magnets can break. The most common cause of breakage is when two magnets are allowed to collide. It is also conceivable that chips of the magnet will fly due to such a collision. You should wear gloves and protec5ve glasses when handling magnets. You should always handle magnets with cau5on and never let them collide together. Danger for children These magnets are not toys and can be dangerous in many ways. Keep them out of the reach of children. Crushing When these magnets are brought close enough together, fingers can be quickly caught between them causing blood blisters or cuts. Remember: always wear gloves. Magne/sm - danger for appliances Keep a safe distance between the magnets and all appliances and objects that can be damaged by magne5sm. This includes, amongst other things, television and computer monitors, credit cards, diske6es and other data devices, video tapes, mechanical clocks, hearing aids and loud speakers. Pacemakers can be disturbed by large magnets - in case of doubt, exercise cau5on. Processing, drilling, sawing, fire Never a6empt to cut or drill into a magnet. First, the magnets will break. Second, this cu7ng or boring will produce a dust that is easily flammable. Keep the magnets away from open flames and any heat sources. The magne5za5on of neodymium magnets reduces quickly at temperatures of more than 80 degrees Celsius. Nickel allergies These magnets are nickel-plated. Nickel is a metal which can cause an allergic reac5on in some people
123
