Intro: How to Make an Acoustic Guitar
Look I'm building a guitar!
You're doing what now?
- Quite literally everyone else
Hi and welcome to my longest woodworking project so far. Let me tell you the story of how I ended up building an acoustic guitar with only little woodworking skills, no previous instrument building experience, almost no fancy power tools and definitely no clue what I was getting into. Oh and I don't know how to play the guitar
I was cruising the interwebs when I stumbled upon this amazing, exactly one-hour-long documentary about one of the great modern acoustic guitar luthiers, Michael Greenfield. Whether you consider making a guitar or not, this documentary is a great way to spend an hour: I found it riveting and his craftsmanship in nothing short of art.
When I get to experience something beautiful, it sometimes happens that a part of me thrives to participate of that thing even for just a moment, to try and emulate what I just saw, heard or tasted. Find the recipe to try and remake that great meal I just ate for instance, or ... craft that guitar. Now I'm very aware that I'll never make anything as good as the original. I guess my desperately Cartesian mind is trying to decompose and process those beautiful things from the inside to try and rationalize what makes them resonate with me in the first place. Enough introspection. Let's get crafting.
Overall, I estimate the time spent working physically on this project in the 300 hours ballpark. That's 10 hours a day every day for a month, which made me understand the price tag on handmade instruments. However, this does not take in account all the research, reading, material sourcing etc. which account for about the same amount of time, I'd say.
Depending on where you source your wood and what grade you're after, and assuming you already have the necessary tools (see below) this project could set you back anywhere from 200 to 1000 euros (or dollars). This is more than an entry-level acoustic guitar but damn, I love this one so much it makes me play the hell out of it every day! And actual musicians have told me it sounds better than most mid-price-range acoustic guitars out there, which is more than I could have hoped for..
TL;DR: Let's make a guitar in a garage and drink whiskyyyyyyy
Note: Pro tip, there are a LOT of pictures in this i'ble, most of which will be invisible unless you click the "X more images" button. And most pictures will be annotated with tips and tricks or simply descriptions. Don't miss out on those :)
By the way, this is an entry in the woodworking contest. If you deem it worthy, please hit me up with a sweet vote! Cheers :)
Step 1: Tools and Other Materials
There are no bad tools, only poor craftsmen.
- French proverb by some cretin who obviously never used a bad plane
Well to be fair there is some truth in this statement but not in the first sense I could think of. I guess this is a somewhat similar statement to "It's a poor craftsman that blames his tools" which could be understood in the sense that a good craftsman will pick the right tools for the job and save up for a few nice tools if he can, rather than buy a bunch of poor ones. Either way you see it, here is the bare minimum tools I reckon are needed for this project. Most of them are very common woodworking tools which may represent an interesting investment if you are already working wood. (Which you probably should if considering guitar building!) The tools that are specific to guitar making are underlined. (Notice that it's just the book! Every single other tool I used was a common woodworking tool. No fancy jigs or anything, just the one book. This makes the build very affordable and accessible to anyone with a casual woodworking workshop.)
Here's one piece of important advice: do not simply hope for a list of which tools to buy and go buy those tools. That goes for any job but is even more important when considering what may very well be a one-off project such as this one. There are two reasons why this is a bad idea. First, money. Straightforward. Second, not having the exact right tool for a specific job will make you smarter. Improvisation is important and there are many ways, and therefore many tools, to complete a task. You will pick one way to carry that task that employs either a tool you own, a tool you'll buy/borrow or a tool you'll make. I always try to avoid the second option.
In the end, it is only by building the guitar over and over in your head that you will know what tools you need and what tools you really want for each step. Using tools you want to use is a very overlooked part of any project. Sure, that fancy orbital sander will do the job I need to do and it'll do it fast. But do you enjoy using it? I don't. What I love to use, when possible, is a card scraper. It allows me to feel the wood and I really enjoy the sharpening and burnishing.
Anyways, here is what I ended up using (Brand, comments):
Good chisels (Kirschen)
Card scrapers (Kirschen as well)
A jack plane (Veritas)
A dovetail saw (No name from amazon)
A hand drill (Makita)
A coping saw/scrollsaw (Old stuff from my granddad and my great great grandfather)
Some files and rasps (same)
A bunch of clamps
A router (a fancy Festool, optional, bits detailed later on)
Guitar building, tradition and technology, by Cumpiano and Natelson. Do not skip this one...
Quartersawn, bookmatched spruce (Tonewood, for the top, AA/AAA grade)
Quartersawn, bookmatched cherry (Tonewood, back and sides, AAA grade)
Ebony (Kauffer, fingerboard and bridge)
White flamed maple (Kauffer, neck)
Various veneers (Had them around, decoration)
Quartersawn splitted spruce logs (Tonewood, bracing)
Some cow bone (Kauffer, nut and saddle)
Tuning machines (Gotoh)
A truss rod (from china, you can make your own easily)
Strings (D'Addario, 2 sets)
Fret wire (Kauffer)
Sandpaper (various grits)
Water-based clear gloss finish (Rothko and Frost, sanding primer + top coat)
Polishing compounds (Rothko and frost)
Yellow wood glue
Different types of tape
Step 2: Sourcing Wood
Viva fui in silvis / Sum dura occisa / Securi dum vixi tacui / Mortua dulce cano
I was alive in the forest / The cruel axe fell me / In life I was silent / In death, I sweetly sing
- Inscription on an Elizabethan lute
I sourced the crucial wood (top, bracing, sides and back from tonewood.ch). An equivalent option can surely be found outside europe, find people who are passionate and to whom you can ask a lot of questions. Don't buy master grade wood for your first guitar unless you are feeling very confident.
At the very least, wood must be quartersawn and exempt of knots. Else, it might structurally fail when put under the tremendous tension of the steel strings.
Step 3: Literature & Plans
Stop playing with matches and go read a book.
- Papa et maman
I used multiple sources from the internet in addition to the book by Cumpiano. While it would be hard to list them all here, here are the most important.
The most valuable resource aside from the book was an open source 1:1 scale plan of an Orchestra Model guitar.
The full-size, high definition pdf of the plan is attached and if you print it at 100% scale you can simply trace it on the wood. It's licensed under creative commons and has been made by the great Mr Grellier, who also provides on his website the CAD files in case you want to modify the plans. A great time we live in. He also has up a lot of pictures of how he made the guitars, which compliment the plans very well and are extremely helpful. Check him out!
Step 4: Cleaning and Setting Up Your Workshop (or Garage...)
Out of clutter, find simplicity.
- Albert "Bébert" Einstein
If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?
- Laurence J. Peter
This is a very straightforward yet important step!
In my experience, cleaning the clutter and setting up proper lighting and a clean work surface makes all the difference between terrible and great work conditions.
You will find the parts you need, work better, tire less quickly and be more accurate in all things.
See the before and after pictures : the only differences are 15 minutes cleaning and about $15 spent on a pine board and a neon light.
Step 5: The Neck Pt.1: the Scarf Joint and Heel Block
The first thing we will do to our neck blank is the crucial scarf joint that defines the angle between the fingerboard and the headpiece. The angle has historically been anywhere from 0° (on some electric guitars) to 90° ! (on some renaissance lutes, for instance)
The joint angle will determine the string tension to a large extent.
The larger the angle, the weaker the joint will be as the gluing surface diminishes. For most contemporary steel-string guitars, the angle most often lies somewhere between 15° and 17°.
This is a point that will come up very often in this ible : This is my first time making a guitar, therefore I will not reinvent the wheel. This means if I don't have a strong technical reason not to do what is usual, I will do as people have been doing even if I don't understand why. The reason why people do things the way they do appears sometimes way later down the road, and i'll keep experimentation for the next guitar!
The angle is measured and cut, then the two gluing sides are planed exactly flat together with the jack plane. The ensures the best gluing for this critical joint. Trueness is checked with a straightedge (or the side of the plane if you're sure it's true). Before gluing, the head plate is thinned with the plane to the right thickness that will accomodate the tuning machines
Next, one face of the heel block is trued with the plane and it is glued onto the neck and will be shaped later.
Step 6: The Neck Pt. 2: Truss Rod Installation
One can easily make a truss rod (see "tools and materials") but I found one for 3 euros on amazon and was happy using that.
A middle line is drawn, along with the final shape of the neck and a truss rod slot is routed by hand with a chisel along the middle line. The truss rod must fit snuggly in there so as not to rattle later on when the guitar is played!
The truss rod slot is routed about 5 mm deeper so that a strip of basswood can be added onto it and the metal does not push directly against the fragile and precise fingerboard.
Note : in the book they said explicitly NOT to try and make the truss rod slot by hand but use a router instead. After having done it by hand, I can tell you they're in the right : my work on this part was passable at best, and the fit is not quite as good as it should be. Use a router if you can!
Step 7: The Neck Pt. 3: Head Veneer and Shaping
I chose some contrasting veneers to sandwich between the neck and the head plate, which is the same cherry as the sides and back.
I cut the head shape on the scroll saw, but ended up changing the design way later on. This can easily be done by hand with a coping saw!
Step 8: The Neck Pt. 4: Tenon and Rough Shaping of the Neck
With a dovetail saw, I cut the rough shape of the shaft of the neck and, very precisely, the tenon which will attach the neck to the body.
The shape of the neck is refined with a drawknife.
Step 9: The Neck Pt.5: Heel Block Carving
This step is purely aesthetic but one of the most enjoyable for me!
The pictures are annotated. First, a primary and secondary facets are established with a plane and chisel respectively, then the shape is refined with a rasp, card scrapers, a kukri knife and finally sandpaper.
I didn't really get creative with the shape but sculpting is really enjoyable as it is quite different form the kind of woodworking I usually do, square angles and all that. This feels almost artistic!
Step 10: Fingerboard
The fingerboard is where the player will spend most of his time.
This one is made out of ebony, which is hard and not sensitive to moisture change, a very determining factor in whether the guitar will keep proper intonation throughout its life.
The spacing of the frets has to be as precise as you can make it. It depends on the length on your scale (the distance between the nut and saddle) and is tabulated. Without going into music theory, it is a separation of the whole musical spectrum of each strings into "pleasing" intervals, defined by Pythagoras back in the old days (pepperidge farm remembers)
Using a scoring knife, I marked the fret intervals then cut the slots with a dovetail saw guided by my best square.
Step 11: Gluing the Fingerboard
Because of it's crucial geometric properties and position compared to the nut, the soundboard must not move during glue-up. It's hard to stress this enough.
In order to ensure this, I first dry-clamped the fingerboard exactly where it was supposed to sit on the neck, that is abutting the nut at a perfect 90° angle.
Then, using a tiiiiny drill bit I drilled two pin holes in the fret slots and used two drill bits of the same size as a perfectly matched pin. You'll get those back don't worry :)
Then I made a clamping caul with chamfered holes in order to accomodate the pins, and glued the fingerboard down with white glue.
Once dry, the pins/drill bits are removed and the fingerboard is shaved down with a drawknife to match the neck width.
Step 12: Jointing and Gluing the Soundboard (and Back)
This is one of the 3 most critical glue joints of the guitar, along with the neck scarf joint, and the bridge joint. If this joint is not perfectly tight, the soundboard could simply break in half under string tension.
First, the two book matched halves of the soundboard have to be jointed together. For this, a so-called "shooting board" was made, in which the two halves are held together flat on a surface and the plane is shot across the side to be jointed while sitting at a 90° angle (see pictures).
Adjust the plane so it takes only a minimal amount of wood out on each pass (see pic) and once you get a continuous shaving along the length, check the two halves together against a source of light such as a window, which will allow you to assess the continuity of the joint. We want no visible light shining through!
Once a good joint is reached, it's time to glue! For this, I made a simple setup in which the two halves are flat on the bench and wedgy cauls are gently hammered from the side to clamp everything together.
Proceed in the same way for the back, then cut on the scroll saw approximately 1 cm or 1/2 inch outside of the outline of your guitar.
Note: Use paper underneath the joint so the soundboard does not get glued to the bench! This is the kind of mistake that generally happens only once ;)
Step 13: Thicknessing the Soundboard, Sides and Back
Now, we need to bring the soundboard and back to an almost final thickness, all the way from the rough lumber dimensions. The wood was about 5 mm thick, and is brought for the sound board at 2.7 mm and 2.4 mm for the back.
There is a lot of different guidelines on what the thickness of the soundboard should be with regard to sound and structure. The main principle, as for many other aspects of guitar building but more so in this step, is that we want to remove as much wood as possible, so that the string vibrations make air vibrate (sound!) rather than the mass of wood (heat!), but not so much that we compromise the structural integrity of the guitar in which the wood is under tremendous stress because of string tension.
Too thick a soundboard will deafen the sound. However, to avoid frustration as this was my first guitar, I erred on the safe side! The next one will be thinner :) Thickness of the back is of lesser importance as it is subject to less stress and not as important for sound.
The thicknessing was all done by hand! Thickness planers are not an option here, as they would destroy such thins pieces of wood. Professionals use drum sanders but I did not have one of those. Eventually, what seemed a daunting task ended up being one of the most reflective aspects of the project. Doing it by hand allowed me to feel the wood in a way that a machine wouldn't and I learned to work a bit more with the wood rather than against it.
Here's how it was done, after one side was sanded down to 180 grit and was facing down on the bench:
(1) Clamp the work piece from the top end.
(2) Diagonally remove material starting from the top left and working your way down
(3) when the clamp is in the way, unclamp the piece, rotate it 180° and clamp it from the bottom
(4) Finish removing material
(5) measure thickness
(6) remove material following the opposite diagonal, repeating steps 1 through 4
(6) measure again!
And repeat all of this until the desired thickness is reached, then smooth the whole thing down following the grain with a card scraper.
Do the back in the same fashion.
Note: Do only one pass at a time! I used a toothed plane blade, which allowed me to see where I had been and not go over that area again, which is crucial to retain homogeneous thickness all over the work piece.
Step 14: The Rosette and Sound Hole (a.k.a Scary Part I)
Alright. This was the first of a couple of nerve-wrecking steps for me, but in hindsight it went juuuust fine and I guess I shouldn't have worried about it that much!
Here we use a router to and 1) remove material from the soundboard in order to accommodate the rosette inlay and 2) make the sound hole
The middle of the sound hole is marked and drilled to fit in a metal pin made from a nail. Then, a new base for the router is made with clear acrylic, in which two holes are drilled in which the pin will fit tightly, and the distance of which to the center of the router bit was calculated so that the router is drawing a circle of exactly our dimensions of interest (see pics!)
I chose some burly veneer for the inlay because I liked the way it looked. Traditionally, mother of pearl is used for acoustic guitars but I wanted the first one to be a very down-to-earth, unpretentious guitar as I had no idea how it would sound. The inlay is cut on the scroll saw and glued in place, highlighted on the side with red and black (ebony) veneer strips.
Then the sound hole is cut out.
Step 15: Bracing the Soundboard (a.k.a the Fun Part)
The voicing of the guitar is where the difference between a wooden box and a musical instrument happens.
- Someone but sadly I don't remember who
The idea is to add bracings to the soundboard so that it becomes stronger. The wood of choice for this is quartersawn, split billets of spruce. Bracing patterns are well established and vary depending on the luthier, the model of guitar, type of strings etc. The braces are glued and material is removed from them with a chisel in what is likely the most defining step (apart from guitar model and wood choice) in what the guitar will sound like.
I am no luthier. This is one of those times in this project where the knowledge is not at all that of the woodworker and belongs to a whole other world, that of musicians and luthiers and I am not in this world. Hence I will say little and refer you to better authorities in this domain. Here's what I can say though:
Again the idea here is to maintain structural integrity with as little wood as possible. However, we are using one more sense here: our hearing! The soundboard is "tapped": hold it with two fingers near the waist and lightly tap with a finger, holding it close to your ear and note the sound it makes.
The tapping is done before bracing, after adding the braces and again as they are thinned down. Before bracing, you should hear a full sound with a lot of harmonics, which will be reduced considerably, especially in the bass side, when the soundboard is braced as it becomes much stiffer and should come back to some extend as the braces are shaved down. Do not shave them down too much, at the risk of mechanical failure!
Again, I erred on the safe side here and left the braces probably much rougher, or bulky, than I could have. But I did NOT want this guitar to break in two when I added the strings ;)
A hard wood bridge patch of 3 mm thickness is also added, which will strengthen the soundboard in the crucial spot where the bridge is glued and string tension is the strongest, and where the bridge pin hole are drilled.
The x-brace (see pics for nomenclature) is reinforced at the joint with strips of fabric soaked in yellow wood glue.
Note: a lot of annotated pics in this step! Look at those for the actual process
Step 16: Bending the Sides (a.k.a Scary Part II)
There are not many pictures of this step as the whole process was both stressful and time-sensitive, but I will walk you through it!
We need to bend the sides in the shape of a guitar.
First, they are thinned down in the same way as the soundboard and back, with the hand plane. Then, they are soaked in 60°C water for 1/2 hour.
The idea is that by applying heat to the moist wood, water vapor will form within the thickness of the wood and make it plastic rather than elastic, which to say that rather than spring back after being deformed it will rather retain the deformation. Then, when cooled down, the wood will remain "stuck" in the shape given to it while it was hot.
My homemade bending iron consists of a soup can and a gas blowpipe.
The wood has to remain wet throughout the bending or it might break or turn to coal. I simply kept dipping the wood in water as I went.
This step was stressful, but incredible. This is as close as you can get to working wood with your own hands, no tools in the way! You actually feel what is happening in the wood, in your hands, and in your nose as you smell the hot aromas come out. The cherry I used, when heated, smelled of hot applesauce and flowers. It was truly incredible.
When you set the wood onto the bending iron and add a bit of pressure, you soon feel it give way under your hands and throughout the process you get a better understanding of when you can bend and when it would break. Start with the wide angles and finish with the waist, which is much more tricky.
After each bend, let the wood cool down in air so it doesn't spring back to its natural flat shape !
The whole process took about 4 hours for me, the time to learn what was happening and how to respond to the various feedback and gain confidence.
The sides are then clamped overnight to dry thoroughly.
Step 17: Bracing the Back
This step is very similar to the bracing of the sound board, not much to say here.
A graft of spruce is added all along the back joint and is chiseled away where the horizontal braces will stand.
Step 18: Fretting
We are going back briefly to the neck in this step, and installing frets!
Fretting is a precise step, in which we have to make sure that all the frets are level, crowned and dressed (flat in regard to each other, and not flat at the top but rather in the shape of a dome) and that they are not presenting any burr on the side that would harm the player's fingers.
The links in this step explain better than I could how to do this process.
My notes are that you should spend a lot of time on this and do it properly. I didn't at first, thinking it was not too big a deal (I wanted to play the guitaaaaaaar), and ended up with a lot of buzzing. I went back to it and did it properly, the difference is incredible in playability and sound. Don't skip this!
Step 19: The Bridge
From an ebony blank, the bridge is drawn and the pin locations as well as saddle slots are precisely marked (use the 1:1 scale plan of the guitar provided above. The pins holes are marked with an awl and drilled and the saddle slot is routed out with a well guided router. Then the shape of the bridge is cut out with saws and chisels and it is sanded to 400 grit.
Note: I didn't guide my router well and the ensuing saddle slot looks... Terrible.
Step 20: Assembly Pt. 1: Soundboard and Sides
Kerfed linings are made from basswood and glued onto the sides, where they will be glued to the soundboard. The sides are then glued to the soundboard, along with the neck mortise and bottom end block.
The kerfed linings are chiseled away to accommodate the bracing of the soundboard, which abuts the sides.
Yes, it's as easy as that :)
Step 21: Trimming the Sides
The back of the guitar is not flat, there is a recline from the waist to the neck.
Using a flexible piece of wood or cardboard, a straight line is drawn from the waist to the neck mortise.Then, the sides are trimmed along that line with a jack plane. This makes a sharp angle at the waist, which is then smoothed using a 120 grits sanding board.
Step 22: Assembly Pt. 2: Closing the Box!
In the same way as the soundboard was assembled to the sides, kerfed basswood lining are added, trimmed to accommodate bracing, and the back is glued to the sides, closing the box. It now looks like a guitar! Almost...
Step 23: Binding and End Graft
Penultimate stressful step ! Messing up here is not dramatic, but it makes a very visible ugly dent in your instrument... Hence the stress!
First the end graft is added, it is simply a trapezoidal piece of wood that goes at the bottom of the guitar. I made room for it with a chisel and hand saw.
The binding is not only aesthetic, it also adds strength to the sound box and protects the guitar should it fall on its side. I chose a simple ebony/maple binding with the black one on the inside to discretely highlight the contour of the guitar.
I made a small attachment to my dremel routing bit, but this can be easily done with any router. Specific bits exist for this task but I wasn't bothered to buy one, as they're quite expensive and serve too specific a task.
Go all around the body on the front and back, then tape and glue the binding strips in place with specific binding tape (it is reinforced with nylon strips so that it does not yield to the binding strips wanting out)
Once dry, the tape is removed and the binding shaved down flush with the body using a hand plane.
Step 24: Final Shaping and Attachment of the Neck
The shape of the neck is refined with a rasp, symmetrically to the marked centerline then smoothed with scrapers and sandpaper.
They say a good rasp gives you super powers and I had no idea how true this was. I found this old rasp of my great great granddad in the garage and man, is that thing a dream to use. It went through the maple like butter and gave such good sensations. The neck is then dry fitted to the box for fun.
Step 25: Finishing
Stewmac has a great guide about nitrocellulose finish. This might be the finish you want to go for if you live in the US, however getting nitrocellulose lacquer is quite difficult and expensive in France, so I went for a cheaper, safer water-based finish instead, which I applied with a paintbrush. I am not very happy with the work I did so I won't give much advice on how to do this part, as there are much better ways of doing it. The truth is, even with all the advice and words of warning against it, I rushed it because I wanted to play the guitar. While this has no real acoustic effects, the finish looks half-assed (which it is) and I will know better for the next one! We sometimes learn from our mistakes, here at Humans Inc. ;)
Here are the links I used!
Step 26: Cat + MMORPG Mandatory Pause While the Finish Dries
Tools required: a cat and a video game to play with your brothers while waiting !
Step 27: Nut and Saddle, Tuning Machines, Strings, Set-up
Well. We are almost there!
Add the nut and saddle, making sure they're a tight fit then add the tuning machines and screw them in place.
Add the strings and tension them a little, marking their place on both the nut and saddle, then remove them and add grooves to the nut and saddle to accommodate the strings. More info on how to set up a guitar can be found here for instance. Again, we step in the world of the instrument maker and I do not pretend to explain this part to anyone as I do not grasp it entirely myself. Here is what I can tell you:
Look forward to the moment your stringed guitar makes a sound. It is a magical one.
Putting the strings on was one of the most stressful experiences of the past year. Damn I didn't want it to break. I was sweaty and swearing and shaking like a leaf in the wind.
Set-up is a big deal. It determines playability, tone, fatigue of the player, buzzing sounds and much more. Today, I'm considering having it done by a professional (costs 50 euros) just to see the difference. Luthiers can tell you how much of determining step it is.
Overall, this project took me from early August 2017 to late February 2018. This is the longest I've been working on one thing, and the outcome was worth every second, every penny, every drop of blood and sore fingers. I am now happy with what I have made, I see the flaws in the final object and can relate them to errors which will be corrected in the next one. I learned a whole lot of new techniques, tools, vocabulary and more general lessons such as patience and humbleness.
First Prize in the