Converting an Acoustic Guitar to a Fretless Guitar

Introduction

It’s been about 12 years since I wrote “Converting an electric guitar to a Fretless Guitar” for Unfretted and an update is long overdue. Removing frets and filling the slots with epoxy is a cheap and easy method, but it does have its drawbacks:

Since epoxy is a viscous liquid, it’s hard to get it to flow into the thin fret slots and fill them completely. Sometimes it just rests on a slot without flowing in, which you discover after sanding and realize you’re not quite done yet. Though this might have been an incompetence on my part.

Another issue is that, epoxy appears to be harder than ebony. Which means, it doesn’t wear at the same rate, so even if you get the fingerboard perfectly smooth at the beginning, you might end up with the fret slots being higher after a while and it might cause buzzing. If you were to play it long enough (100 years?), it might become a fretted guitar again!

After 12 years of playing and virtually no maintenance, the fingerboard on my “Vic” (the guitar from my previous tutorial) was looking like this (I only remembered to make a photo of it after detaching it from the guitar).

Vic Fingerboard

See how the strings have dug into the board (even though I only play flatwound strings) and how the epoxy fillings don’t look that good anymore. I also had this weird issue of inlay dots slowly sinking into the wood, refusing to be level with the rest. They aren’t in the way of the strings, but still…

So, instead of trying to repair it, I decided to replace the fingerboard with an ebony blank. I thought about getting the job done by a luthier and be done with it. I contacted a local luthier and also checked prices online, only to find out that it is rather expensive to have it done by an expert. I had to do it myself…

I used to think that it would be a real hassle to get the old fingerboard off the neck, since it appears to be permanently attached with glue. Yet it turns out, this glue can easily be softened with heat, just like the glue that holds frets in place.

Having solved half the problem, I then searched online about where I could order a custom-cut ebony fingerboard that would fit my guitar (because I don’t have the necessary woodworking equipment to cut it myself). Any guitar or violin maker should be able to do it, it’s just a matter of finding someone who does it more affordably. I found a luthier here in Germany, who sells custom-cut ebony fingerboards for around 50 Euros, so I was set.

I first successfully replaced the fingerboard on my electric “Vic”.

But then I couldn’t stop there. See; since my first ever fretless conversion, I had in mind to convert a steel-string acoustic to unfretted, but years went by and I never got around to it.

Until now.

So this tutorial will document the fingerboard replacement procedure on an acoustic guitar.

The Guitar

My victim is a 40-year-old Klira “Blue Hill”, made in Germany in either August 1977 or July 78 (I assume, because of the number “778” on the label), which I bought for only 85 Euros.

Klira Aoustic

It has three characteristics that are a bit unusual for acoustic guitars:
– It’s got a bolt-on neck.
– It has a somewhat arched back.
– It also features an adjustable bridge, which lets you adjust action with just two screws.

Klira back

I thought the last one would be an advantage for fretless, allowing one to dial in the ideal string height easily, but it actually doesn’t go low enough for fretless. It also turned out to be a disadvantage with regard to sound: it adds a lot of mass to the bridge, at exactly the point where it matters the most, effectively damping the vibrations and influencing volume, sustain and tone in a negative way. If you’ve ever seen a violin-mute, you know what I mean; they’re basically weights attached to the bridge in order to bring the volume down for home practice (while killing the tone). The problem with this bridge isn’t just excessive mass though; the saddle itself is lifted away from the bridge by the adjustment screws as well, so the vibrations from the strings reach the body only through these two screws instead of the whole saddle surface. Plus, the saddle itself is made of some kind of soft plastic, which further dampens the sound.

Some further reading about reducing bridge weight:
frets.com/FretsPages/Luthier/Technique/Guitar/Bridges/HumBirdBr/hbirdbr1.html
(funny linking to a page called “frets” on unfretted)

In my case, the whole bridge weighs 112 grams, about double the weight the guy at the link wasn’t happy with. I’ll see what I can do about it.

The guitar, in its stock state, with its old strings, worn frets and unnecessarily high action, is pretty hard to play and the tone is rather dark and midrange-heavy. The top plate appears to be made of solid wood instead of plywood, so it should sound pretty good once I do something about the bridge.

This is the documentation of how I did things, rather than a real tutorial by an experienced luthier that shows how things should be done. It may not be the best method, but I’m sharing it with the hope that it might help somebody. Proceed at your own risk. I’m not responsible if you break something!

Here We Go

The first step was to measure the old fretboard and order an ebony fingerboard at that size. It likely won’t measure in exact millimeters, so I think it’s a good idea to have the fingerboard cut a little larger rather than a little smaller. You should sand the fingerboard to fit the neck, instead of the other way around. Because if you were to sand the neck, you would be removing the varnish on it.

I ordered my fingerboard from Dreier guitars in Germany, and it cost me about 50 Euros. If you have access to woodworking equipment, you may be able to do it all by yourself, which would be cheaper. Ebony by itself is usually not very cheap though.

My new fingerboard looks like this.

Ebony fingerboard

I didn’t care about it being uniform black, and I asked the luthier to pick a piece of ebony that doesn’t have large pores so it wouldn’t cause buzzing problems.

Now, I’ve got to remove the old one. I began by detaching the neck from the guitar.

detaching neck

If you’re working on an electric guitar, leaving the body attached might be a good idea. Because you can then clamp the body tightly to a table and work on the neck. I didn’t want to clamp down the hollow body with its thin top and bottom plates. Besides, the back on this guitar is arched, so it wouldn’t have worked well anyway. With the body out of the way, I have to clamp the neck itself on the table, and the clamp will get in the way as I work, but it should still be doable.

Removing the nut

You need to remove the nut before you begin. It usually separates easily when you tap it lightly with a screwdriver and hammer. It didn’t separate that easily on my guitar and broke. But this was a cheap plastic nut, and I wasn’t going to use it anyway. I want to make an ebony nut for this guitar. More on that later.

Nut removal

Removing the fingerboard

To separate the fretboard, you need a clothes iron and a tool with a thin but stiff blade, something like a putty knife or a spatula. It shouldn’t have sharp edges like a regular knife though, as there’s a risk of cutting into the neck if the tool is too sharp. As for the clothes iron, I have one without the steam feature. If you have one with steam, it might be a good idea to turn it off, to keep the wood dry. If, however, the glue turns out to be stubborn, you might need to resort to steam to get it to let go. But try it dry first.

Before you begin, there’s the question of whether to leave the frets on, or to remove them first. Both options might have their advantages: if you leave the frets on, they might help transfer the heat better to the bottom of the fretboard (where the glue resides). But without the frets in the way, the clothes iron would be able to heat a whole area, instead of just thin strips. I’ve tried both, and I think the process might be a bit easier without frets. But since it would require extra effort and time to remove the frets, I’ll just leave them on.

The procedure itself consists of heating a small area with the iron, and then acting quick to separate that area with your spatula before the glue cools down. There are few video tutorials at youtube which you can watch.

Set the iron to its maximum temperature and place it on the fretboard at the nut end.

Ironing the fingerboard

Let it first warm up for 5-10 minutes. I’m using a cotton cloth between the iron and fretboard. It’s not to protect the fretboard (which I have no further use for); it is to keep the bottom of the iron clean (so your shirts won’t get brown stains while ironing). If you do use a cloth, make sure it’s 100% cotton, as synthetic fabrics will probably stick to the iron at that temperature.

You start at the nut end with your spatula and slowly make your way towards the other end. Slow is the key word here. Each time you heat an area, you’ll first be able to separate easily, but after a minute or so the glue will cool down again and it will get harder to progress further. At that point you should place the iron on the fretboard again, heat for a couple of minutes, and then continue.

Separating the fingerboard

You can measure your progress with the frets. At the beginning you might separate maybe half a fret at a time, before you need to put the iron on and heat again. But as you make progress and as the frets become smaller, you’ll be progressing 2-3 frets at a time, and towards the end it might be 5-6. You have to be patient and try not to rush. If you’re not dealing with an especially stubborn and uncooperative glue, the whole thing should take about half an hour, maybe less.

More separating

What also helps is rotating the tool left and right (horizontally; clockwise and counterclockwise) instead of trying to just push it forward. Try not to wiggle it vertically too much, as there’s the risk of either the fretboard breaking at one of the frets (as the wood is much thinner at those points) or the tool cutting into the neck. It wouldn’t be a huge problem even if you break the fretboard, since you’ll be replacing it anyway. Just try not to harm the neck itself.

and more separating

And here it is, fully and cleanly separated.

Fingerboard off

 

Fitting the new fingerboard

Now, to gluing on the new fingerboard. This is actually a straightforward process, but there are a few tips which might help you do it better.

The glue is important. You can theoretically use any kind of wood glue or even epoxy. However, you might need to remove the fingerboard again sometime in the future. And having already experienced that it’s not really that fun to separate it, you may want to make sure to use the right kind of glue, so it can be removed without your future-self cursing you. And the consensus seems to be that “Titebond Classic” is the right glue for this job. There are also other kinds of Titebond, so make sure to get the classic version.

If you were to simply spread glue and clamp the fingerboard down, chances are the fingerboard will keep sliding around under the clamping pressure. A trick I learned from watching luthier tutorials is to use two tiny nails on the neck and have notches in the corresponding positions on the fingerboard, so you can push it down and lock it in place like a lego brick.

To do this, you need two very thin and short nails or metal rods, which you hammer in at the both ends of the neck, leaving just a tiny bit sticking out, maybe like half a millimeter. If you use nails, cut off the flat end (and shorten them, if too long) using pliers.

pins

You then place the new fingerboard over the neck, align it correctly and press it down firmly with your palms, so that the nails leave indentatitons/marks on the back side of the fingerboard. Now you can drill tiny notches at these marked points. Ideally, the drill bit should have about the same diameter as the nails you use. I’m using a dremel-like rotary tool.

drilling ebony

Ebony is one of the hardest woods, yet it feels like butter when using a high speed rotary tool with a tiny drill bit. So you have to be really careful not to drill all the way through the wood. Just a small notch, less than a millimeter deep, so that the nails can hold on and prevent the fingerboard from moving around.

Checking neck

Then, before applying glue, first try putting the board on to make sure that it locks properly in the correct position.

Another luthier advice is to cover the truss-rod channel with masking tape before spreading the glue, so you don’t fill this channel with glue. On this particular neck, most of the truss rod channel has already been filled with wood, but on many guitars there’s usually a long and continuous channel along the neck.

Applying glue

Use plenty of glue, spread it well, and then remove the masking tape.

Removing masking tape

Place and lock the fingerboard in its place.

Position the fingerboard

Then clamp it down.

clamping

It’s a good idea to use as many clamps as possible. I’m using 5, because I have 5. If you have more, use them. I’ve also placed a piece of flat wood between the clamps and the fingerboard, which I’m thinking should spread the clamping pressure over a greater area and also should prevent the clamps from digging into the precious fingerboard surface.

Right after clamping, glue will begin to squeeze out from the sides. Wipe clean with a damp cloth/paper towel. Keep an eye on it for the next hour or so, just in case more glue comes out, so that you can wipe it before it dries.

Then let it dry overnight.

You’ll probably need to sand the sides a bit get the fingerboard flush with the neck, in order to accomplish a perfect transition between the two. It takes a long time to sand ebony down, so if there’s plenty of material to remove, you can use a wood file first and continue with sandpaper later. Just be careful not to scratch the varnish on the neck with the file.

After sanding, it looks like this.

Neck completed

Now you should decide whether you want your fingerboard to have a radius or leave it flat. If you do want a radius, you need to get a radius sanding block and sand the fingerboard. On my electric guitar I used a 20″ radius block for a subtle curve. However I will leave this particular one flat. My fretless classical guitar also has a flat glass fingerboard and I find it perfectly playable. Besides, the new fingerboard already has a machine-planed and perfectly flat surface, so I won’t try to fix it if it isn’t broken. But it might become curved after being glued to the neck, and I might have to sand it after all. We’ll see.

Lowering the action

The next step is to lower the action (string height) to make the guitar playable and to get better tone and sustain. You can take a look at the other tutorials on unfretted on how to do that. You basically need to get both the nut and the bridge lower. The nut will have to be sanded down to correct height – the usual advice is that the strings should be so low on the nut end that you can barely insert a piece of paper between the strings and the fingerboard.

When converting an electric guitar, the bridge can usually be easily lowered by means of adjustment screws. On an acoustic, however, you also need to sand the saddle down. You should also make sure to adjust the truss rod to get the neck as flat as possible. If the neck is perfectly flat, you can get the action really low and have a warm fretless tone with plenty of sustain.

Working on the bridge

As I previously mentioned, this particular guitar had an unusual bridge. And while it did look somewhat “cool”, there was simply too much weight on the bridge, killing the sustain and the tone. So I tried to make it as simple and light as possible by removing all the unnecessary metal parts. Originally, the bridge was not glued, but screwed on to a metal plate which rested inside the guitar. There was also the aforementioned action adjustment mechanism that added more weight.

I got rid of all the metal parts and simply glued the bridge to the top plate (using again Titebond for glue, in case I need to remove it in the future).

These are the pieces that are left out.

Bridge pieces

In order to get the action low enough, I had to carve channels for the strings in the bridge. I threw away the soft plastic saddle and cut a new saddle out of bone blank, which gives a brighter tone and more sustain. The whole bridge now weighs about 60 grams lighter – which is a 50% reduction!

The bridge with the bone saddle now looks like this.

Bridge with bone saddle

 

Working on the nut

As for the nut; the idea was to make it out of the same material as the fingerboard, so that open strings don’t sound hugely different from the fingered notes. I found out that you can buy small pieces of “leftover” ebony on ebay for a few bucks. I got one and cut a nut out of it. I found out the hard way that ebony can be somewhat fragile if you’re not careful with it. It’s not fun to spend an hour shaping a nut from scratch, only to have it snap in half while installing the strings. But it did work out in the end.

Here’s the finished nut next to the piece I bought.

Nut and ebony blank

I also decided to remove the plastic pickguard since I don’t usually play with picks anyway. It was screwed on, so the screw holes are still there, which I might later fill with wood dust & glue. But it doesn’t bother me that much.

The finished acoustic fretless guitar

The final touch was installing new strings. I’ve currently got a set of D’Addario EFT13 Flat Tops (016-056) on it. These are roundwounds that have been ground to a smooth surface. They sound a bit brighter than regular flatwounds. So far, I’m happy with the tone. Though I might try regular flatwounds at some point.

Here’s the fretless “Klira”!

Emre Meydan
2018

Links

Converting an electric guitar to a Fretless Guitar

How to set up a Fretless Guitar

More Do-It-Yourself projects

 

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