Monday 21 December 2020

Building a 13 Course Lute, Start to Finish, 24: Frets, Strings and Sound

Hello my friends!--and welcome back to the final episode of the series wherein I show how I go about building a 13 course lute, with a body based on the archlute by Magno Tieffenbrucher, C45 in the Vienna KHM, and a peg box and bass rider arrangement based on the lute by Sebastian Schelle, E.633 C.218 in the Cité de la Musique, Paris. As always, I have much to show you today, and I'm afraid it will be a long post. I'll try to be gentle; and I thank you, in advance, for your kind attention. 

Here comes the firehose.

Tying the frets

There are lots of good descriptions all over the internet of how to tie lute frets, but here's my version. I personally think the best description out there, which appears to be quite straightforward and give a good result, is Martin Shepherd's. (The video's here.) I haven't tried it yet, but I will soon. In Martin's version the knot comes around the neck in the opposite direction to mine. My advice: try 'em both, see which one you like best.

The tools and materials of the trade: a selection of fret diameters (from 1.4mm to 0.60mm, graduated by 0.05mm), a pair of pliers, a butane lighter, fingernail clippers, and a wood-burning tool.

Neck's all ready. Fret me!


I don't use the pliers to pull frets tight--I only use them to crimp about an inch of the end of the fret, so that it's easier to tie the knot. (This is especially useful on larger-gauge frets, which can be quite stiff and hard to bend.)

Then I burn the tip of the crimped end.

And tie an overhand knot in that end. 

I pass that knotted end under the neck so that the knot emerges on the bass side. Then I slip the free end through the knot.

I brace the fret with the left thumb, and pull the free end back toward me so that the fret tightens.

I bring in the pinch-clippers to cut the end off, leaving a few millimetres...

And scorch the free end with the wood-burning iron. I like using this tool for this part of the job because I prefer to keep open flames away from the instrument, especially if there are strings on it. This one hasn't been strung yet, but when it is, it will have bass courses overhanging the edge of the neck.

The finished knot.


Because it can make a groove and mar the neck as I pull the fret into place, I put a small slip of card under the knot. The problem is more acute in a pear neck than in one veneered with ebony, but I do it anyway, just in case. 

I brace the instrument carefully while pulling the fret down into place.

I've made a card marked with the (provisional) fret positions and their diameters. The end of this card rests against the front of the nut.

There's the fret in place. This baroque lute has 10 tied frets, and the 10th ties easily. I don't care much for having to notch the edge of the fingerboard to keep a fret in place, or to hang the fret on a button drilled into the middle rib. It's much easier and better just to pay attention to this detail in the lute's design stage, and ensure that the fret has room to stay where it's tied.

The compleat set. The frets are graduated along the neck's length. The largest, nearest the nut, has a diameter of 1.10mm.

Okay, moving on: let's get some strings on this fellow.

Stringing up

I start with the strings to the main nut. First, I lay out the position of the string grooves. 

When I shaped the nut (in the previous episode), I kept the treble edge square, for just this purpose: to match my card against it, and accurately mark the string locations.

In each of the string marks, I make a preparatory cut with an x-acto blade. I've run this blade over a fine file, which slightly serrates the edge and turns it into a kind of small saw blade. Each little kerf makes a secure place to seat a small tapered file, which ensures that string groove will be in exactly the spot I want it to be. 

All of the string grooves will be filed in situ on the lute, so I string one bass string in order to hold the nut in place while I work. (I haven't yet filed a groove for this string.)

My tools of the trade for this job: two fine Grobet files (#4 and #6), a selection of graded spacers, a tube of metal polish, and a length of fine cotton yarn.

I begin with the first course, seating my #4 file in the saw kerf, and making a fine, evenly-shaped groove. I don't file too deep: I only want to create a groove in which I can place my first course string, wind it on the peg, and check its height.
I very lightly file the leading edge of the groove--not so much that it will create a buzzing, sitar-like effect; only enough to remove any sharp edges that can abrade the string.

I file the groove lightly with the finer #6 file, and then polish the groove with the cotton yarn charged with a little of the metal polish. 

I then wind the string, and slip my spacer piece under it, beside the first fret, to check its height. 

This already looks pretty close: for the first course, I want a height of around 0.45 or 0.5 above the fret. Since the fret is 1.1 mm in diameter, that means I want the bottom of the string to be about 1.55 or 1.6 above the fingerboard. As you can see in this photo, there seems to be a tiny bit of space between the bottom of the string and the spacer. I think I'll file with the #6 file a bit more, then polish with the string, then check the string height again. 

Using side lighting can sometimes show more easily how much clearance there is between the bottom of the string and the top of the spacer.
I've found that the best way to use this system for setting string heights is to file carefully, then polish, then check string height, and then repeat this sequence as necessary until the correct height is reached. I always have a final height in mind for each course (and that height increases slightly for each course as I move across the string band from the treble to the bass side.) The best way to ensure that I don't go too far is to use a spacer that is 0.05 mm higher than the final height I want. When I slip the spacer under the string and it nudges the string ever so slightly, that's when I know I have achieved the correct string height, and I can move on to the next course.

I usually wind the courses that I'm working on, and just keep them to the side of the grooves, so I can see how thick the string is and use the segment of the tapered file that best matches that diameter. I also broaden the groove (by using a wider part of the file) as the string goes around the curve on the back of the nut. What I'm doing there is actually easing the curve, making it slightly less sharp. 

When I'm working well--when I'm getting into the groove, so to speak--I can do a double course of strings in about 15 minutes. That means I will finish making the grooves for the first 11 courses of this lute in a little under 3 hours. Not too bad, for what might at first blush appear a bit of an overwhelming task.


By the way, to wind the string onto the peg in the chanterelle tuner, I thread the string through the hole in the peg, then bring it around the back side of the hole and thread it through again. For the rest of the strings in the main peg box, I thread the string through and then loop it around and under, so that the free end of the string points away from the near peg box cheek--like so:




Stringing the two lowest courses in the bass rider is pretty straightforward--I mark the positions, use the x-acto knife/saw, then file some grooves. I don't have to worry about how deep to make the grooves so that the string is a certain height...

... but I do have to make sure the grooves are deep enough, and the outer ones curled in a little, so that the strings won't slip out of their grooves when they're brought up to tension.

At last--the lute is strung. 

Now, all I need to do is start tuning--and keep tuning, and then tune some more, for days on end, until the instrument starts to settle into an equilibrium. The strings need to stretch, and the lute needs to flex slightly to accommodate the tension that's suddenly been introduced. The belly under the bridge may rise slightly, the neck may pull forward, and the action will likely rise by a couple of tenths of a millimetre. I expect all of these things to happen, and as I tune and play I keep an eye on how all these factors work together. Throughout this process, I also get my first real idea of how this lute is going to sound--and that's a thrilling, as well as a somewhat daunting, prospect. As with every lute I make, I've not only put a lot of work into this instrument, but more, I've put every ounce of knowledge, experience, intuition and musicality. I want the lute to sound beautiful--but will it? How can I know? Will it have strength, volume, projection? Will it have subtlety and soul? Will there be an evenness of response across the string band? Will it give everything the player asks of it? Will the treble sing? Will the sound of the basses break your heart?

Only time will show these things, and it won't necessarily show them to me. In my workshop, I'll only get the merest glimpse of what this lute might sound like. Very soon I'll be giving it up to the new owner, who will be the one responsible for bringing it to life and giving it its true voice. My job, at this point, is to make sure that everything works--the strings vibrate without buzzing at the nut, the pegs are well fitted and lubricated, and the feel of the lute is friendly and comfortable. At this point, lute making is a matter of details; it were ever thus, but at this point even more so. So let us put the finishing touches.

Body Frets

Now that the lute's finally well in tune, I can find the octave, calculate the correct placement of the frets, and nudge the tied ones into place and make and accurately glue the wooden body frets. 


To find the octave, I use a small piece of body fret shaped from a strip of ebony. I move it slightly up and down the string until I find the exact spot where the fretted note matches the harmonic at the mid-point of the string. (I could do that by ear, but for convenience's sake I use an electronic tuner.)


While holding the fret down, I make two light marks with a sharp, soft lead on each side. Then I lift the fret away and mark the mid-point. That mark is my octave.
I can then measure the distance between that mark and the front edge of the nut, and double the number to give me the playing string length of the lute. This string length will be a little shorter than the physical measurement of the string from the bridge to the nut--usually a few tenths of a millimetre--owing to the physics of a string that's been stretched in order to be pressed down onto a fret. Once I have the playing string length, I can use it to calculate the accurate position of all the frets. I mark these positions on a strip of card, lay it down on the fingerboard beside the first course, and push or pull the tied frets into their spots.

The 11th and 12th frets, however, I'll need to locate and glue down accurately on the belly. Here's how that process goes.

I want the ends of the body frets to basically follow the line of the treble edge of the fingerboard, so I lay down a short strip of masking tape on the belly that projects this line. I then mark the positions of the 11th and 12th frets on the edge of that piece of tape.
At each of these points, I lay down my small rule and measure how long the fret should be. I want the 11th fret to cover the first four courses, so I measure from the mid-point between the fifth and fourth course, to the edge of the masking tape. As shown, the 11th fret should be about 38.5mm long.

The 12th fret will cover the first three courses, and so will be 29.5mm long.

The last tied fret, the 10th, has a diameter of 0.80mm. The next fret in line, the 11th, can be a little taller, since the level of the belly begins to fall away slightly from the body neck joint. I'll make the 11th fret 0.95mm tall, and the 12th fret 1.05.

Here are my fret blanks--strips of ebony and hard boxwood. I usually leave it up to my clients to decide which they would prefer, and for this lute, it will be ebony. I use my pull-through scraper (the same one I used to size up spacers for the back--detailed in episode 1 of this series) to make strips of fret material exactly 1.5mm wide, and of various, accurately measured heights. 

I cut the fret material a little over-long, and then shape it pretty carefully with a fine file.

I hold it in a ledge jig to file a smooth quarter round on one end...

...and then the other; then I flip it around to file the other edge. 



I cut the fret to the exact length, then dock the ends with a 45° stroke with a file.

There they are: the shaped frets.
I have a pretty slick routine for gluing the frets in place, which I'll show you now. Sadly it involves, first, de-tuning the lute and slacking all the strings to move them out of the way. That's all right though--it allows me to do a couple of other small jobs that are crucial to the smooth functioning of the finished lute.  I'll get to them in a minute.

First, as you saw above, I marked the position of each fret on a piece of masking tape. That mark shows where the treble end of the fret lies; now that I've got the frets made I can lay them down, in position, and stick another small piece of tape beside the bass end of the fret. I then mark the fret position on that tape too, and draw a line with a sharp, soft pencil, on the belly between those two marks.

Then I scrape away that line, and along with it, a bit of the finish that I put on the belly in episode 18, to expose a bit of fresh wood for gluing.


I don't scrape away too much--just enough that the body fret will glue securely.

Hot hide glue is my choice for this job. First, a quick, light coating on the bottom... 

...and I get it stuck in place quickly, and hold both ends down while the glue sets a little.

Then my steel rule provides clamping pressure for a minute or two.

And that's basically it. When I have both frets glued in place, I wait a few minutes, then brush a drop or two of water over them to soften the bit of glue that's squeezed out. Then I can come along with a sharpened spruce stick and clean up the excess. It leaves a very nice result, I think.

Now while this glue is firming up, there are a couple of other finishing jobs to do.

Fitting the strap button

One of the last jobs I did before gluing in the belly (in episode 13) was to drill a pilot hole for the strap button. Now, I'll enlarge and taper that hole with a reamer (the same small reamer I used to fit pegs in episode 23.)
I make strap buttons out of many different woods--pear, plum, boxwood, snakewood, holly. I usually turn a bunch every few years when I have the lathe out to make sets of pegs. The black strap buttons you see in the photo above are not ebony, but instead are boxwood, a softer material that I dye black and oil.

I shape the shank of the button with a flat file, looking to match the taper of the hole. 

When I've filed the correct taper in the button, then fitting is simply a matter of reaming the hole to the proper size.

I generally don't glue the strap button; if it ever needs replacing, it's a pain to get a glued one out. If the button's well fitted, there should be no problem with it slipping out of its place during use.

A few final tasks

Now is the time, while the strings are off, to give both nuts a final shape and polishing.

One priority here is to round over any sharp corners on the nuts that could injure the player. This is mostly a problem on the treble edge of the main nut. Up to this point, that edge of the nut has been left square, but now it should be rounded generously on the top, front and back edges (and even the underside can be gently relieved.)


At the same time, it can be a good idea to re-shape the top of the nut if the string grooves are excessively deep (they should be no deeper than half the diameter of the string, and some players prefer they be much less than that), or if there is excess material on the upper part of the back edge--where the strings should glide easily over a gentle quarter-round profile.


A final touch is to give the top and back of the nut, as well as the string grooves, a final shine with a little metal polish squeezed onto a fine-grit sanding block.


After the big surfaces are polished, I also give the string grooves a final touch with the cotton yarn. Then I clean up all the excess with a soft cloth.

 
Both nuts are polished, and almost ready to receive strings again. But first...




I'll take the opportunity to lube the pegs one last time with soap. This is an operation that needs to be done frequently in the first few months of the lute's life; if it isn't, the pegs can become sticky and very cranky to use. (I'll include a small piece of dry hand soap in the case for the new owner.) After a while, they become well enough lubricated that they might in fact need to have a little chalk rubbed on the contact surface to make them stick properly--and I have included a piece of chalk in the case for that purpose, as well.
Now I can re-load all the strings in the peg boxes. For the main peg box, instead of starting with the first and stringing in sequence to the 11th, I wind the strings from both outsides in--that is, from the 1st course to the 6th on the treble side, and from the 11th course to the 7th on the bass side. This keeps the strings orderly and prevents them crossing in the peg box.

I think that's it. I think this 13 course lute is now finally truly finished, and ready to leave the workshop.

I have one more task to complete, and it really has nothing to do with work on the lute itself. It's to make some sort of record of the lute, as it sounded on the day that Bob, my client, drove to my workshop and picked up his new lute. I felt that it might be a good thing to include in this blog a sound sample of this thing that's taken up some months of my working life to build, and many more months of my life to write about. 

Bob picked up his lute in the spring of 2020. At that time, the city of Vancouver (and the province of British Columbia) had been in a state of lockdown for some weeks, due to the outbreak of Covid-19. I held onto the lute while both of us waited for a break in travel restrictions, so that he could make the 5 hour drive into Vancouver to pick it up. I kept the lute in tune, and resolved to play it as much as I could while I had it; but I'm not a baroque lute player, and I had a new 7 course lute of my own which I had finished alongside the 13 course (I'll tell you about in a future blog post), and that was taking up most of my playing time. So, the 13 course was languishing... a little.

One day, Bob decided he had waited long enough, and that the coast was clear for him and his daughter to make the trip. They got in Bob's truck; they drove; they picked up the lute; they drove home. The operation went very smoothly, Bob had his lute, and potential Covid exposures were kept to an absolute minimum.

Bob had told me that they were leaving early, and hoped to be in Vancouver, at my workshop, by 1pm. I brought the lute with me to the shop that day, and waited. Around 12:30 I sat down with my phone camera to make an audio-visual record of the sound of the lute; I turned on the phone and started recording, just goofing around, doing what I thought was a dry run. I shut the phone off, and was getting ready for the real thing, the real "take one"--when there came a knock at the door. It was Bob and his daughter. I put the lute in its case, and handed it over. I never got a chance to do the real "take one."

And so, in the place of a real recording of the lute, I offer you this--three rather informal minutes or so of me making sounds with this 13 course lute. It's not a pristine recording, and I'm not much of a baroque lute player, but there it is--perhaps it will give you an idea of how this lute turned out. 

My series is done. Thank you for reading, commenting, listening. I wish you all a happy and healthy holiday and new year--and I hope to talk to you all again soon.