Tuesday 22 September 2020

Building a 13 Course Lute, Start to Finish, 22: Dyeing the Peg Box, Finishing Out, Oiling the Neck and Peg Box

Hi friends, it's been a while, and I hope you're well. I'm itching to get back to the story of the 13 course lute in progress. Let me catch you up.

Last time we spoke I showed you how I put together the peg box of this 13 course lute: building the box and veneering it, fitting and carving the chanterelle tuner and bass rider, and finally making the joint and fitting and gluing to the neck. A very satisfying process, and it all went quite well.

Now I've got a few more jobs to do before I can finish out the neck and peg box and apply a finish. I'll tell you about these jobs today.

First, a look at the glued-up peg box. You can see here how much wider it is than the neck in this Schelle-style arrangement--about 10mm. (The way I think about the width of the peg box is that the inside of the bass side peg box cheek more-or-less coincides with the bass edge of the fingerboard.) The exposed extra width needs covering up: as in the original Schelle lute in Paris, I fit a thick piece of ebony onto the top of the box and against the edge of the neck and fingerboard.

The grain of the insert piece is parallel to the grain of the fingerboard.

Here's my fit. This will be fine, but I think I could have saved myself a bit of trouble in the fitting if I had left the edge of the fingerboard square (that is, not rounded over) in just this area.

Once it's glued in place, I can shape and trim the piece. A skew chisel seemed the best tool for this job (I think the position of the bass rider made it impossible to use the low angle block plane.) Please note that my left index finger is positioned well down the front of the peg box; if my chisel happens to slip, my finger is not going to be in the way of the cutting edge. Another item to note, as far as technique is concerned, is that I am holding the chisel close to the cutting edge for good control, and that my right hand orients the tool, while my left thumb applies the cutting force. 

I use the same tool and techniques to trim the outer edge of the piece.

And though this looks a bit unlikely, it was the best position I could find for filing flush the back side of the piece. My left elbow rests upon the bench; the lute is well-braced against my shoulder and side of my neck, and against the two cork blocks on the bench.

There's my result. As you see, on the upper surface the piece is shaped as a continuation of the fingerboard's curve.

On to the next chore: I want to do a little more carving of the bottom block to get a good final shape, and remove some glue residue left from when I stuck the peg box on. (Again, the right hand holds the tool, the left thumb applies the force.)

Now it is time to dye certain parts of the peg box black. As on the original Paris Schelle, I will black only the bass rider and chanterelle tuner; I'll also dye the little tongue of neck wood between the peg box and the fingerboard. The inside of the peg box, as well as the peg box cheeks, will be left their natural colour. 

This process involves carefully masking off the peg box cheeks. Though I will try to be as careful as possible when I apply the dye--especially where the dyed and undyed sections meet--I also want to make sure that the edge of the masking tape is pressed down very well to prevent colour bleeding. 

This is my dyestuff: powdered logwood.

I measure a small amount into a jar that's about half-filled with distilled water. 

The mordant: ferrous sulphate. I measure a similar amount into another jar half filled with distilled water, and then place both in a water bath, and heat, almost to the boiling point.

Here is the set-up. The cloth over the belly helps to stabilize the lute, but it's mainly there to prevent any bits of dye from getting on the belly. I try to be very careful brushing dye and mordant, but a little flick of a bristle could send a tiny drop flying, with potentially heart-sinking consequences. 

This is what the logwood looks like going on first: it shows not black  but red or yellow instead.

The mordant fixes and colours the dye--you can see it becoming black where I've brushed it on. The coverage is a bit motley at first, but by the time I do a number of alternate coats (dye-mordant-dye-mordant-dye, with a few minutes' drying time between), the colour evens out nicely.

When the dyeing is done, I leave things to dry overnight and then next morning carefully wash the dyed areas with cold water and a toothbrush, to remove any traces of free dyestuff. 

I didn't take any photos of the finished dye job specifically, but you will see the result just a little farther along in this post, when I apply a finish to the neck and peg box. For now, I want to move along to the next job: giving the fingerboard a final shape, and setting the final action.

You might remember my description of the tedium of shaping the fingerboard when I originally did it, in episode 16 of this series. At that time--just before finishing out and varnishing the body--I left the lute's action about 0.1mm higher (measured at the 8th fret) than I want the action ultimately to be. This was to help account for any possible movement of wood and consequent change in the lute's action during the varnishing process. Even under normal circumstances wood never really stops moving and changing shape, but there are a couple of reasons to be wary of it during this time: first, the fingerboard had been glued on only fairly recently, and might still have been settling into its final shape; and second, the UV booth I use to cure the varnish--in which the lute is kept for around two solid weeks--is a fairly warm and fairly low-humidity environment. Both of these circumstances call for caution in shaping the fingerboard and setting the action. It's a lot easier to leave the action provisionally high a very small amount and then lower it later, than it is to try to find room to raise the action if, as often happens, the lute comes out of the light box with a slightly lower action than when it went in.

In any case, I always find it a good precaution to leave the lute for as long as possible before working on it after taking it out of the light box (or indeed after a major gluing job such as the fingerboard), just to let it settle into shape in the ambient humidity of the workshop (40-45% r.h.) The process of cutting the rebate for the peg box, then making and fitting the chanterelle tuner and bass rider, gluing up, and dyeing, takes I would say at least a week; and that's enough time for things to have settled reasonably well, and for me to move on to the final shaping work.

I mask off the entire belly against ebony dust. I lay down masking tape across the 'belly tongue,' then cover the rest with paper towel.

A cutout for the bridge allows me to string nylon fishing line on the first eight courses, and the 12th course. 

I string lines only on the top eight because those are the only courses that are fingered (with rare exceptions, I am told) in the baroque lute's repertoire. It's not that the rest of the courses that cross the fingerboard are ignored--I will be keeping a close eye on the longitudinal flatness of the fingerboard under those courses--but I am not so concerned to know their specific stringheights. (I string the 12th course, by the way, because I want to see how the things are going to line up on the bass rider.) 

If you've looked at episode 16, then you'll already be familiar with this drill. Stretch the fishing line over a 1.6mm thick spacer at the first fret, then measure the height of the string above the fingerboard at the 8th fret with a spacer of appropriate thickness.
I've made a set of these carefully-thicknessed spacer pieces just for the purpose. I find that having them a few centimetres long, rather than short blocks, makes them much easier to use, especially on the curved fingerboard of the baroque lute. 

Here's how I keep an eye on the flatness of the fingerboard: draw an array of lines exactly under each of the courses; set my straightedge upon each one, and sight along the bottom with strong back lighting; and then mark the high spots, and flatten them very carefully, with scrapers and sanding blocks. It's also important that the course lines be integrated with their fellows to create a smooth curve across the fingerboard.

These are my final action numbers. The fingerboard is also reasonably flat in long section, and nicely curved in cross section. I am now ready to erase my pencil lines and numbers, and move on to finishing out the neck and peg box.

This is accomplished with files, scrapers, and a piece of shave grass that I've cut open, flattened and stuck to a cork block with double-sided tape.  

A few minutes of work with this gives the back of the neck and peg box a very warm, sleek feel. 

I don't touch the dyed parts in this finishing out stage, but I do give the peg box cheeks a careful going-over. (By the way, there turned out to be a nice, crisp line between the dyed bass rider and the pear peg box cheek. Same with the chanterelle tuner on the other side.)

One of the final stages of finishing out is to chamfer lightly all the inner and outer edges of the peg box with a very fine (#4) file.

I do this not only for the 'finished' look I get, but also to rid the lute of any edges and corners that might stab, slice, or otherwise maim the player. (And yes, I have seen and held lutes with such features.) On the tip of this peg box, for instance, I've not only chamfered the edges of the veneers, but also docked each corner with a single stroke of the file. 

At long last, it's time to apply a finish to the neck and peg box. I begin by masking off the body...

... and the belly. By the way, don't feel bad about the fingerboard points not being oiled along with the fingerboard. They have already received a finish, along with the belly, prior to varnishing: the one-two-punch of casein size and marienglas ground coat, described in episode 17 of this series

My finish for the neck and peg box is Tried and True (T&T) oil. I brush a fairly conservative coat on neck veneer first, then turn over and do the same with the fingerboard. I then wipe away the excess with soft cotton cloths. 

Once I've completed a coat on the neck veneer and fingerboard, I move on to the peg box. I cover the inside of the box first, then the outer surfaces, including the bass rider and chanterelle tuner.

You can see in the photo above that the logwood-dyed pear looks a little cold before oiling--an almost blue-black. But the T&T Oil really warms up the colour, and once the oiling is complete, the chanterelle tuner and bass rider match the ebony veneers really well. The result, after polishing with soft cotton, is  positively sumptuous.

I'll remove the masking and hang this lute overnight in the light box, so that the oil finish has a chance to firm up before I move on. Next stage is fitting the pegs, which--along with a few other items, perhaps--will be the subject of my next post.