The Baroque Lute Fingerboard

The hands-on technique of cambering the neck of baroque lutes doesn't lend itself to a photographic explanation. I only took a few photos while I was cambering the neck for the Jauch because it was difficult to see the details. But on one of my research trips I took photos of the fingerboard camber on two well known lutes:  Thomas Edlinger, No. 497, in Leipzig and the swan-neck lute by Sebastian Schelle, MI 46 in Nuremberg.

This is the nut end of the Schelle fingerboard. The curvature of both the nut and the ivory inlaid panel show the degree and evenness of the camber. I measured the height to be well over 4mm. The fingerboard is 78mm wide at this point.

The height of camber at the neck joint of MI 46 is over 2mm and exhibits the same evenness as at the nut. The neck width is 105mm.

These measurements are estimates because the rounded edges of the fingerboard do not allow exactness.

Here's a sample of two necks. The one underneath is the neck of the Jauch that I am building. I have cut out the recess for the triple nut extension and except for final smoothing of the fingerboard surface and rounding of the bass edge, it is finished. The one on top is from one of my theorbos. Unfortunately, the lute was left leaning upright in a corner and fell over, splitting the area of the neck at the back of the recess for the extension. Re-gluing this type of damage always leaves the joint weak, so I replaced the neck, but saved the artifact.

 I put a fairly high camber on the theorbo neck. This was requested by the client. But you will notice that it is unbalanced. The camber on the bass side flattens out a little which leaves the bass side of the neck thicker. This is intentional. There is no need to continue the same degree of camber on the bass side because the fretted strings stop 2/3 of the way across the neck as denoted by the recess for the nut. The extra wood on the bass side serves to strengthen the neck.

When I glue the neck in place its top surface is on the same plane as the top surface of the side ribs. In order to build a camber into the neck some makers glue a thin wood slab on top of the neck that is then shaped to the desired camber. But the higher the strings are above the plane of the lute, the more upward pull there is on the neck.

Photo: German National Museum, Nuremberg 

This is a restoration photo of the bare neck of the Sebastian Schelle, MI 46. The smudges are glue "shadows" of the inlaid ivory design left on the surface after the fingerboard was removed. On the right end of the neck you can see the recess for the nut and the curvature of the camber. In this example Schelle created the camber directly from the core wood rather than from an added slab. The advantage to this method is that those strings that lie farther from the neck center are closer to the plane of the lute. The top string at the nut, for example, actually lies below the plane. The second string may as well. On lutes with 11 courses on the fingerboard several of the lower courses may lie close to or below the plane of the lute. The over-all effect is to lessen the total upward pull on the neck.

The technique for cambering the fingerboard calls for patience and precision. Whatever the height of the camber is at the nut end of the fingerboard the camber must be continued, to some degree of curvature, the length of the neck and across the front block area. Otherwise, the top and bottom strings will lie very close to or on the neck.

I secure the lute in a cradle and work from the front. Using a block plane with a fine setting I start cambering the neck from the nut area down the length of the neck, across the front block and on to the top edge of the side ribs. Progress is slow as I must check frequently for accuracy. Across the neck I use a straight-edge to eye-ball the camber. In the photo, in which I am beginning to glue the fingerboard in place, you can see four pencil lines on the neck wood. These represent the second, fourth, sixth and eighth courses. I use these as guides to determine the levelness along the axis of the neck (see previous photo). When I was confident the camber was accurate I bent a piece of 2mm thick ebony over a hot pipe and glued the fingerboard in three stages as was shown and described in an earlier post.

My clients are not unanimous about the degree of camber and I construct variations.  Historical lutes also exhibit a variety of cambers both at the nut and the neck joint.

The degree of camber at the nut on this lute by Thomas Edlinger, No. 497 in Leipzig is very much like the Schelle.

 But at the neck joint the camber has flattened, relatively more, than the Schelle and is only a millimeter or so high.



All photos by the author unless otherwise noted.

The Baroque Lute Neck

The design of the baroque lute neck is anything but simple. The fingerboard is cambered from side to side for ease of barring chords. It is thin in the area closest to the nut becoming gradually thicker toward the joint with the bowl. The back of the neck is shaped for comfort. Those are fundamental attributes. Added to this are the preferences of individual lutenists and luthiers.

I work within defined limits for each feature. The thickness of the finished neck (fingerboard, spruce core and  veneer covering) at the first fret is under 19mm. The thickness at the joint to the bowl is under 29mm. These are measurements for large lutes. I think that necks that are thicker will be uncomfortable. If thinner, the structural integrity will be threatened. Naturally this doesn't suit all lutenist. But I have found that  compromise can be achieved by thoughtfully shaping the neck's contour.

I start with a plank of aircraft grade sitka spruce  that is straight and quartered with about 20-24 growth lines per inch. Usually I cut narrower pieces from several planks and re-glue them into a neck-size piece. This relieves any tension that might be in the wood. Having already beveled the front of the lute bowl to the proper width and angle, first with a back saw and finished with a block plane, I then cut the matching angle on the neck wood  using the same tools. I glue and screw tabs to the top of the neck block to help hold the neck in position while it is being shaped and adjusted.

With the rough neck material tack-glued to the front block and held level by the tabs, I drill a hole through the block and into the neck.  Once a screw is inserted I scribe around the joint delineating the contour of the neck. With the contour marked on both ends it is a quick task to remove the excess wood, first with a larger plane and then finishing with a block plane and a thin steel scraper that can flex over the contour or with sandpaper. 

I have never found it easy to apply veneer to the back of a lute neck. There are so many steps that are necessary to assure a good result. Perhaps I make it more difficult than it need be. I bandsaw my own veneer from 3 inch wide ebony boards that are sold as fingerboard stock for bass guitars. I finish the rough sawn pieces to a thickness of 1mm or a little less and bend them over a hot pipe using shaped cauls to ease the ebony into the proper curve.

Since the fingerboard stock is narrower than most lute necks it is necessary to use multiple pieces. I glue each on separately. Here the center piece is strapped down with elastic tape while the glue dries.

Removing the glue squeeze-out is done after the glue dries.

I apply a wet strip of cloth to the edge of the veneer and leave it to soften the glue for a few minutes. Then I run a hot knife along the edge. Any dried squeeze-out is liquified and can be wiped off.

The two edge pieces are bent and glued in place in the same way.

There is one last detail. I like the edges of my

necks to have a substantial roundness.  This is difficult to do with veneer because there is always the risk of it splitting when it is forced over a rounded edge. I solve the problem by planing the edges of the neck flat and adding strips of ebony. These are then contoured flush with the veneer surface. The strip on the right side is still "as glued" while the one on the left is finished.

When the fingerboard is glued on there is a solid edge of ebony that can be nicely rounded.

Next time I will describe my technique for cambering the fingerboard.