Building an Early Lacôte Guitar Part 3

Pat Bianculli's 1823 Lacote

The flush fingerboard of Pat Bianculli's Lacôte is a hold-over from baroque era in which it was important to keep the strings close to the soundboard. Utilizing a low bridge and a flush fingerboard accomplished this. I find it curious that this feature endured as long as it did. The transition to six single strings had started thirty years previous to this. The development of a saddle and fixed metal frets swiftly led to the raised fingerboard. Yet, guitar builders continued to use flush fingerboards even though it is a feature that made demands on musicians and luthiers alike. Perhaps guitarists and makers were hesitant to discard this feature because the aesthetics of both tone and sight were pleasing, evocative, intimate? I had not built this style of Lacôte before and that was the attraction for me.

Constructing a guitar with a flush fingerboard requires a particular sequence of assembly. This photo appeared in an earlier post but I am using it again to show that I had glued the fingerboard in place even before I started the purfling. This was necessary  because I needed to level the transition from the fingerboard to the soundboard before I assembled the purfling. Doing so afterward might have damaged the delicately mitred purfling corners. 

 I had also slotted the fingerboard previously and hamered in the frets. The edge of the last fingerboard fret is visible in the photo.

original bridge

The bridge on Pat's guitar was a replacement and seemed to be constructed a little larger than Lacôte's standard size.  

The front edge of Lacôte bridges are smoothly rounded with the saddle slot cut several millimeters in from the front edge. The saddle on the replacement bridge was cut considerably further in from the edge than normal.

I consulted my notes and museum plans and designed a bridge in the Lacôte size and style. When I make any bridge with a saddle I leave the front edge square and the top surface, where the saddle slot will be, flat.

I do this so I can work out the compensation of each string in order to achieve good intonation. I use triangular shaped pieces of nut  bone as movable saddles. Placing them on the surface that I had left flat I maneuvered them into positions that gave the correct intonation for each string. I duplicated these positions by angling the saddle slot from closest to the front of the bridge on the treble side to furtherest on the bass side. The finished saddle is 2mm wide so I will contour the top of the saddle to further refine the intonation on the finished instrument.

The last stage of the fretting was the most difficult to do, yet when finished, the most satisfying and visually one of the most pleasing features of this style of guitar.

On baroque era guitars the belly frets are slivers of ebony or boxwood glued on the surface, but sometimes inset, on the soundboard. Once metal frets were used on the fretboard they needed to be continued onto the soundboard for consistency of tone. Keep in mind that 19th century frets were not the T-shaped fret of our day but straight pieces of metal that were about 0.8mm thick. The spruce of the soundboard is too soft to support metal frets of any kind adequately. Lacôte bordered his bar frets with ebony. This ebony/metal fret/ebony sandwich is a little less than 3mm wide. I wanted to insure that my belly frets played in tune so my problem was how to inset a 3mm wide fret assembly in the soundboard precisely in the correct location.  

I laid out the fret positions in pencil and after double checking for accuracy I scribed over the pencil with a knife being careful to respect the length of each fret. Then I widened the scribe line with a razor saw and continued with successively thicker saws until I had broadened the original line to 0.9mm. This is the width necessary to press fit a T-fret into the soundboard. I still needed to add the ebony supports that were also 0.9mm wide. I cut pieces of a broken bandsaw that fit exactly in the fret slot but a little raised above the surface. I placed a piece of the ebony border against each side of the temporary metal "fret" and carefully scribed a thin knife line. This delineated the borders of the recess I would cut for the ebony/fret/ebony sandwich. The sequence of steps is demonstrated in the photo. Once everything was prepared I waxed the metal spacer and glued all three pieces into the slots.

When the glue dried I removed the metal spacers, planed the ebony flush with the soundboard and inserted the T-frets with a little glue.

Next time I'll explain the varnishing and post detail photos of the finished guitar.

Building an Early Lacôte Guitar - Part 2

In my last post I had assembled the guitar body and finished the neck and peghead. Before I glued the neck onto the body I checked the strength of the neck. Wedging the heel against a notch in my workbench I tried to bow the neck -- mimicing the pull of the strings -- by pressing against the back of the peghead with my thumbs and down on the face of the peghead with my other fingers. The neck bowed a little less than a millimeter from level. I was satisfied as this is what I expected. If it had bowed more than that I would have routed a recess in the top surface and installed a long rectangular ebony strengthening rod. I glued the neck to the body using a screw through the front block into the heel by maneuvering the screw driver through the soundhole. At this stage the neck is plain wood. Eventually I will lacquer it black like the original that I am copying.

1823 Lacôte

The purfling detail on the original guitar is composed of five bands of ebony and five of ivory that wrap around the perimeter of the guitar body in one piece. Each band is about 0.7mm thick. I substituted holly for ivory. I make my own banding by band sawing lengths of appropriate woods with widths of 30 or 40 millimeters. After smoothing and thinning to the required thickness I stack them one on the other, as many as 10 high, and glue them together. After they have dried I square the two rough edges and saw off several pieces and smoothed with a small plane. Each piece is then composed of multiple bands that only need to be soaked in warm water to dissolve the glue and then dried or bent while still damp.

Even though I carefully prepared the banding I found discrepancies in the thickness of a number of pieces. If I were using a decorative edging of 3 to 5 pieces of banding I wouldn't worry about a tenth of a millimeter here or there. But multiplied over 10 pieces a small error can cause problems. I use a home-made device to check and re-size each piece of banding. The tool is composed of a block of wood with a flat bottomed ramp cut into the block at a 45 degree angle. A scraping blade is clamped in a position over the exit of the ramp leaving a gap through which the thin strip of banding can be passed. High spots are scraped off by the blade. It is a primitive tool but with patience it will turn out perfect work.

The width of the purfling is a little wider than 8 mm composed of ten pieces of ebony/holly banding. A final band of ebony that is a little thicker and, of course, deeper is added to the edge.

I use a small router fitted with a simple guide to cut the rabbet. Setting the guide to the proper depth I make a series of passes gradually widening the recess. I test fit the 10 ebony/holly bands and stop when the wider ebony piece fits comfortably.

The purfling is intended to wrap around the soundboard tongue with four mitred corners. This is a tricky procedure that displays the luthier's skill. If it is well done it looks pretty classy.
In this photo I masked the corner of the  rabbet with cellophane tape and glued the last 30 - 40 mm of the pre-bent banding together. I wedged it temporarily into the recess so it would dry in the proper alignment.

I lifted the banding from the recess, peeled off the cellophane mask and cut the end of the assembled banding to the correct angle. Once that was done I could proceed to glue the entire assembly in place. It is necessary to work slowly and methodically making sure that each piece of banding is covered with a layer of thin glue and that each piece in turn is properly seated in the recess.

Fitting the mitred banding perfectly around the soundboard tongue was complicated by discrepancies in the thickness of the ends of each piece of banding.  I found it necessary to fit them individually -- each mitred piece matching its mate.

Once all of the banding was in place and well dried I scraped it flush with the soundboard.

The rosette is composed in the same style of multiple bands of ebony/holly except that they are narrower and present greater difficulty in making and assembling. There are 20 bands, plus the wider ebony band that edges the hole. It measures 13.5 wide.

I assembled the rosette before I finished thicknessing the soundboard. This allowed me a little lee-way with the depth of the recess and the process of levelling the face once I was finished or if something were to go wrong. I routed the recess to the maximum  outside diameter and took off a little extra toward the inside as well. This allowed for the expansion that the thickness of the glue might cause. Lacôte assembled his rosette rings so that the ends, which are faintly visible, were spaced randomly around the circumference in order to further obscure them and I did the same. Using pre-bent bands I started at outside  and worked in, one at a time, cutting the pieces to length with opposing bevels so as to avoid making a band either too long or too short. It was not easy going. I quickly developed sticky fingers which made it difficult to do everything including pressing the most recent ring in place against its neighbour. When I had all of the bands in place there was a little space left that I filled with thin strips of styrene until the glue dried. I wasn't happy with the result. Every imperfection showed up. A kink or two here and there and several gaps between bands as well. I routed it out and started over.

Next time, I'll fret the neck including the embedded soundboard frets. I'll also describe staining and varnishing the body and lacquering the neck.