Presentation on theme: "Crafting a Baroque Style Guitar by John C. Steinert Basic Instrument plan by R.E. Bruné as plan #27 from the Guild of American Luthiers."— Presentation transcript:
Crafting a Baroque Style Guitar by John C. Steinert Basic Instrument plan by R.E. Bruné as plan #27 from the Guild of American Luthiers.
The finished Marie Antoinette Baroque style guitar, Front and Rear views.
From plan side profile, a standard silicone blanket side bending mold was first created and used both to make the exterior mold and to form the guitar sides themselves. The exterior mold was used for forming the rim and also for making a plaster male mold for shaping the guitar’s back panel.
Stringers were then added following the long axis to define the external shape. The bottom contour was obtained by bending scrap spruce from mold’s perimeter to a keel profiled from the design drawing. The resultant shapes were then transferred to ¾” plywood ribs.
Ebony sides were glued to rag paper, bent on the heat blanket form, then mated to neck and end blocks. Temporary scaffolding was then hot glued while the rim shape was maintained by the mold.
Complete guitar rim assembly now removed from mold. Slight variations in the hand cut camel bone spacers caused this mismatch in tail alignment of center area strips. Later checkerboard inlay work minimized the effect visually (see insert) since top and bottom spacers were correctly aligned
A plaster of Paris mold was poured and removed from the wooden exterior mold in order to provide an exact back form. The plaster mold was then used to both heat bend spruce reinforcement strips to correct curvature and to glue and cold form ebony and ivory spacers to 32 lb rag paper backing. The strips were temporarily held in place by tape.
The back also had masking tape applied to it’s interior surface beneath rag paper. This was to mask the spruce reinforcement strip locations. An exacto knife easily removed the tape and rag paper for the reinforcement strips to be glued in place.
Gluing the spruce strips in place and photo of finished back ready to mate to the side rim.
The side rim assembly and back are glued together held by a variety of simple rubber bands and very light clamping. Pre-formed back made for a stress free fit and the entire seam could be inspected and gently tightened as necessary.
After band sawing a mahogany neck blank to rough profile, the blank is mounted to a dual taper neck shaping slide. The slide works with a microplane drum cutter and a conventional drill press to form the neck.
The heel is later cut off at a 45 angle and scrapped in favor of the Baroque style “ Ice Cream Cone” heel. The head plate core is also cut off with a V notch done with a hand pull saw. It will be reused after ebony cladding and a head plate veneer are applied. Neck shaping completed with heel and head removed. (Sorry Marie!)
A fixture was made to shape the “Ice Cream Cone” heel from a block rotated 180º about a ¼” steel rod using a drum sander and drill press. The 45º cut shown was made after the block was shaped and before the back half of the block was cut away. Shown are the three main resultant components of the neck.
The head plate with ebony cladding and ebony head plate veneer routed for checkerboard inlays top and bottom. Three pieces were ready for inlay work. 1mm thick strips of ebony and camel bone ivory are glued to parchment in the manner shown, then cut in 3 mm strips.
Resultant strips are glued to the neck pieces using sequential addition of rubber bands while clamping. The neck cutting slide is used as a holding fixture. This is done for the heel and head plate core in turn.
The 670 mm fingerboard was cut and tapered using conventional methods except for a pocket to accommodate a sound board extension to fret 9. Note sanded neck section, inlaying complete. The neck was widened slightly to carry an extra course of strings. The head stock was filed and shaped with hand tools. Twelve peg holes were drilled (6 course 11 string guitar), a modification requested by the future owner. Also, the peg holes were slanted to keep strings from touching adjacent pegs, a departure from the original design which called for a parallel line of pegs.
The bone pegs are taper fitted to each hole and the head and neck are glued together. Note: additional inlaying completes the checkerboard pattern on both sides.
The heel is shaped to fit the neck block. With inlaying completed, it is glued to the neck. The fingerboard and carbon fiber truss rod are glued in place. 3/16 “ dowels are added as locating pins and a 10-32 brass insert is installed for the bolt on neck. The completed neck shown here.
Other concessions to modern guitar building are illustrated. Ribbon lining replaces 15 side spacers in the original design. Also, the neck is to be removable with carbon fiber truss rod extending through two Dragonplate® gussets applied to the forward brace.
Two layers of (graffiti laden) linen 32 and 24 lb rag paper soaked in luthier's glue adorn the interior. The top is 45 to 50 grains per inch Sitka spruce (not split billet) with parchment strip applied giving it a distinct arch. The arch was replicated in the cross braces, one shown here.
The barber pole rosette was laid out with pieces initially glued to paper using tangent lines to the smaller circle shown here.
The whole layout was then epoxied to a back board. Added also was a thin center plate intended to provide level router base support. Routing the rosette.
The routed rosette is then placed in a similarly routed groove in the sound board. Note purflings inboard and outboard are also applied with Weldon 16. The hole is routed out and the inner lip ebonized black. The parchment rose was engineered to be removable, but to remain internal to the sound box. (Not shown) The top was then glued to the back and sides in the usual manner.
With the binding groove routed into the top, the next step was to inlay the black and white diagonals. Each piece was hand fitted for tightness, some needing minor sanding.
Note the lower bout end piece inlay work was done at the same stage as the rosette.
Body and neck now ready for finishing with lacquer. Remaining operations were fairly standard, involving application of frets, bridge and flourishes. The ebony flourishes were commissioned from a laser cutting firm. The bridge and compensated saddle are another slight departure from the original monolith design. In keeping with the Baroque spirit, the saddle was intentionally obscured by the use of black buffalo horn.
PAY DAY! Stringing it up and seeing what it sounds like. Parchment rose shown at right courtesy of Elena Dal Cortivo. Rose was modified to allow twist and drop for access to the guitar interior using balsa wood cams.
Metal crown beads were found to be uncomfortable on the peg ends. They were replaced by simpler black dots. Mr. Kent LaRue with his new Baroque style Marie Antoinette guitar.
Kent playing. Upper strap button was intentionally left off backside of upper bout. There is one dummy tuning peg (11 strings – 12 tuners) to accommodate a strap.