F-5 Mandolin #40 172

Completed June, 2017

(click any of the thumbnails for a higher-resolution photo)

This mandolin is a Loar-style instrument with not only bells and whistles --red spruce top, flamed maple back, sides, and neck, radiused fretboard, hot hide glue construction, celluloid bindings, and some really nice inlay to dress it all off -- but with vintage looks and sound. I've lightly distressed the varnish finish, as you can see in the photos, and it truly looks like a well-played, but cared for, vintage instrument. Just strung up, the sound is impressive; when it opens up, it will live up to its looks.

Construction Photos

As is almost always the case, the construction kicks off with the selection, matching, and joining of the top and back plates with hot hide glue. The ribs are ripped to width and sanded to finished thickness, then bent over a pipe heated with a light bulb. It's important to me to bend the sides accurately enough that they will follow the pattern without extra coercion. Blocks are fitted to the rims where required, and the parts are glued together with hot hide glue. Mahogany lining is kerfed on the bandsaw.

The lining is glued in place. The rim assembly is removed from the form, and celluloid point protectors are fitted and glued in place. The back and top are cut to shape. The rim assembly is returned to the form and clamped rigidly in place. The plates' edge thickness is established on the router table.

Excess wood is hogged off with a power plane, and then the plates are roughly carved to profile on my shop-built duplicating router. The exterior of the top is refined with scrapers and sandpaper. The graduations are laid out on the inside of the plate, and thicknessing holes are drilled on the drill press. Excess wood is removed from the inside first with planes,

shifting to a scraper as the finished thickness is approached. At this point I also start measuring and tapping, listening to changes in the tone and responsiveness of the wood. When I'm satisfied with all the top's parameters, I record the information for future reference. The f-holes are marked and cut, and the tone bars are fitted. Here are the bars before gluing, simply resting where they belong; you can see how perfectly they follow the contours of the top.

The tone bars are glued in place with hot hide glue. Hot hide glue is also applied to the mating surfaces of top and sides and allowed to dry. The top and sides are clamped together, and a jet of steam is utilized to reactivate the hide glue. The neck blank is cut to shape, and the truss rod slot is routed. The peghead "ears" are glued on.

The headblock is extended with a block of maple. The cheeks of the dovetail are cut on the tablesaw, using shop-made jigs. Further fitting is done by hand, resulting in a tight fit in perfect alignment. An ebony blank is sanded to thickness for a headstock overlay, and it's cut and sanded to shape.

The celluloid three-ply peghead binding is applied one layer at a time. The outer ivoroid layer is thicker than the finished binding will be to allow for the angled cut on the peghead. The bindings are then sanded level with the ebony. Paper patterns of the inlay pieces are glued to mother-of-pearl and abalone blanks, then cut out with a jeweler's saw. The pieces are soaked in water to remove the paper.

The cut pieces are arrayed on a black background, where I can keep track of them. The pattern is traced onto the overlay, then it is routed to receive the pieces. The "wire" portion of the vine-and-wire inlay is fitted first, and then the complete inlay is set in a mixture of epoxy and ebony dust. When the epoxy has cured, the overlay is sanded level.

A cross-grain reinforcing disk is recessed into what will be the narrowest -- and most likely to break -- portion of the peghead. An ebony fretboard blank is slotted and cut to shape. Matching recesses are cut in neck and fretboard to receive carbon-fiber reinforcing bars. The truss rod is installed. The peghead veneer is glued to the peghead. The peghead is cut out on the bandsaw.

The shape is refined on the spindle sander. Holes are drilled for the tuning machines. The peghead is taken to final thickness on the spindle sander. The neck is shaped with rasps, scrapers, and sandpaper. The top is tuned both by measuring the deflection of the separate tone bars under a fixed load, and by examining the tap tone on a computer program especially designed for that task.

The resulting tone bars are of perfect shape and size. The neck is glued to the body with hot hide glue. Mahogany lining is cut to shape, kerfed on the bandsaw, and glued to the ribs. I turn my attention to the back; the outside is refined first with scrapers then with sandpaper. The graduation pattern is sketched on the inside.

Thicknessing holes are drilled using a stop on the drill press. Wood is removed first with planes, then with scrapers. As I approach finished thickness, I begin checking the graduation. As with the top, I'm also looking at a visual representation of the tap tone and checking the weight until I arrive at a back that is matched to the top and fully resonating at the proper frequencies.

The label and signature are applied, then protected with low-tack tape that will be removed after finishing. Hot hide glue is applied to the mating surfaces of sides and back, then allowed to dry. The parts are clamped together, and the glue is reactivated with a jet of steam. Block position markers are cut from mother of pearl, recessed into the fretboard, and glued in with a mixture of epoxy and ebony dust. Teflon strips protect my fret slots from being filled with the epoxy. The strips are removed, and the board is sanded to a 12" radius.

Slots for the carbon-fiber fretboard reinforcing bars are extended through the head block. The scroll is sanded, and the final shaping of the plates is done. The major portions of the binding recesses are cut with a router on a "dentist's tray" arm. The areas that must be cut by hand are marked off with a compass.

The areas inside the scroll are cut by hand, with gouges, chisels, and files. The three-ply binding is glued in one layer at a time. When the top is completed, the process is repeated on the back. Since the adhesive I'm using swells the binding, the instrument is set aside for a week or so while the binding returns to its permanent state. Three-ply binding is also applied to the fretboard.

Gold "Evo" fretwire is cut to length, notched, and pressed into a thin line of hot hide glue. An ebony fretboard extender is fitted and cut to receive the carbon fiber reinforcing. The fretboard is glued to the neck. A pickguard is fabricated, and binding is applied to the edge.

After the bindings have cured for a couple of weeks, I begin the final sanding and preparation for finishing. Just before the final sanding of the top, I fit the bridge feet to the top. As a final step in tuning, the f-holes are gradually enlarged to raise the Helmholz resonance of the air chamber to the desired pitch. The tuning machine holes are reamed to receive the string post bushings. The fretboard and front of the headstock are masked off. Masking is also quickly applied to the bulk of the body bindings. This masking isn't intended to be exact, but rather to reduce the amount of scraping later.

The stain is built starting with amber, progressing to brown and black, and then a bit of red is filled in. My intent is a slightly darker, browner, more vintage-looking color scheme than I normally apply. The temporary masking is stripped from the bindings, and the laborious task of scraping the stain from the bindings begins.

When all the bindings are scraped clean, the varnishing process begins. Oil varnish is applied in very thin coats and allowed to dry for at least a day between coats. When the varnish builds enough to allow it, I begin light sanding between very thin, brushed coats. Drying conditions aren't great just now, so coats are being applied every other day, rather than daily. When the build is sufficient, and the varnish has fully dried, the instrument is lightly sanded and polishing begins. With other work pressing, and this instrument a demo, I'm doing this in my spare moments. I've finally caught up with my other projects, and can finish this instrument. The instrument is rubbed to a nice gloss with rottenstone and oil.

When I consider the instrument to be nearly perfect, I set out to make it imperfect: I'm wearing away edges and normal wear areas with pumice to lightly distress the instrument and give it an aged appearance. I've done this a lot on my violins, but have forgotten how much extra work is involved. The tuning machines are installed. The upper section of the ebony bridge is profiled to create a compensated landing area for the strings. The frets are leveled and dressed.

A bone nut is created and antiqued. Add strings and some setup, and this one's ready to go.

Thanks for watching this project

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