Tom Hoelle: Harp Guitar!

 Tom chronicles a new project...

 This page has lots of pictures!  Please allow time to load!

The Project: 

Intrigued by the possibilities of a harp guitar, with it's extended range (in both directions, in some cases), and knowing you can't just walk into a music store and buy one, I decided to try building one myself!  I cleaned out the old workshop, blew the dust off of some of my old tools and got ready to go to work.

First things first... I had no idea how to brace one of these things and there's so many other questions to be answered, I decided to get some plans and study them closely!  I turned to Gregg Miner, otherwise known as the Harp Guitar Pope!  He maintains an incredibly extensive (and really cool) web-site dedicated to Harp Guitars and also has several plans as well as sets of tone wood that's been cut large enough for one of these custom builds!  I decided to base my "custom" harp guitar build on the Sullivan-Elliot 20 string model originally built in 1986 for the amazing harp-guitarist John Doan!  So, I got those plans from Gregg and then later (after building my courage! lol) I went back to him for Sitka Spruce for the top as well as Honduras Mahogany for the back and sides.

I also decided to keep a camera in the shop to document the process as I go...

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...skip to Page 2: Top and Back (with bracing, binding and rosettes)

...or skip to Page 3: Components, Assembly, Finish and Setup

Page 1: Fret board, Neck and Sides (framework)

I'll start by doing some inlay work in the fret board, following that by carving out the neck.  Then when I bend the sides into position, I'll be able to join it all together to form the basic framework of the instrument.  Adding kerfed lining preps it for installation of the top and back.

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The Fret Board: 

 I had seen a beautiful vine inlay pattern on a picture of a similar harp guitar and thought it looked so good that I wanted to try to do my own version of it!  I used pink Mother of Pearl for the leaves and black pearl for the vine.  By the time it got inset into the fret board and sanded flush, you couldn't tell much difference in the colors, but overall it looks pretty good and should really look cool on the finished instrument!  Also, since I planned to use curly maple binding on the guitar's body, I added the same beautiful binding to the fret board to help bring it all together into a single cohesive look for the finished instrument.

One departure from the original plans would be the use of a 25.4" scale length.  The original plans called for 650 mm, slightly (app 5 mm) longer.  Also, the width of the original Sullivan-Elliot plan's neck was much wider than I would have preferred, so I took some measurements from some other favorite guitars and narrowed my fret board's width to a "compromise" of 1.800" at the nut.

Here's the fret board blank and some mother of pearl of various colors.

Here's the vine pattern I drew out on paper...

First, I made copies of the vine pattern and cut them up into individual pieces.  These were glued to the pearl blanks to use as guides.  The pieces of the pattern are then sawed from the blanks with a fine jeweler's saw and laid out on the fret board blank...

Inlaying the pearl vine pattern into the fret board...  The fret board is painted in a bright contrasting color using tempera paint.  The pieces are then glued on top.  When a scribe is traced around the pattern, the pearl can then be removed, leaving a sharp contrasting outline in the paint to use as a guide for routing the cavities.  Once all the cavities have been routed, and the pieces have been fitted into their respective cavities, black dye is mixed with epoxy to glue them in place.  Finally sanded flush, the pearl inlay can be seen emerging from the rough painted surface!

Trimming the fret board to size and adding the binding...  A fret saw is used to clear the fret slots of any paint, glue or overhanging pearl that may be blocking them.  A band saw is then used to cut the sides away and establish the fret board width.  Sanding the edges flat preps for the binding, which is glued and clamped solid.  The binding must then be sanded flush to the rest of the fret board, both top and bottom.

And finally, installing the frets...  Frets are cut to length, the tang is trimmed near the edges (where the binding is), they're filed clean and fitted.  Finally, a bench top drill press is used to press the frets home!

The finished fret board!

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 The Neck: 

 The plans called for a neck carved from a single piece of mahogany... that means a piece was needed that was 4 inches thick and 10 inches wide!  After an extensive internet search I found a beautiful piece of Honduras Mahogany that would suit my needs perfectly.  It was longer than I needed (4 feet long!) but I figured that would leave enough extra wood to do a second neck in case I screwed up the first one!  lol 

Carving a complex neck of this nature looked to be a daunting task, but slow, steady work (measure twice, cut once) proved to be fruitful.  I stayed fairly close to the original Sullivan-Elliot plans for the neck, with the only notable exceptions being the neck width (to accommodate the narrower fret board) and a Stew-Mac 2 way adjustable truss rod accessed from a small hole in the headstock relief.

Here's the huge Honduras Mahogany block that would become the neck and structural blocks!

Roughing out a neck...  The pattern is transferred to the face of the wood and a hand saw is used to cut a "slot" wide enough for the band saw to gain access for an initial rough cut of this huge piece to get it to a more manageable size.  That roughed out piece can then be trimmed closer to the transferred pattern.  Leaving a temporary "flat" on one edge allows the piece to be turned on it's side to continue band sawing the rough cut of the neck's back side.  From there, a series of rasps and sanding will bring the neck to it's final shape.

Contouring the head stock...  Using a Dremel router to rough out the tuner shelf.  The final contouring is then done by hand with a curved rasp.

Routing for the nut, the headstock relief and the truss rod...

Headstock veneer... Bolivian Rosewood!  I found a beautiful piece of 1/8" thick Bolivian Rosewood that would make a nice contrast to the mahogany of the neck.  Rough cut to shape, glued in place and then finally trimmed and sanded flush to the contour of the headstock.

A glimpse of what the finished headstock will look like!

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Structural Blocks: 

The super treble tuner block is a 1.5 inch thick piece of mahogany that appears as a "shelf" and serves to support the super treble tuners. Using the drop from the neck, I first cut the Honduras Mahogany block's contour at full thickness, sanded it clean, then finally cut to finish thickness.  This gave me a 2 pieces with the exact same contour... one for the tuner shelf and one to use for a lower support within the guitar's framework.

Sanity check... laying out the pieces together over the full scale plans.

Bolivian Rosewood cap for the Super Treble Tuner shelf...  To match the headstock, a cap of Bolivian Rosewood (from the same piece) is glued to the top of the super treble tuner shelf and trimmed flush.

The end block and mid-side supports were simple pieces of mahogany, also cut from drop from the neck, sanded clean at full thickness.

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The Sides: 

One of my more radical planned departures from the original Sullivan-Elliott design was to make the top rim (bass side) from one continuous piece of wood, rather than having a seam at the waist as the original plans called for.  This should result in a slightly asymmetrical, but beautifully smooth, curved shape.

I'll be using Honduras Mahogany for the back and sides.  The original instrument used African Blackwood, but Honduras Mahogany has been a staple for instrument building for centuries... due to it's stability, workability and most importantly, the balanced tone that it offers in the finished instrument.

And then there's the overall size... in an effort to enlarge the sound box, I cut the sides 0.100" wider (to increase the body's depth) and widened the lower bout to app 16.25", about a 1/2" larger than it's plans called for... as well as about 1/2" increase in the body's overall  length.  These dimensions are more in line with some other favorite instruments of mine and I hope will bring out plenty of tone!

Back and side lumber (Honduras Mahogany) as received, at about .200" thick...

Prepping the side wood... the wood is first thickness planed down to about .100" thick.  Then sanded and scraped down to about .090".

Trimming to size...  A band saw is used to rough cut the sides to a constant width... next, the length of the individual pieces are laid out and cut off.  And finally, back to the band saw to cut the final (tapered) width for each piece.

Prepping to bend...  the intended pattern is transferred to a piece of plywood using carbon paper.  This will serve as a guide for the individual pieces.  The pieces are laid out on the plywood so there's no confusion about what goes where or which end is which once the bending begins.  The bending iron is heated to between 350 and 400 degrees F... and we're ready to begin.

Let the bending begin...  First, the sides are soaked in water, one piece at a time, for about 10 minutes.  A bottle of water will also be kept close by for frequent misting of the wood while bending is underway.  A strap of stainless steel sheet stock is held behind the wood while bending (for support and to help keep the water in when it starts to steam).  Working slowly and carefully, each piece is laid out over the pattern before starting the next.

The bent sides laid out over the pattern... and my harp-guitar begins to take shape!

Gluing the tail-block...  After trimming the edges of the rims, they're carefully positioned and glued to the tail block.  This firmly and finally establishes the overall width of the finished instrument (16.25" for this one).  The original plans called for a mid-side support at the seam of the 2 piece top rim.  Even though my modified version has a single piece top rim, I felt it still beneficial to place a mid-side support at the bend in that top rim due to it's extreme length.

Kerfed lining... this forms the ledge that the top and back will mount on.  I chose mahogany for the back ledge and spruce for the top.  Clothespins are used to supplement the clamps to glue these strips in place.  Once the glue sets up, the edges are filed and sanded flush to form a good solid ledge for the top and back to mount on.

And the rims are coming together...

The End Graft... again, Bolivian Rosewood is chosen for the end graft to match the headstock and super-treble tuner shelf.  I also decided to go with a somewhat oversized piece to match the general appearance of the instrument.  So a piece is cut to size and clamped to the guitar's end to use as a saw guide.  A fret saw is then used to saw through the rim "to" the end block (not "through" the end block).  Then a small chisel can be used to chisel away the rim material to form the cavity.  A trial fit with strips of black and white purfling on either side and we're ready to glue.

Gluing the end graft into the cavity... includes the purfling.  Plenty of clamps hold the pieces in place while the glue sets up.  Filing the edges flush and then sanding the surface to match the rims...

The end graft...

Assembling and installing Super Treble Tuner Shelf...

Finished shelf installed...

The complete framework... with neck, headstock and attached rims... (the fret board is sitting in place for illustration)

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Continue on to Page 2: The Top and Back, (with bracing, binding and rosettes)

...or skip to Page 3: Components, Assembly, Finish and Setup

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