Friday, January 14, 2011
"Delta Boogie" Details
I've been asked recently to elaborate about details as they apply to the creation of the 'Boogie'. So, here goes.
The 'Boogie' is made from a Kristoff cigar box. By design, it is a very rough box, not smooth like typical boxes (9-1/4" wide x 9-3/4" long x 2-1/8" deep) with built-in hinge pins on the lid.
I cut a 5-1/4" hole in the center of the lid to accommodate the resonator (a small antique pie tin found in a junk store) turned upside down inside the box. The tin rests on raised wood blocks, one on each side of the box cavity, which are cut to a thickness to allow the bottom of the tin to be level with the top of the box opening. The tin is held in place by other smaller blocks glued to the resting blocks, A small gap (1/8") separates the tin from the box top opening. The purpose of the resting blocks and the top gap is to prevent sound deadening from the resonator. The tin should rest flat on the blocks to eliminate any potential buzzing.
A diamond-shaped sound hole is cut in the corner of the lid to let sound resonate.
A 1/4" hole is drilled in the center of the tin bottom to accommodate wires from the Piezo transducer pickup inside the bridge biscuit. The wires are connected to the output jack in the back of the box, which is mounted by way of a custom designed cedar plate.
The biscuit is 2" in diameter, made from three glued pieces of wood: a 3/16" birch plywood base; 1/8" balsa mid-piece (each has a 1" hole in carved in the center to accept the pickup, which is kept in place with a healthy dose of silicon filler); and a 1/8" solid piece of Spanish cedar for the top of the biscuit (from the inside divider pieces of the cigar box). A 1/4" piece of solid brass rod is used as a bridge saddle on which the strings rest. The biscuit floats on the tin - not glued to it.
The neck is a 'set' neck, which is attached with screws to a block of oak (1-3/4" cube) glued to the inside of the box on the neck end.
I chose 1/2" x 1-1/2" oak as a neck with 1/4" x 1-1/2" poplar as the fingerboard. As with all necks I produce, I chose stock that has a slight hump in the wood for the top of the neck, which straightens under string tension, so that I don't have to screw around with a truss rod (this works well on 3- and 4-string guitars), anything with more strings would require a rod. I chose to add a little cedar veneer to the neck for decoration.
Like all my creations, I use BBs as fret markers glued in depressions on the leading edge of the fretboard. No special reason, just my quirky design. It works for me and keeps the surface of the fretboard clean.
The nut is also 1/4" brass rod resting on a cedar bed to lift it enough to allow the strings to clear the first fret.
I never attach the nut or bridge until the neck, complete with frets, is attached to the body. Then I use a straightedge on the fretboard to determine how much thickness I want at the nut for strings to clear the frets, and so the saddle height is enough to allow 1/8" string clearance at the 12th fret, on a regular guitar (I like close action), and whatever I desire for action when using a slide to comfortably play without mashing the strings on the frets.
The headstock is a simple design with three holes drilled for tuners. I used a Floyd Rose type string tree to snug the strings to the nut.
The tailstock is a stainless steel door strike screwed to the back of the box, with three holes drilled it it to accept the strings.
Strap pins are simple buttons acquired at Hobby Lobby.
I use the #5, 4, and 3 strings (A, D, G) from an acoustic set of six medium gauge strings. There are many inexpensive brands to choose from, and I have had a lot of success with Guitar Fetish strings.
The 'Boogie' is open tuned G - D - g, which is my preference.