DIY Network

Handmade Guitar, Part 2: Top, Back and Inlays From "Handmade Music" episode DHMM-101

	Guitars have been known to be made from unconventional materials. Host Jeff Wilson holds a rare "Ryman Guitar" made using wood from some of the wooden pews that were removed from the original Ryman Auditorium in Nashville.
	Marquetry inlays are one of the distinctive visual features of our handmade vintage-guitar replica. The name for the inlay around the guitar's sound-hole is purfling.

Master luthier Lynn Dudenbostel builds guitars by hand, and he only builds one at a time. In this four-episode series, we see the step-by-step process by which Lynn builds a guitar in the style of the classic Martin D-28.

In his workshop, Lynn emulates the techniques of craftsmen who came before him to recapture that hard-to-describe magic found in classic vintage guitars. In this segment, he continues work on the guitar's top, back and inlays.

Materials:

Rosewood stock
Template
Band saw
Drum sander
Plunge router
Hand-held drill
Circle cutter
Block plane
Cabinet scraper
Hammer
Clamps
Wood glue
Sandpaper, 100-grit
Acetone-based glue

Safety Alert: Always wear safety goggles or safety glasses when
working with wood, power-tools, saws, drills, routers, etc.

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	Figure A
	Figure B
	Figure C
	Figure D

Guitar Back

"Wood selection," says Dudenbostel, "is one of the single most important things that's going to influence the sound of your instrument." So far we've seen Lynn's work on the thin sheets of red spruce -- the wood that forms the top of the guitar and does much to provide the instrument's unique sound. But guitars are made from a number of materials. The process for making the back of our Martin D-28 replica is essentially the same as that used to make the top. The main difference is in wood selection. For this section of the instrument, Lynn selected East-Indian rosewood. As with the top, the slices of wood used to make the back of the guitar are a book-matched pair (figure A).

• Using the template from his guitar plans, Lynn marks the outline of the guitar's back onto the rosewood (figure B). He then planes the joining edges perfectly smooth using a block plane, and joins the mirror-image pieces together using glue, clamps and straight rails.

• The joined pieces are passed through the thickness-sander. In it's raw form, the guitar back is about 200/1000-inch thick, but once sanding is finished it will be down to about 90/1000-inch. A caliper is used to ensure proper and exact thickness (figure C).

  Lynn then cuts out the guitar's back the band saw (figure D), saving the scraps to make brace pieces later on.
  

  	Figure F
  	Figure G

• With the back cut out, work can begin on some of the many decorative touches that will be added to this beautiful hand-made instrument. The traditional look for this vintage guitar includes a marquetry strip down the center of the guitar's back (figure E). Pre-made strips like this can be purchased from a luthier-supply shop.

• A channel must be cut down the center of the back -- along the joint -- to hold the strip. Lynn cuts the channel using a plunge router. After two precise passes with the router, there is room to insert the inlay. Lynn fills the channel with glue and inserts the strip. The strip should fit snugly and, because it's slightly taller than the depth of the channel, rise just above the back's surface (figure F).

• After the strip has been clamped down, and the glue has dried fully, the inlay is planed flush with the surface of the back using a block plane (figure G) followed by a cabinet scraper. Once finished, the inlay is perfectly even with the back's rosewood surface.
  
• With the back-strip inlay done, work can begin on the ornate inlay for the top. The technical name for the inlay around the guitar's sound-hole is purfling. The first step is to locate the position for the exact center of the sound-hole. Lynn then uses a hand-drill to drill a small hole at that exact location. He then uses a circle-cutting fixture attached to a rotary tool to cut three channels around the sound hole (figures H and I). The purfling, made from a laminated fiber, will be embedded into these channels.

  Figure H

  Figure I

  
  

  	Figure J
  	Figure K
  	Figure L
  	Figure M

• Acetone-based glue is placed in the channels to hold the purfling, but it's critical to achieve and maintain a snug fit even without the glue. To get the look he wants, Lynn groups several pieces together inside the center channel, and gently eases them into place using a tap-hammer (figure J).

• When the top was originally run through a thickness sander, it was intentionally left just a little thick so that it can now be scraped and sanded with the purfling in place. In that way, the purfling can be made perfectly flush with the surface of the red-spruce top.

• The center of the sound hole is removed using the circle-cutter and rotary tool (figure K).

• Relevant information about each guitar Lynn makes is recorded on this piece of rosewood (figure L) that's been removed to make the sound hole. The circle of wood, complete with notes, is kept on file in case Lynn needs to reference a past work.

• Lynn radiuses the sound hole's edge using 100-grit sandpaper (figure M) to soften and eliminate the square corners.

• With the inlays in place, and the top's sound hole cut out, the top (figure N) and back have begun to take shape. Both, however, still have some work that needs to be done.
  

  	Figure N
  	The traditional look for this vintage guitar includes a marquetry strip down the center of the guitar's back.

RESOURCES :

Kentucky Thunder
For more information on the band that appeared in DIY's Handmade Music, Kentucky Thunder -- and to hear streaming audio and download samples of their music -- visit the website for Skaggs Family Records, www.skaggsfamilyrecords.com.

GUESTS :

Lynn Dudenbostel, Luthier
Dudenbostel Stringed Instruments
Knoxville, TN

John Arnold, Luthier
Newport, TN

Ted Davis, Luthier
Loudon, TN