DIY Network

Handmade Guitar, Part 11: Building the Neck From "Handmade Music" episode DHMM-103

	Host Jeff Wilson visits the guitar showroom at the world-famous Gruhn Guitars in Nashville, Tennessee.
	George Gruhn holds an authentic Martin D-28 built in 1937.

In this segment of DIY's Handmade Music, host Jeff Wilson visits George Gruhn at the world-famous Gruhn Guitars in Nashville to learn more about the quality of vintage guitars. Then, Lynn Dudenbostel begins work fashioning the guitar's neck out of mahogany.

Gruhn Guitars

George Gruhn, of the internationally famous Gruhn Guitars, has spent much of his life investigating the vintage guitars made by master luthiers in the 1930s and early 1940s -- and discerning what factors made those guitars so great.

"If you look at, for example, a 1937 D-28 Martin, aside from the fact that it's an aesthetically pleasing instrument," Gruhn says, "with beautiful wood and attractive lines, it is a really superb-sounding guitar. It plays physically well, and there are three basic factors that go into that: design, workmanship and materials."

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	Lynn Dudenbostel measures and marks the precise placement of the fingerboard on the neck of the guitar.
	Figure A

Building the Neck

When it comes to workmanship and materials, luthier Lynn Dudenbostel doesn't take chances or leave much room for mistakes. With the body and fingerboard of the guitar both complete, he now begins work on the guitar's neck made from a block of solid mahogany (figure A).

Materials:

Mahogany stock
Router
Band saw
Table saw
Woodworker's glue
Straight-edge
Carpenter's pencil
Safety glasses or goggles

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

Steps:

• Lynn begins with a 4x4 piece of mahogany that's 24 inches in length. On that block of wood, using an established template, he lays out the design for two guitar necks.

• With the neck-blanks laid out on the stock, he then uses a band-saw to rough-cut the shapes.
  
• Once the rough shapes have been cut out, Lynn cuts a channel down the center of the neck piece using the table saw (figure B).

• The channel is cut on the face where the fingerboard will later be mounted. The purpose of the channel is to accommodate the placement of a truss rod (figure C). "The truss rod counters the tension of the strings," says Dudenbostel, "you can either loosen or tighten it to move the neck in either direction." The truss rod will be installed, beneath the fingerboard, later in the process.

  Figure B

  Figure C

  
  
• Lynn then begins work on the neck's dovetail. With the neck piece attached to a custom fixture, and outfitted with a custom template, Lynn uses a dovetail router to rout the dovetail that will hold the neck to the body (figures D and E).

  Figure D

  Figure E

  
  
• Once the dovetail has been cut, Lynn cheks the fit of the dovetail where the neck will join the body (figure F).

• With the neck-piece dry-fit to the body, he also uses a fret-scale to take measurements to determine the precise location of the nut on the guitar's neck (figure G).

  Figure F

  Figure G

  
  
• The guitar's nut is a piece of ivory resting at the top of the fingerboard (figures H and I). It is used to keep the strings properly spaced on the span between the peg head and bridge.

  Figure H

  Figure I

  
  

  	Figure J
  	Figure K
  	Figure L
  	Figure M
  	Figure N
  	Figure O

• A peg head also slopes away from the fingerboard and the nut's position signals the start of this transition. Lynn determines the position he planes the peg head to meet the mark. Also the angle of the peg head exposes the truss rod's channel. Lynn covers the open end with an ebony plug (figure J). The peg-head veneer will cover the open end completely.

• Now Lynn marks the full width of the nut onto the neck. After spreading wood glue on the peg head he unites a rosewood veneer with the mahogany surface. This rosewood is leftover from the cutout of the back. The position of the nut dictates the placement of the veneer. When it's dry Lynn outlines a peg head design on the veneer. The template he uses (figure K) was copied from a vintage guitar.

• Before the neck is ready to meet the body Lynn must cut away part of the spruce top and mahogany head-block to accommodate the truss rod. He also uses a sharp chisel to do some final shaping on the dovetail to ensure a perfect union with the body (figure L).

• Next, the fingerboard -- which has already been cut and shaped to its final dimension -- is laid out and aligned precisely on the guitar's neck (figure M). Tiny marks are made on the fingerboard and neck to ensure proper alignment.

• At the lower end of the neck, Lynn checks to ensure that the center of the fingerboard intersects perfectly at the center of the purfling ring that surrounds the sound hole (figure N). A symmetrical intersection with the circle indicates perfect alignment.

• After a final dry-fit to ensure precise alignment, the fingerboard can finally be glued to the neck using wood glue (figure O). "Once you spread the glue," says Dudenbostel, "you need to work fast. It's one of the few times a luthier gets in a hurry!"
  

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.

Stewart MacDonald's Luthier Supply Shop
Website: www.stewmac.com

Luthier's Mercantile International, Inc.
Website: www.lmii.com

Pioneer Valley Luthier Supply Company
Website: www.pioneervalleyluthier.com

GUESTS :

Lynn Dudenbostel, Luthier
Dudenbostel Stringed Instruments
Knoxville, TN

John Arnold, Luthier
Newport, TN

Ted Davis, Luthier
Loudon, TN