DIY Network

Handmade Mandolin, Part 9: Neck, Fingerboard and Peg-Head From "Handmade Music" episode DHMM-107

	Luthier Lynn Dudenbostel enters the final stages in the building of a handmade mandolin based on the classic Gibson F5 model. In this segment, the final details are added to the neck, fingerboard and peg-head. The neck is then joined to the instrument's body using an precision-carved dovetail joint.
	Andy Leftwich, mandolin virtuoso with the band Kentucky Thunder, samples the tone of a newly made Dudenbostel mandolin.

Thus far in the mandolin series, we've learned a great deal from one of America's great luthiers, Lynn Dudenbostel. With his guidance, we've learned the finer points of hand-building mandolins following in the traditions of the master instrument-builders of the 1920s and '30s.

In this episode of DIY's Handmade Music, viewers see the final steps in the building of a mandolin as Lynn joins the neck with the body of the instrument and adds the incredibly intricate inlay to the peg head. In the concluding segments, Lynn reveals "trade secrets" that are keys to creating a perfect finish. Finally, we find out just how good the mandolin sounds when the bluegrass band Kentucky Thunder christens the instrument in a Nashville recording studio.

In this first segment, Lynn completes the carving of the neck, adds the fingerboard and creates the inlay for the peg-head.

Materials:

Band saw
Drill press with sanding attachment
Woodworker's hand-tools -- files, rasps, hand scrapers, etc.
Sandpaper
Sanding block
Mother of pearl
Jeweler's saw
Forceps
Clamps
Instrument-maker's hide glue
Epoxy glue
Cocobolo-wood dust
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.

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Neck, Fingerboard and Peg-Head

• So far, Lynn has built the mandolin's body and partially completed neck. In the previous segment, Lynn explained that ninety percent of the neck-carving can be done in about three hours, but that last ten percent, with it's fine detail work, could take quite a bit more time. That's the stage the Lynn now undertakes as the neck begins to take on its final shape (figures A and B).

  When building an instrument, the musician is always on Lynn's mind so, while calipers and measurements can be used, nothing lets him know he's finished more than his own hand grasping the neck. When it feels right and feels like it's ready to be played, Lynn is finished carving.

  Figure A

  Figure B

  
  
  

• With the carving of the neck complete, Lynn takes care of the finer details. Sanding will brings the neck closer to perfection. He does the major of the sanding on the drill press (figure C), a process that takes Lynn only about 15 minutes.

• He follows this up with detailed hand-sanding (figure D), which may take a couple of hours.

  Figure C

  Figure D

  
  

  Figure E

  
  
• Lynn's attention now turns to the peg head. To accept the mandolin's tuners that will be installed later, holes were pre-drilled earlier in the veneer on the face of the peg head. Now, using the drill press, Lynn drills the holes the rest of the way through the peg head (figure E) -- i.e., through the maple stock and the back veneer.
  

  Figure F

  
  
• At this point, Lynn goes back to the mandolin's body and dry-fits the neck to the body. If necessary, he can make minor adjustments to the dovetail, or add tiny wood shims, to ensure a tight, seamless fit. Once he's determined that the fit is good, he applies hot hide-glue to the faces of the dovetail on the body section (figure F) and to the heel of the neck piece. (Hide-glue, which is made from ground animal hides, is ideal for soft-wood applications.)
  
  
• As soon as the glue is applied, Lynn joins the neck the body (figures G and H). The pieces are clamped carefully and left to dry overnight.

  Figure G

  Figure H

  
  

  	Figure I
  	Figure J

  
  
• With the neck and the body joined there's still one critical piece left to make before attaching the fingerboard to the neck -- the fingerboard extension which is characteristic of the F5-style mandolin. This raised piece is placed on the mandolin top, directly onto the spruce (figure I), where it butts against the 15th-fret cross-piece and supports the fingerboard. Lynn makes this piece from a piece of maple and glues it to the end of the fingerboard. "This was one of the big developments of the F5 in 1922," says Lynn, "to have a fingerboard extension that wasn't glued directly to the top of the instrument. That gives more surface area, that's free to vibrate, to the top of the instrument, and gives a different sound."

• Once the extension has been added, and the glue has dried, Lynn uses a sanding block to level the top surface of the extension so that its perfectly flush with the support for the fingerboard (figure J). "I try to leave just a few thousandths of an inch high," says Lynn, "so that I can sand it down to the plane of the fingerboard."
  
  
• With the extension glued in place and sanded flush, the next step is to install the fingerboard. Lynn lines up the fingerboard in dry-fit (figure K), and checks the alignment very carefully (figure L). Lynn is emphatic about conducting meticulous dry-fits before gluing. "Always fit everything before you glue it," he says. "Once you put glue on and assemble some of these joints, such as a dovetail, even just a few seconds after you slide it together, it's near impossible to take it apart."

• Once the fingerboard is glued in place, it's left to dry overnight.

  Figure K

  Figure L

  
  
  

Next, Lynn begins work on the ornate inlay for the mandolin's peg head.

• In some cases, the mandolin's inlay helps with identification. In the case of a Dudenbostel mandolin, Lynn inserts mother-of-pearl cutouts of his name into the instrument's peg head (figure M). He first cuts the channel using a rotary tool, then places the inlay in the channel using a mix of epoxy and cocobolo dust.

• Once glue has dried, Lynn sands the surface using 150-grit sandpaper. Once sanded flush with the wood, the inlaid letters really stand out. This effect is appears especially dramatic when the wood surface gets darkened with a damp rag that's used to remove the excess dust (figure N).

  Figure M

  Figure N

  
  

  	Figure O
  	Figure P
  	Figure Q
  	Mandolins are certainly judged by their sound, but their look can indicate quality too. The decorative inlay on an instrument can be important to a luthier's reputation.

  
  
• Next Lynn focuses on the decorative figure portions of the inlay. He copies a template pattern (figure O) onto various decorative shells, and cuts out the shapes using a jeweler's saw. He also cuts the rest of the pattern's material and traces the entire shape onto the peg head.

• Using a rotary tool, he cuts away a channel to embed the pattern. He then places the cut inlays into the channels (figure P). His experience with inlay usually guarantees a perfect fit for the design but his epoxy mixture fills any gaps.

• After sanding away the dry mix Lynn is left with a peg head featuring a beautiful inlay pattern (figure Q). For those who admire quality instruments, this is a striking example of fine workmanship.

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