Tenor Guitar and 'Ukulele Necks

I built 2 tenor guitar necks with the same process as I use for tenor 'ukuleles that have a Spanish Heel joint to the body.

This is not a typical construction method that I have found online, so I am kinda hoping for the best. The tenor guitar necks will also have a one-way truss rod installed for future neck adjustments.

*** Note about neck joints....... on steel string instruments, the most common neck joint to the body would be either a dovetail, mortise and tenon or bolt-on attachment.

The Spanish heel joint is commonly found on classical guitars with nylon strings, hence, my "hoping for the best" result.

I chose this method because this is the only method I have used in the past....  The third tenor guitar I build will have a dovetail joint.

 First, I cut my stock into the following pieces;
1) Main neck
2) 2 Heel blocks that measure in hieght-3"
3) Tail block
4) 2 ears for the headstock

Using a neck scarf joint jig, I cut the main neck block at a 15° angle.

 Making sure the joint is tight I sanded the scarf joint flat.

Glued the scarf joint then the heels blocks together.

Here are the three rough shaped necks side by side.

From top to bottom
1) Philippine Mahogany
2) African Mahogany
3) African Mahogany

Tenor Guitar - Bending the sides

 Here I am prepping the side by pre-cutting to my final dimensions, at the head is 3" and the tail is 3-3/4". Also note the waist line about 9-1/4" from the head. Total length is about 23-1/2"

Using a taper jig on a table saw with auxiliary tabletop.

Here is the finished side molding jig with all-thread and star knobs.

Before the bending starts, I layout all my materials and open the side molding jig so I don't have to rush when I transfer the bent side from one jig to the next.

Materials
1) Side Bending Jig
2) Side Molding Jig
3) Heat Blanket
4) Water Bottle
5) Clamps

 

Steps
1) Plug in the heat blanket. (wait 5 minutes or so)
2) Spray some water on the blanket to see if it starts to steam.
3) Spray water on both front and back of the side piece you about to bend, then line up waist line to the middle of the waist on the side bending jig.
4) Sandwich the second mesh piece on top of the side piece and the heat blanket on the jig.
5) Turn the waist clamps down slowly.....
6) Once the waist is all the way down, bend the tail end, then head.
*** This is a fickle process that I do not rush or force the side to bend too quickly. The worst sound you can hear is cracking......
 7) Once all the clamps are secured, turn off the heat blanket and wait about 5-10 minutes.

8) Release the clamps and transfer to the side molding jig.
9) Cut the side to the center line on the side molding jig.

Repeat process for the other side.........

 Once both sides are bent and cut and in the jig, secure with clamps....

Next up..... The Neck...............

Tenor Guitar Side Bending Jig

 This tenor guitar side bending jig is modeled after the Fox Universal Side Bender knock off I use to bend 'ukuleles side.

First, transfer half the template pattern to 3 sheets of plywood and cut out the pattern outside the line. Then dram a second line underneath, about the thickness of your intended sides.

I stacked them all together, then used a rasp and files to fine tune to the second line under the main template line

Next, glue all pieces together with 2x4's spaced a little over the width of the heat blanket. The heating blanket can be purchased from Hana Lima or Luthiers Merchantile International

I cut out a wire mesh to wrapped around the top with finishing nails.

A second, mesh is used to sandwich the heat blanket and the sides together. The eye and hook bolts are used for clamping.

This board is cut into 3 pieces for the waist, front and back clamps.

,

Assembled looks like this.....

Added a few star knobs to make the clamping a little smoother.

Also, want to point out the stick at the bottom is used for clamping this jig to my work surface.

Next up, we bend........

Tenor Guitar Side Molding Jig

Here is my attempt to recreate a side mold jig I  used for 'ukulele construction and scaled to a tenor guitar size.


Draw template outline and glue end blocks.

 Rough out a few 2x4's and lay across pattern to transfer the outline to the blocks. Mark the bottom where the line touches the block, then use a square and draw a line up the side. Lay your template where the lines meet at the top of the block.

 Cut along the line you just transferred with your template and you should have something that looks like the next picture...

 Once this cut is roughed out, clean up with a file and rasp so you have 90° edges.

Next step is to add some all thread, washers and nuts to act as spreaders that clamp and expand the sides.













After this is down, I'll work on the side bending mold.....

Next project - Reproduce a 1931 Martin tenor guitar

About the Martin Tenor Guitar project.

Model# 5-17T
Serial # 46088

How to date this Martin guitar? - Visit this link

(Flashback) After taking an 'ukulele building class at the Hana Lima 'Ia School in Honolulu, HI, a buddy of mine asked if I could reproduce his fathers Martin Tenor Guitar. He said it played like a dream and thought, "hey, can you build me one?"

As a novice builder stoked to try anything I said, "Yeah sure, I can do that, no problem."

Having limited knowledge about materials, tools, time, or intricacies of building instruments, I took some measurements and started my journey...

That was 4 years ago (2010) and I am now in the midst of attempting to reproduce one of the most legendary brands in the history of guitar making with the skills I've picked up after building 8 'ukuleles. Sound, look and feel are subjective, so I'll document this process to better understand my progression in this craft of Luthiere. 

As noted above, the model number is 5-17T

5 - represents the body style 

17 - represents that it is an all Mahogany instrument.

T - represents that it is a tenor guitar

For reference, click here

Not going for an exact replica, but this repro is all Philippine Mahogany (not true Mohog, but sampling for this demo); top, back, sides, and neck. Second Tenor G, will be made with African Mahogany. Fretboard and bridge will be made of Granadillo and the second TG will be made with  Honduran Rosewood, and the nut and saddle will be made of bone with buffalo bridge pins.

Scalloped "Golden Era" forward shifted X-bracing (braces were split from an old growth Redwood 2x4) and Gotoh friction tuners. Rosette is a five layered string inlay of black and white Maple from Luthiers Merchantile International, Inc.

Here are some pics and will post more as I continue the build........ 

Step 1 - Design

  

Choose and resaw my stock.

Join and rough cut shape for top and back...

 Start the rosette with a circle cutting jig, 1/8" chisel, and some patience =)

Split the braces.....

Match up the bracing to the pattern, shape, then glue with a Go Deck and Go Bars.

 Starting the sides and neck ....... Interlude........

References:

Martinguitar.com

Hana Lima 'Ia School

Tenorguitar.com

Wood Database

Luthiers Merchantile International, Inc.

100 'Ukuleles

'Uke jigs

Jointing jig, circle jig, 15° neck scarf joint jig, and 90° fence

3° Heel slot jig, side taper jig, side clamping jig, and side holding mold







These tenor 'ukulele jigs were built to accommodate my power tools, so any jigs made by another builder would vary based on their own creativity and available materials.

Sword fish inlay 'uke complete