Flat Top Tele - Dust In The Wind

I close my eyes only for a moment, and the moment's gone

All my dreams pass before my eyes, a curiosity

In addition to this being a prototype build, I have been developing forms and learning new ways of doing things.  With so much of this project expanding my skills, there is an underlying angst with this project. One bad slip-up, and all of my work would be worth no more than sawdust in the wind. I've already had some bad results that have led to doing things other ways, and I've had some good results that have confirmed my intuition.  So, I have decided to make use of some of my practice work on the Flat Top Tele that went well, by using it to build an thin-body electric semi-solid version of the Flat Top Tele.

Yes, this project scope just got doubled in many ways, and hopefully is getting at least twice as better for it.  This will give me a chance to work through some of the body assembly issues on cheaper laminate woods before performing them on more expensive solid tone woods.  This guitar will be part Les Paul's "The Log" and part Fender Broadcaster, and built with Fender-type hardware, bolt-on neck and pre-wired electronics.

The success I had with bending the laminate sides inspired me to try making the sharp curves at the cutaway, using my steam box and a four-part bending jig.  I'll also try using my bending iron and some joinery to produce the distinct upper bout curves at the neck-to-body joint.  These also seem a lot more doable with a narrow 2-inch thin-body design.  Here is a sketch and partial parts layout of the jig for forming the sharp cutaway curves from steamed side wood.

If all goes as planned, I'll use a small interior block to splice the cutaway potion to a section that makes up the rest of the waist and the treble-side lower bout.  That's enough for now, on this warm summer evening, with This Old Guitar.

Flat Top Tele - Shipbuilding

It's just a rumor that was spread around town
A telegram or a picture postcard
Within weeks they'll be re-opening the shipyards

Some would say that bending sides of an acoustic guitar are a lot like shipbuilding, but with fewer parts, people and melodrama.  Like the underlying structure of a wooden ship, the guitar sides plus end blocks and linings are referred to as ribs.

Like building a concrete wall, it is necessary to build forms that are the negative, or outside, of the shape of the guitar sides.

Because of the complexity of the angles and curves of a guitar, as well as the tendency for bent wood to return to its unbent shape, it is common practice to use forms that sit inside of the guitar body when forming the sides, and another set of forms that sit on the outside of the guitar body when attaching the linings and the front and back panels to the sides.  Below are sketches I made while designing the form work for the Flat Top Tele.

Most modern manufacturing processes make use of CAD/CAM to produce highly accurate machines parts to close tolerances from scaled computer drawings.  With so much free information on the internet, finding a free, printable scaled drawing was quick and easy.  CAD/CAM technology is beyond the modest means at These Old Guitars at this time, so I used a tried-and-true manual method to make a tracing of the Telecaster body shape.  Starting with a full-sized plot, I applied a layer of graphite (aka pencil lead) to the rear side of the plot.  After taping the plot down, I used a stylus to transfer the outline onto a 3/4-inch MDF board.  To make it easier to see the outline on the MDF board during cutting, I drew over the pencil line free-hand with a marker.

The inner and outer forms I cut from the first MDF board served double duty as both forms and templates for the other forms.  I attached pairs of forms to each other and clamped the pairs together before shaping and sanding, so the forms would end up smooth and with matching curvatures.

I added some 2x3 blocking between the MDF side boards of the interior forms and a layer of 1x6 between the MDF side boards of the exterior form to get the proper finished form widths.  I used some wood filler on the outer forms to get a smooth, continuous surface.  Some additional parts including some PVC piping were sized and made ready, to be used to hold the bent wood against the forms.

With the inner and outer forms fully assembled, I warmed up my steam box and prepared my work areas for some wood bending.

Flat Top Tele - Thick as a Brick

So you ride yourselves over the fields
and you make all your animal deals
and your wise men don't know how it feels
to be thick as a brick.

As an art student at SUNY Binghamton during the early 1980s, I had the privilege of studying sculpture with Prof. Ed Wilson.  Wilson was well versed in many materials, including wood.  One lesson in particular I learned in that class may as well have been taught in an engineering or architectural design curriculum.  Part of the creative process of art is figuring out how to execute the piece.  So, a working knowledge of the medium is something an artist needs in order to be able to execute a vision.  In this way, this neck block is as much about how to construct and attach the layers of wood, and then attach the rest of the body and the neck to the neck block, as it is about how the assembled functions when the body is attached to the neck.  Time will if it was wise to make such a large neck block for this build.  With the top and bottom panels, this Flat Top Tele build certainly will be as thick as a brick.

Adding some temporary struts to the template made a big difference.  Cutting closer to the template outline with a jigsaw before using the router on each layer also made a big difference.  I also made sure to pay extra attention while making the cross grain cuts, being sure to hold the wood firmly against the saw table while cutting with the router.  Another change I made was to use the neck plate  pattern for the wood screws when attaching the template to each layer.  This proved to also be helpful in aligning the layers during glue-up.  The thick part of the cutaway proved to be the weakest point in this process, and I suspect this was a combination of cross grain cutting direction and the small radii.  Although I broke two of the layers during fabrication, the breaks were clean enough that I was able to repair and use them. As a result, the 1/2-inch thick top layer and one of the 3/4-inch layers have a few extra small screw holes from how I attached them to boards while making the repairs.

Before gluing the five layers to each other, I roughed out the neck pocket cutout in the top layer, and bored out the holes in the other layers for the neck bolts.  Since the body is so thick, I'm using 3-1/2-inches long, #10-32 machine bolts.  A set of #10-32 threaded brass inserts in the neck heel will receive the bolts.

When I first thought about how to glue-up the neck block,I figured I'd glue them all at the same time.  When it came time, I realized it would be easier to control the alignment of the layers and removal of squeeze-out glue by attaching just two layers at a time.  To help keep the layers aligned, I made a clamping jig from some scrap wood.  Since I had already made the rough neck pocket cutout from the top layer, it did not have neck bolt holes to help with the alignment.  So, I clamped directly against the outer surfaces of the layers to align them against the jig, and added bar quick-clamps to hold the layers flat against each other and the jig.

After the glue had dried and clearing off some excess glue, I moved on to adding the third layer.  Since I could now use the neck bolts for alignment, I trimmed the size of the jig, making it possible to use more clamps to hold the layers flat against each other and the jig.  Here's a picture of one of the layers with glue on it just before clamping.

The rest of the layers glued up without any surprises.

All ready for some work with some files and sand paper, I stopped work on the neck block assembly a few days ago, taking a break from an early summer 2014 heatwave that was gripping the east coast. This was the perfect time to get caught up on some things in air-conditioned comfort, such as accounting at These Old Guitars, and creating a company website with my long-time guitar-playing friend and website designer.  It was also a good time to put a little more thought into some of the processes I would use for the bent wood portions of this old hollow Tele body, as well as final design of her internal bracing and some forms for assembling her body.  There was also some more electrical control design work to be done with the help of long-time guitar-playing friend and electrical engineer on that LeSpork Bass project...

Flat Top Tele - Great Indoors

So go unlock the door
And find what you are here for
Leave the great indoors
The great indoors

In designing the neck block, there were a few means and methods I considered.  Flat top acoustic guitar neck blocks are typically made from a piece of lumber with the grain oriented from top to bottom panel, perpendicular to the direction of the strings.  A dovetail joint with some glue, or a tenon joint with one or more bolts through the joint, counter the forces from the strings that would otherwise separate the joint.  With a solid-body electric guitar, the neck bolts attach the neck to the bottom portion of the body, and the grain of the body and neck both run parallel to the direction of the strings.  Both of these designs makes use of the strong bending direction of the "body" part of the joint.  Since there will be neck bolts attaching the neck to this guitar's body like an electric guitar, I am orienting the grain of the Flat Top Tele like a solid body Telecaster, parallel to the strings.

Early in the design process, I considered the proportions of this guitar and decided on a body side dimension of about 3-inches.  Not having access to a band saw, my design constraints include the limits of using tools currently in the shop and readily-accessible lumber dimensions.  These factors drove the decision on making the 3-inch side dimension with a build-up of layers of 1/2 x 5-1/2 inch and 3/4 x 7-1/4 inch red oak hobby boards.  The process is similar to making a glulam beam.

Keeping things as simple as possible, I choose the top layer thickness such that it would not be necessary to route the neck pocket cavity.  With the acoustic bridge and saddle I'll be using, a 1/2-inch thick top layer should produce a setup such that the neck set angle can be fine tuned by shimming the neck pocket.  To achieve the width of wood I need for the upper bout dimension, I am also building up each layer from the 5-1/2-inch and 7-1/4-inch wide boards.

To avoid any weaknesses from lining up the joints, I will use a stagger between the layers.

Here are some pictures during fit-up, clamping and sanding of two slabs formed from 7-1/4-inch wide boards.

I used a full-sized drawing to make a template of the upper bout portion of the body, to keep final shaping to a minimum.  The template is cut from a piece of the red oak with the grain in the direction perpendicular to the neck block layers, as an easy way to provide an initial straight edge to work from in shaping the layers.  Here are pictures from before and after rough cutting the template with a jigsaw.

Next came trimming and sanding of the template, and then some experimentation to determine a procedure for using a combination of tools to shape the multiple cut-out slabs.  I knew this would generate a lot of sawdust, so I set up my plunge router in a portable saw table for using some drum sanding attachments and a flush trim router bit in the Great Outdoors.

I used a few screws to attached the template to an excess piece of red oak.  After getting used to handling the setup to minimize kickback working with and perpendicular to the grain, I had some initial success shaping the outside curves of the upper bouts and cutaway.  Hoping to complete the shape of the template with this practice piece, I began shaping the inside curves.  While working cross-grain on the inner curve of the bass side, the wood chattered in my hands and shook out of control.  In the blink of an eye, I had broken a piece off of the practice piece and had damaged the template.  I moved on to the inside curve of the cut out, with a much firmer grip, and similar results.

It was clear that using the router this way would not produce acceptable results.  Plan B calls for a few more steps and will make use of other means and methods for making the tricky cross grain inner-curve cuts.  The improved template will have extra portions joining the upper bout curves to the central portion of the neck block slabs.  This will provide stability as well as a convenient way to check alignment of the pieces during shaping and assembly.  I'll use the router to cut the outside curves, and I'll use the router and/or a combination flat drill bits, straight saws and drum sanders to cut and trim the inner curves.  I'll hold off on removing the extra portions of the neck block, until after gluing together and belt sanding all of the layers smooth, and just before attaching the bent-sides portion of the body to the neck block.

With so much design and building effort going into making this large neck block, I began considering an Ovation soundhole design that would showcase all of this craftsmanship.  I found some replacement parts on eBay and started visualizing the finished guitar in the comfort of the Great Indoors...