Tuesday, July 8, 2014

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.

Monday, July 7, 2014

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.