Michael Bradley: Independent Study - Guitar

Design:  the design of this project is sourced from several places.  I decided to make a semi-hollow body, or chambered, electric guitar.  The original sketches were made by my younger brother, and I brought those to life using references such as a Fender Stratocaster electric guitar, and a Gibson Arch-top Semi-hollow body electric guitar.  The finish was supposed to be a red and black sunburst, as is common on many guitars, however the end result is somewhat of a rustic rose color with more of a natural fade to black, instead of a well defined line between the two colors.  The sound holes on the top of the guitar are made using the shape of the guitar itself as a reference, splicing together curves from each side of the guitar. A lot of research was done into constructing and finishing electric guitars.

Reference 1 - Strat

Reference 2 - Archtop

Reference 3 - Sunburst Finish

Techniques: The design was created entirely using curves.  Some specific dimensions were found online and translated to rhino, but for the most part, the shape was created using rounded curves.  After deciding on the final exterior shape, I created a large interior chamber, leaving room for all of the electronics, and the bridge.  Then, I created a chamber for the electronics themselves.  I created a third closed chamber to decrease weight, and add treble resonance to the body.  I "fishboned" the chambers, or rather, made them encroach in between the pickups to increase any possible resonance from the strings.  I left space for the future addition of strap pegs at the bottom, and top left of the body.  After creating my shapes, I decided on a thickness, and then duplicated the curves on vertically until I had as many layers as I wanted, each with the correct combination of curves.  I only extruded the curves to see what the shape would look like.

Techniques 1 - Basic Curves

Techniques 2 - Final curve layers

Techniques 3 - Extruded model

Techniques 4 - Cutsheet Layout

Construction: After cutting out all of the slices, the interior slices out of regular birch plywood, and the top/back out of nicer Baltic Birch plywood I glued them in the correct order, one at a time, with clamps placed around the edges. Once glued, I test fitted the neck and found the approximate location of the bridge to drill mounting holes. 
     Next I tested some dyes on scrap wood, and after deciding what to do, I sanded the entire guitar to 400 grit, which was especially difficult on the sides which had not glued perfectly even.  After sanding, I rubbed in black dye, let it dry, and then sanded the whole thing evenly back to 400, because water based dyes raise the grain of the wood back up.  I sanded more in the middle of the top than the sides, so that I could add red later.  After 5 or so repetitions of this process, and getting the wood as dark as I wanted, I added 5, which took another 5 or so coats. As a side note, this took a whole afternoon of dying and sanding, etc, and then when I got home I still wasn't happy with the red, so I did another 3 or so coats till I was somewhat happy.
     After the final sanding, I put about 3 cans of Lacquer onto each side of the guitar, with a day waiting in-between sides.  The lacquer takes about a month to cure, but since I didn't have that long, I waited about 1 week before polishing it up.  It was already pretty shiny, but the lacquer drys with an orange peel effect, so I again sanded the whole thing to 400 grit, this time wet, then all the way up to 1,500 grit, and then polished it with both a rubbing compound and polishing compound until it was nice and shiny, and flat.  Finally, I added all the electronics, assembled the neck, put strings on it, and did some final adjustments. 

Construction 1 - laser cut

Construction 2 - Glued, front

Construction 3 - Glued, back

Construction 4 - Test fit neck

Construction 5 - Lacquer, front

Construction 6 - Lacquer, back

Construction 7 - Wet sanding before polish

Materials: I used the following materials for constructing the body, not including the additional hardware like pickups, strings, etc.

Lots of sandpaper (100, 220, 400, 1000, 1500 grit)
Lots of titebond glue
6 cans of Deft High gloss Lacquer
1 sheet of baltic birch plywood (From wood world)
2 sheets of regular birch plywood (From home depot)
1 bottle black fabric dye
1 bottle red fabric dye
1 old tshirt, cut up for rubbing dye and cleaning
Rubbing compound
Polish paste
a couple screws for the access panel on the back. 

Final 1  (doesn't do the gloss justice)

More final images soon