The gas can or oil can guitar is a funky contribution from African culture; African musicians who couldn't afford a guitar built their own from squared metal cans and whatever wood they could get their hands on. Gas can guitars are prized for their funky chic and their raw, metallic sound. Building one is not nearly as difficult as building a wood guitar, especially if you use parts salvaged from old electric and acoustic guitars.
Remove the neck from the electric guitar by unscrewing the four bolts that hold it on. Save the bolts and the bolt plate from the back of the guitar.
Wash the can thoroughly with water and an antigrease detergent; rinse and allow to dry.
Cut away the handle of the can, particularly if it is in the center of the can's top.
Decide which side of the can you want to face front. Cut a hole in the top of the can, flush with and in the center of the front edge. The side of the hole flush with the front edge should be about 2 1/4 inches wide, and the hole should be about 2 inches deep. Smooth the sharp edges with the rotary tool and the grinding attachments.
Trace four holes on one end of the the 4-inch length of maple, using a pencil and the bolt plate from the electric guitar neck as a template. Drill 1/4-inch holes at the four pencil marks. Repeat this process with the other side of the wood.
Screw the guitar neck bolts through four of the holes in the 4-inch length of maple, and into the back of the guitar neck.
Slide one end of the 13-inch length of maple between the fingerboard of the guitar neck and the piece of wood bolted onto it. Make sure the maple is lined up straight with the neck, and trace the four remaining holes in the 4-inch length onto the end of the 13-inch length of wood. Drill 1/4-inch holes at the pencil marks.
Turn the neck assembly over so the fingerboard is facing up. Bolt the 13-inch length of maple onto the neck assembly by inserting four bolts through the holes in the end of it, then through the four open holes in the 4-inch length of maple. Attach with hex nuts and tighten so that the bolt heads are flush with the front of the wood.
Insert the neck assembly into the hole in the top front of the can. The fingerboard should go outside the can, and the 13-inch length of maple should be flat against the inside surface of the front of the can. Use the carpenter's square to make sure the neck is at a right angle to the upper edge of the can, then drill two 3/32-inch holes through the front of the can and into the wood behind it. The first hole should be just under the bottom edge of the fingerboard, and the second should be about 2 inches up from the bottom of the can. Insert wood screws into these holes and tighten them.
Attach the tailpiece by driving three screws through the holes in the short angled section of the bridge, through the bottom of the oil can and into the wood of the neck assembly.
Shape the piece of ebony into a triangular wedge 1/2 inch across the bottom and 1/2 inch high at the peak. This will be the bridge. File six small slots into the peak of the bridge to hold the strings; the slots should start at 1 1/8 inch from each end of the bridge and be spaced about 1/2 inch apart.
Measure the distance on the guitar neck from the bottom edge of the nut (the white part under the head that holds the strings) and the 12th fret. Measure this same distance from the 12th fret down toward the tail piece. Place the bridge at this point on the top of the can.
String the guitar by running each string through the hole in the tailpiece, over a slot on the bridge, over a slot on the nut, and into the hole in the soundpost of a tuning machine.
You can get more sound out of your gas can guitar by cutting round or f-shaped holes on either side of the front of the can, toward the top. Make sure the neck assembly is bolted tight; any looseness will result in the strings being too high over the fretboard. You can check the position of the bridge by playing any string open, and then fingered at the 12th fret. The two notes should be exactly one octave apart; if they're not, slide the bridge slightly forward or back to get the correct interval.
Use a hard wood such as maple or hickory to extend the neck through the body of the gas can. Softer woods such as pine will warp under the string tension. Make sure to grind any sharp edges smooth; raw cut metal sheeting like that used in gas and oil cans can cause nasty cuts.