Sunday, December 26, 2010

Brass Uke

I've been working with hammered metal lately on a few of my art projects.  I really like the curves that you can get out of it and the hammering is quite therapeutic.  I'm not sure exactly where I got the idea, but one day it dawned on me that I could make a really nice  archtop guitar out of metal.  But a guitar is big and the parts are expensive, especially if you don't know if it's actually going to work.  Then I remembered that I had an old Ukulele that I made from a kit hanging around...

I never play it, so thought it would be a good candidate for upcycling.  First step, disassemble.
It was glued together, so putting the sound hole over a kettle loosened it up quite quickly.  I'm saving the neck, bridge and fingerboard.
Next I bent up a piece of copper wire in the shape that I wanted the body.  Copper wire is easy to get nice curves out of, much better than my drawing skills.

Traced it on to paper...

and then traced that on to another to get 2 identical halves, as a test.

Compared it to my favorite guitar (60's  Hoffner archtop slimline) to make sure it looked well proportioned.  The Hoffner will be the prototype for the future guitar.
I then took the original paper and traced that on to a sheet of brass.

The trick is to get the 2 halves as symmetrical as possible and back and front identical.

I then took it in to our metal shop at work and cut it out with a set of battery powered shears, punching a hole in the center.

Then a whole lot of pounding.  I like to work on a piece of pine that has a hammer divot in it with a fairly light hammer.  Make sure to mark the sides so they fit together properly since there will always be some asymmetry.

While I was pounding out the contour, it started to turn into a potato chip, so I flipped it over periodically and pounded a reverse curve around the edge.  Took about an hour for each side.  Make sure your wife is out of earshot for this step.

The next plan was to bend a piece of copper pipe for the sides and solder the whole thing together.

This did not work out well.  Without a jig it's really hard to get a smooth curve while keeping the edge a consistent thickness.

So I ended up getting a piece of oak and cutting the shape out with a jigsaw.  This worked out rather well, as I'm able to just screw the neck, back and front to the oak.  Unfortunately fall set in at this point and I got really busy with house related things (building a breezeway, draining the irrigation system, putting the garden to bed...) so I stopped taking photos.  The oak is cut out along the outline as seen above, and then I cut out the inside to make it hollow.  The sides are about 1 inch thick.

I also attached a piezo pickup to the bottom of the soundboard and an output jack.  I also stained the neck and the sides the same colour, then varnished them so they would match.

Cut some really thin dowel to hide the screws.  Stained the fretboard.

Bent up some more brass for a tailpiece.

Glued another piece of wood on to the saddle and sanded an arch. 
To get the finish I sanded the brass with a Scotchbrite pad, then used a patina to darken the whole piece.  Then sanded off the middle and applied more patina to get the sunburst effect.  Then washed and varnished the whole thing.  I highly recommend playing around with patinas.  They are a lot of fun and you can get some nice effects.  I thought about using a torch to colour it, but didn't want to soften up the metal.

Yes, but how does it sound?  Quite good surprisingly for something that was supposed to be mainly an art piece.  Something like a cross between a Uke and a banjo.   I've got really heavy acoustic guitar strings on it so it's quite loud.  Plugged in it sounds like a really small grungy electric guitar.

Many thanks to my father in law Eric for all of the good photos.