Sunday, April 22, 2012

Raised Copper Bowl

My friend Melanie commissioned me to do a large copper bowl after seeing the lampshades I made earlier.  With no further instructions than "I want a giant copper bowl," I was able to work without restrictions or a real plan, something that is nice when you are exploring formally.  I ordered a 18" disk of 18 gauge copper off Metalliferous and got started. 

I decided I wanted to try and raise the bowl through crimping, which is a little faster and establishes a good angle to start with, but it's pretty tough banging out those wrinkles.

To raise a bowl you create a wave, or a wrinkle in the center of the metal and force it out to the edges.  This compress the metal on the edge and stretches the metal on in the center, giving you a very controlled indentation.  Each successive raising or course raises the sides of the bowl a couple of degrees, then must be repeated.  I required some 8 courses to  achieve my final goal, and with each one taking 1-2 hours that's where most of the time goes.

The bowl nearing completion as far as shape.  I then planish the surface of the metal, which regulates the metal, removing most of the dents and bumps and giving it a texture of thousands of tiny hammer marks.  After that I rolled the edge and finished the surface with steel wool before sealing it with Renaissance wax.

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