Here's some pics of my progress so far.
Originally I wanted to build a 2x3x5 oven, but the cost of sheetmetal was too high.
What I ended up doing was buying an old metal filing cabinet from a recycler. It wasn't as large as I wanted, but with an internal size of 18" x 36" x 40" it should do most any parts I need.
$40 got me the cabinet from the recycler.
Here's a pic of the cabinet after I stripped everything out of it. 1 nice thing about using a filing cabinet is that it already has rails you can use for shelving and hanging parts:
