This one was super simple and easy - The basic idea is just one box inside another box, with insulation in between and something shiny to reflect light back inside and something clear to keep the heat in.
I spray painted both boxes black to help absorb more heat. The inside box is lined with tin foil on the inside (shiny side out) to reflect as much heat to the food as possible. I used a towel and an old t-shirt to insulate between the boxes. To insulate between the bottom of the inside box and the outside box, I just shredded some pieces of cardboard and some foam packaging that was lying around, and set the inside box on top of that.
The mirror came out of a big, rear-reflecting TV I scavenged. These things have lots of awesome optical parts for burning and melting stuff. :D I reposition the mirror every few hours to shine extra light into the box.
The cover was part of the screen from the TV. Once I realized the cooker was actually going to work, I cut it down to size. Any clear plastic or piece of glass would work.
And that's pretty much it... electricity-free, crock-pot quality cooking (as long as the sun is shining, that is). For my next project I want to build a rocket stove for cloudy, dark and cold days.
