He “grills out” with a homemade solar oven, which heats up to 350 degrees. This solar oven gets hot enough to bake a killer batch of scones—and in the summer, it can whip up brownies in a brownout.
By William Gurstelle
No power? No problem.
This afternoon project will let you cook off the grid with a sun-fueled oven hot enough to raise some dough.
1) Find Parts
The project makes use of scraps (or full 4 x 8 sheets) of ¾-inch and ½-inch plywood. It also requires 4d trim nails, a 6-foot length of 1½-inch-wide flat wood trim, 36 inches of ¼-inch-square molding, a half-sheet of ½-inch rigid foam insulation, a half-sheet of ½-inch drywall, two white ceramic knobs, eight 3-inch mending plates, construction adhesive, high-temperature flat black spray paint, heavy-duty aluminum foil, No. 8 bolts, washers and nuts and a piece of ¼-inch plate glass cut to 13 x 14½ inches, with the edges sanded smooth.
2) Build the Box
Construct an open-top box using ¾-inch plywood for a 14 x 15½–inch bottom. Use ½-inch plywood to make four 7-inch-tall sides. With a vise and pliers, bend the mending plates to 135-degree angles. Fasten two plates to each box side with 1-inch No. 8 bolts, washers and nuts. Cut pieces of rigid foam insulation to line the box interior. Glue the foam to the plywood using construction adhesive. Cut and glue drywall panels to fit on top of the foam. Paint the interior black.
3) Prep the Top
Nail wood trim over the edges of the foam and drywall. Cut the molding into four 9-inch lengths. Center the glass pane over the opening. Put the moldings around the glass perimeter. Nail them down to steady the pane. Glue the knobs to the glass.
4) Make Reflectors
Cut rigid foam to four 12 x 24–inch panels. Wrap the foam in aluminum foil. Bolt the panels to the plates.
5) Bake It Up
Prep food in a black enamel pot with a lid; set the pot in the box. Replace the glass. Prop up the oven at an angle so the sun and reflectors shine directly on it. Use an oven thermometer to gauge the heat.
Note: This oven does not bake as quickly as a regular one, but our scones, with butter and lingonberry jam, were still delicious. Wear oven mitts to handle the ceramic knobs—they get hot!
Re-posted from Popular Mechanics