If you use rugged solar foil to create the reflective surface, you can glue it to the 2 x 12s and the plywood base prior to assembly. If you are using heavy-duty aluminum foil, which tears easily, you’ll get better results if you glue it to the wood surfaces after the box is assembled.
Cooking with a Solar Cooker
Anything that can be cooked in a slow cooker, including meat, can be cooked in a solar cooker (as long as the sun is out!). You can also make bread and other baked goods, rice, fish, potatoes, and dozens of other dishes. You’ll need to experiment a little with a cooking thermometer, because cooking times will vary depending on the time of year and where you live; most foods will need 2 to 4 hours. Other points to keep in mind when cooking in a solar oven:
• Be sure to adjust the back leg so there are no shadows in the cooker, and move the cooker every hour or so to face the sun directly.
• Since the cooking temperature is fairly low and the food is in a closed pot, it won’t overcook or dry out if you leave it in too long.
• You can use a candy thermometer or oven thermometer to find out how hot the oven is. This will help you determine cooking time.
• Avoid opening the lid unless absolutely necessary— it’s estimated that every time you open the lid you add 15 minutes to the cooking time.
• Wipe down the interior of the oven after every usage. Keeping the glass lid clean allows as much sunlight in as possible.
• You cannot cook in the oven without a dark pot with a lid. The dark metal of the pot is warmed by the sunlight and transfers its heat to the food.
• See the Resources section (page 152) for links to sites with solar cooking recipes.
• Do not allow children to use the solar oven unless they are under direct adult supervision.
Getting a Handle on Glass
Since it is virtually impossible to lift the glass lid from above, you’ll need to install handles or pulls designed to attach to glass (available from woodworking hardware suppliers) to lift and replace the glass cover. The simplest of these (see Resources, page 152) require no drilling. You squeeze a bead of clear, 100% silicone into the U-channel of the lid handle, then slide the handle over the edge of the glass.