Materials Needed:

• Pencils
• Large and small cardboard boxes
• Newspaper
• Cardboard (as large/larger than the top of the large cardboard box)
• Non-toxic glue
• Scissors
• Black construction paper
• Plastic wrap (or a piece of glass, as large as the top of the large cardboard box)
• Aluminum foil
• Non-toxic invisible tape (or a stapler)

1. Find two boxes. One should fit inside the other with a 2- to 3-inch space on each side.

Both boxes should still have all four of the flaps intact on the top and bottom.

2. Line the bottom of the large box with crumpled newspaper.

3. Fill the space between the sides of the two boxes with crumpled newspaper.

4. Line the sides of the inside of the smaller box with aluminum foil. You can use a non-toxic tape or fold the edges of foil over the top of the box to hold it in place.

5. Line the bottom of the inside of the smaller box with black construction paper to absorb heat.

6. Measure the distance from the outside of the small box to the inside of the large box, and folded the top flaps of the large box so that they fit this measurement.

(A side view if you could see through the sides of the box would look like this)

7. Put the smaller box inside on the crumpled newspaper (or whatever you choose to use as your insulation), and fold the small box flaps over the large box flaps

(A side view if you could see through the sides of the box would look like this)  

This gives you a double wall box with about three inches of space surrounding the inside (which is where you put the insulation, i.e. newspaper)

(Remember, because the small box will have the aluminum foil lining the insides,

it will look shiny inside, like this)

8. To make a reflector (to increase the amount of light entering the box):

• Lay a piece of cardboard on top of the large box and trace the shape of the box onto the cardboard.
• Add 2 inches around the trace line and cut out to make a reflector
• Cover the cardboard piece with aluminum foil. Smooth out any wrinkles and secure the aluminum foil to the cardboard with non-toxic glue or tape.
• Tape/Staple the reflector to the outside back of the large box.

(You may need a couple of sticks or rods to brace the reflector for proper aiming and to make sure that it does not move in the wind. Two sticks for the back of the reflector and two for the tops of the sides should suffice under normal conditions)

9. Situate the oven with the box opening up and the reflector facing the sun for maximum heat.  

10. Place food to be cooked in the solar oven.

11. Stretch clear plastic wrap (or place a piece of glass) across the top of the large box.

Secure the plastic (or glass) with tape around the entire box.

Tips:

1. Cooking time is about twice as long as in a conventional oven.

2. Preheating takes about 30 minutes.

3. Use bigger boxes for a larger oven.