Making a folding solar oven from cardboard is simple and quick
Solar cooker is made from an old cardboard box. I taped the edges with duck tape. This is the back. On the front face the duck tape helps to attach aluminium foil . I also used rubber cement to stick the foil down. There are 2 slots cut into the lower panels.
The 2 tabs that stick out higher up fit into the slots. The top part and lower part are only connected by a short section in the middle where there is extra tape. This allows the solar oven to fold there.
The lower section of the cardboard is folded just above the slots. The protruding ends fit into the slots and hold the solar oven together.
I've seen many different experiments and designs for the simple ovens. I've even seen people using a sort of funnel made from a car window shade. The kind that people put in the front window to shade the car and reflect some of the sunlight out. They are available from the dollar stores.
I don't think the shape of the funnel is critical and many variations will work more or less.
Small black roasting pan and oven bags. These bags don't melt in the oven. They are designed for cooking. The roasting pan heats up faster if it's not thick. It should be black or very dark.
Set up of solar cooker is complete. Food is in black roasting pan, the roasting pan is in the plastic bag with some air inside. There are 3 half inch stones keeping the pot from touching the bag and makes a space under the pot. This allows warm air to circulate around the roasting pan and insulates it. The bag is closed using a metal twist tie. The solar oven is facing the sun.
As the sun moves it's good to move the set up so it faces the sun. I did this every half hour or so.
This is what I cooked in the solar oven for my first experiment. Some veggies on the bottom and meat on top, flavoured with soy sauce, salt and pepper. The sun is out but a bit hazy.
After 2 hours the food is cooked. I only left the meal out for 2 hours because the sun went away. The oven warmed up very quickly and there was soon steam and condensation in the bag as the food cooked. This made the oven bag puff up more. It went above boiling quite quickly, (within an hour.)
The sun was quite weak after the first hour. The food was cooked but I would have preferred to leave it in the oven a bit longer.
This was very successful for a half hour solar oven.
I try to be accurate and check my information, but mistakes happen, especially to me.email me if you find mistakes, I'll fix them and we'll all benefit: Christine