Every year, I wait. After a season of gray skies and snow, and another of stormy skies and heavy rain, we are finally gifted with a blue sky, and a bright sun. I soak up every last ray on trips to the lake, sprawled in chairs on the deck, and on the dusty paths through the local fairgrounds. I revel in how the beams sparkle through dew drops and give us beautiful rainbows to make up for an afternoon shower. The sun doesn’t last long here, so I celebrate its every moment. This year I celebrated the sun in a new way. My daughter and I decided we would build a sun oven. I can’t lie, our reasons were purely selfish. We wanted cookies, but didn’t want to heat up the entire house. If cookies aren’t reason enough to build a solar oven, what is?
DIY Solar Oven Supplies List:
- Heavy cardboard
- Scissors or a box cutter
- Foam paint brush
- Aluminum foil
- Flat black spray paint (non toxic when dry)
- Small sheet of glass
How to Build a Solar Oven
We decided to build our solar oven from cardboard. Our first plan was to build one from wood that could be used from year to year, but we wanted to use what we had available. Luckily we had some nice, thick cardboard that would give us at least a full season’s worth of use. This kept our solar oven light and easily portable, even by a six-year-old’s standards.
Building the Base of the Sun Oven
First, we cut our cardboard into a 12.5″ x 12.5″ box, about 8″ deep. I folded the edges over 1/2″, glued the sides together, and waited for them to dry. I also secured the edges with staples, to help keep the box more stable. The size of the boxes can vary, based on the size of pot or pan you intend to use. This is the perfect size for us to fit one of my mini cookie sheets, but also just large enough to fit my medium-sized cooking pot.
You know, in case we get ambitious.
Next, we built a 14.5″ x 14.5″ box, also 8″ deep, from our cardboard. Again, we folded the edges over, glued those sides together, stapled them and waited for them to dry. After construction, our boxes measure 12″ x 12″, and 14″ x 14″.
When you are building your boxes for the sun oven, you want about 1-1/2 to 2 inches of space between them for insulation. We chose a 2″ gap.
Constructing the Lid
Next we measured and cut our sun oven lid. The lid covered both boxes, so it measured 14″ x 14″, and had a 3″ lip, similar to a shoebox lid. We measured the center of the lid to cut a hole to fit an 11″ x 8″ piece of glass. The glass came from an unused picture frame, which worked well with our measurements, and allowed us to use something that was previously just taking up space. Using the box cutter, we made our hole and then glued the glass over it.
We also stapled strips of cardboard over the corners to act as anchors for the glass. On top of this lid, we secured a cover. Our cover is a flat, 14″ x 14″ piece of cardboard that has been covered with aluminum foil on the inside. The lid fits over our box snugly, and the cover folds upward acting as a light reflector, directing sunbeams inside the oven.
Foil the Inside
Once all the glue had set up well, we moved on to gluing pieces of aluminum foil inside the boxes. The aluminum foil covers the inside of both boxes, as well as the inside of the cover. We used our glue sparingly, and applied it with a paint brush to avoid large globs, and to ensure that we maximized our coverage. We painted the piece of foil that would cover the bottom of the smaller box with flat black spray paint, and waited for it to dry before gluing it into place.
Putting it All Together
With the lid and aluminum foil dry, we nested the smaller box inside of the larger one, and tucked crumpled newspaper in the 2″ gap surrounding the smaller box. We made sure to work evenly so that the 2″ gap remained on all sides. You don’t want to pack the newspaper in, but rather tuck it around the boxes to act as insulation.
Cooking in our Sun Oven
Finally, it was time to put our creation to work. We moved the solar oven into the sunniest spot in the yard, placed on our lid, and opened the reflector cover. While the oven heated up, we put together a batch of cookie dough. We set the cookie sheet into the solar oven, replaced the lid and let the sun do the rest! In just under an hour, we had a batch of cookies to enjoy.
Cooking time in a solar oven varies greatly, so we made sure to do our baking on a day we would be outside in the garden. It was tempting to open the lid, but our patience paid off in chocolate dividends and a great afternoon of mother-daughter bonding. We are excited to start working on our permanent solar oven, replacing the cardboard with wood, and expanding our solar recipes cookbook. We have, without a doubt, made the most of the sun this season.
Mimi Mason is a homemaker, homeschooler, and micro homesteader. She chronicles her family’s experiences with sustainable living on her blog, The Simple Survivalist. When she’s not elbow deep in garden soil and bread dough, she can be found hidden behind the pages of a good book.
And, for another fun cardboard-based project, see our article on crafting your own DIY Lectern!
If you’re getting started with your own sun oven, check out these great recipes!