Solar Oven Project

When I was about 10 or 12, I built a solar food dehydrator - a white box with plastic lid and ventilation holes in the ends. The sun heated it up and the hot, moist air escaped. It worked great for slices of apple, pear, and banana that I strung on fishing line inside it. Not so good when I tried to make raisins. The grapes were too big instead of being thin slices.

At summer camp a couple years ago, some scouts used a solar oven on the beach to bake brownies in about 2 hours. It was a box painted all black to absorb the heat and had a plastic lid to let the sunshine in. It worked great and I've wanted to build one ever since.

I've had a sheet of old plexiglass in the garage for at least 4 years now.

We got some new furniture about 7 months ago and a bunch of styrofoam was used in the packing - sheets of styrofoam, not those silly little peanuts. The perfect material for insulating! That's when I decided to make a solar oven some day.

This week I finally got time to start cleaning out the garage. Not being one of my favorite jobs, I got a bit sidetracked when I saw the plexiglass and styrfoam. Even more sidetracked when I found a great cardboard box used to hold reams of paper. That was the end of the garage cleaning and start of the solar oven building.

I got a half-used can of black spray paint from the basement, a roll of packing tape, and my pocketknife.

I cut out the front of the box so sunlight could get in on the south side.
I cut the 1 inch thick styrofoam to fit inside the box on the bottom and sides. Then, just to be sure it would be ok, I sprayed some paint on a scrap piece of styrofoam - it dissolved it.

So, I cut cardboard to line the inside of the styrofoam and taped it in place. Now I have an insulated box without a front or top.

I spraypainted the entire box black, inside and out, except the outside back and bottom. The hope is that this will get more hot be soaking in the sun rays.

I cut the plexiglass to fit the top and front, sanding the edges. I taped the two pieces together at the top-front edge and slid the front piece into place. I taped around it to hold it there and I now have a clear lid that is hinged and lifts off.

Being eager to test it out, my son mixed up some chocolate chip cookie dough and we put some in a pie tin and placed it in the oven. About 90 minutes later, on a hot sunny day, it was cooked. But, when tried, it tasted like someone had sprayed paint into your mouth. :-( So, now the oven sits drying for a week and I'll give it a go again.

You can find solar oven plans all over the Internet and most of them are aluminum foil lined. I'll try the black interior for awhile and then try it with aluminum to see the difference. I'm making aluminum foil covered reflectors for the top and side to gather more sunlight into the box. And, I'm scrounging for a cooking thermometer to measure just how hot it really gets in there.

OK, so at least one person has read to here and is asking "What's this have to do with scouting anyway?" Well, it's an interesting alternative cooking method for the Cooking merit badge. And, I'm hoping the PLC will have a patrol solar cooking competition at a campout after they see this oven. Each patrol will get materials to build a small oven and see who can make Ramen noodles over 200 degrees first - or something like that. Maybe a campout where ONLY solar cooking is allowed? The teamwork, discovery, and challenge is all good.

Besides, maybe a scout will expand it into an Eagle project - making simple solar ovens for people in areas with little fuel but lots of hot sun.

Scout On