Want to try a new way to cook your food out in the wild using the beauty of solar energy? Now you can make your own Fresnel lens.
Putting the Fresnel lens and frame together
If you’re unfamiliar with the Fresnel lens, imagine a giant magnifying glass. You can start a small fire by directing sunlight through the magnifying glass onto a tiny pile of wood shavings or paper. Now imagine that magnifying glass many, many times larger and you have a Fresnel lens.
I headed over to John’s shop with my lens. I should mention, there are two types of these lenses: linear and spot lenses. Most lenses coming out of the older big screen TV’s are linear, and produce a more diffused area of heat when the sun strikes the center of the lens. If you are really lucky, you may get a spot lens. It focuses the sun into a small focal point on the lens, and you may be able to melt metal with it.
John is not just a great friend, but a great teacher. He measured and cut a length of wood for one side, and then let me do the opposite side. For the frame, we made 2 long boards, 2 shorter boards, each with a fine groove down the center of each. This way, the lens would fit snugly into the frame, and not fall out. A threaded bolt (lag bolt) was inserted halfway down the long side of each frame.
Next, we worked on making two “T” shaped legs, with the “T” being the base touching the ground. A hole was drilled about 2″from the top of each leg. The lag bolt that was sticking out of the rectangular frame, was inserted through the top of the leg. John added a small plastic knob to the outside to keep everything in its place.
Voila, it was finished! Since it was a sunny day, we experimented with it, by placing a piece of heavy cardboard on the ground, and angled the lens towards it. After several seconds, smoke began to appear. Then the cardboard began to burn. With that, I knew it could generate heat. My next step was to learn to cook with it.
If you decide to make one of these yourself, remember, SAFETY FIRST, and then have fun trying this new, solar powered wonder.
Amazing! This will definitely come in handy during your bug out. To learn more about DIY Fresnel lenses, along with tips on how to cook with them, check out Survival Mom!
Featured Image via Sarah Sammis/Flickr