So I saw an article on how to start a fire with a soda can and a bar of chocolate, so I decided to give try it for myself to see if it works. The bottom of a soda can is ideal for reflecting and concentrating the sun’s light, just not in its present state. Apparently you can polish the bottom to a mirror finish using chocolate or toothpaste. After about an hour of polishing with chocolate I still hadn’t gotten the bottom of the can to a mirror finish, it was better just not reflective enough. I think its possible it’s just going to take quite a bit of time and rubbing. So I decided to speed things up and use some mothers aluminum polish that I had, here are the before and after results.
Once I had it all polished up I gave it a test and it worked great. You just hold your tinder over the bottom of the can and find the suns focal point just like you would with a magnifying glass. It works extremely well with char cloth and char cotton balls. Caution: You should wear sunglasses when you use this they protect the eyes and make it easier for you to find the sharpest focal point.
Now I wanted to make it more portable, so I cut off the bottom of the can with a pair of tin snips then rolled over the sharp edge using a pair of pliers (see the picture below). I’ve seen these solar fire starters sell for as high as 40 dollars, this one cost me my 5 cent refund and a few cents of aluminum polish.