You see this a lot on YouTube, etc.: you polish the base of a pop can so it’ll serve as a parabolic mirror you can focus sunlight with to start a fire. Has anyone here actually done it? I’ve tried and at least with the suggested polishing agents (chocolate, toothpaste) I can’t get the finish shiny enough. Any suggestions what I might be doing wrong?
Any automotive polishing compound. I know corn starch is something we used to use. Ash would probably work but you need a fire to get ash. You can mix water and dirt and seperate out the fine silts by letting it settle. The fine silts might work as well.
I’ve been digging out my old Boy Scout/ camping books and trying a bunch of stuff they suggest.For instance, my Scout manual showed someone scorching a piece of cloth over an open flame to produce char cloth, used to get sparks going into a flame. Maybe that’s just possible if you’re very careful; but my experience was that any flame hot enough to char the cloth in the first place will be hot enough to set the resulting char on fire. A look online showed that almost everyone recommends using a tin with a lid to char the cloth in the absence of oxygen.
Long story short: don’t believe everything you read (or see on YouTube), and that until you actually do something, you don’t know how.
The bit about charring cloth was probably written before the widespread use of synthetics in cloth. You can char 100% cotton pretty easily. Synthetics (read “plastic”) burn or melt rather than char.
The hard part on most modern camping trips would be finding any 100% cotton cloth.
And starting a fire with a fire bow isn’t nearly as easy as it’s made out to be, either, with the main complication being that the string tends to break. Back in my Boy Scout days, we had a contest between the patrols for who could start a fire quickest that way, and my patrol eventually won… after going through two leather thongs, three shoelaces, and finally resorting to just taking turns rolling the pin between the palms of our hands.
As a tip, by the way, lint makes a very good tinder, and is the only thing I’ve ever observed to catch from any of these “primitive” firestarting methods. If you’re ever in a real survival situation, search your pockets, your belly button, and the folds of your underwear. Yes, there are other tinders that are supposed to be even better, but lots of luck finding them if you ever actually need them.
Two “duh” questions: did you make sure the spindle was on the outside of the bow, not the inside; and did you have a good enough top piece that the spindle could turn freely?
There’s no way I can remember clearly enough after all these years to answer those questions. It is quite possible that we were Doing It Wrong.
Really fine steel wool?
I too am curious to see if you can pull this off.
If you just want to get it done and not play with possible polishing compounds then I’d get something like this, metal buffing compound, often sold in kits like this.
Black Emery, Brown Tripoli (pretty much the toothpaste), White, and finally Red Jeweller’s Rouge (pmt chocolate) in that order with some kind of power rotary tool, drill or Dremel (this will turn hours of polishing into minutes). Proper buffing bits (scroll down the first link and you’ll see some hard felt buffing “cones” that will get into tight spaces). Change the bit when you change compounds!
Really too much to spend for just this job, but you’ll be set to mirror polish pretty much anything metal for a decade or so.
CMC fnord!
Les Stroud did the soda can trick on Surviorman. He used chocolate to rub the surface shiny. I can’t recall which episode.
Les has demonstrated a lot of fire starter methods. A 9V battery and steel wool. Using Ice as a magnifier. etc. but only once.
His most common method is flint and steel or the wood bow.
I carry a magnesium bar.
A ferrocerium, or much as, if not more likely, a mischmetal rod glued into a magnesium block. Many forgo the magnesium block altogether.
The magnesium is nice for bad or slightly damp tinder but the ferrocerium/mischmetal (this is the stuff used in Zippo and other “spark” reliant lighters) is enough to get a fire in better that not conditions with adequate tinder.
These types of firestarters still require a understand of the best way to use them, see: most seasons of Survivor.
CMC fnord!
Why does that sound like something sold in nutrition stores? 
If you have time to be farting around with soda cans and chocolate, then the need for fire must not be that pressing. This is one of those semi-useless tidbits that get passed around as survival lore. IME, the real difficulty in getting a fire going primitive-syle under conditions where not having one means death is finding enough usefully dry tinder and kindling quickly. Bow drills, lenses, and stuff all work but they aren’t easy and they don’t like damp tinder at all.
Personally, my preferred method is a big plastic Fresnel lens, like the kind used for full-page magnifiers. It’s lightweight, it doesn’t run out, and you can keep it on the tinder for a very long time if needed, with very little muscular effort. It does require a moderately clear day, though.
OK, an update: I couldn’t get chocolate to work at all, and regular toothpaste scratched the can too much. What I finally found that worked was gel-type toothpaste, just abrasive enough.
I agree with Scumpup though: this is a fun trick but I can’t see it as a useful survival method. You’re stranded out in the wilderness somewhere, you don’t have a matchbook, a disposable lighter, or any other way to start a fire; but in addition to a soda can you just happen to have the right abrasive (and ~3 spare hours) to polish it? Daniel F’n Boone would have used a lighter if they’d had them.
I don’t recall the soda can fire starting being presented as a survival skill anywhere. It’s always been a cool party trick. I made a firelighting soda can years back, using some sort of ages-old polishing cream.
An empty aluminum can weighs almost nothing and takes up little space. I could see carrying one in my backpack, although I prefer more ancient, organic firelighting gear and carry them, instead. Alternatively, one could polish the bottom of a full soda can, and have it both as an energy source and a backup firelighting method. Or the empty can could be loaded with prepared tinder and sealed waterproof.
Any wise survivalist carries bone-dry, prepared tinder of choice with her at all times. Stashed in a ziplock bag inside a small coat pocket, it again weighs nothing and takes up no space, but saves the day if need be.
I don’t understand this mentality. For the same weight and less money you can carry a couple of disposable lighters. As an added benefit, they start fires much better.
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Mag bars do not leak
Easy to dry off
Last longer
They really are very light for that size
It does require a better quality tinder
We out for 2 days or all winter?
The point, to what extent there is one, is to have and know how several backup ways to light a fire, especially renewable ways. Matches and lighters are short-term, once they’re gone they’re gone. Flints are intermediate, will eventually run out but good for thousands of lights. Other methods such as bow drills, fire pistons and concentrating sunlight are forever, or at least until your equipment gets lost or broken. Note that most of these methods aren’t exactly low-tech, you’re still dependent on bringing the products of an industrial civilization with you. So unless you’re expecting the collapse of civilization, or you’re planning to spend three months backpacking in the outback or the Canadian wilderness, lighters and matches will serve 99.99% of the time.