Aluminum Cans Uses for Preppers

We’ve all been walking in the pristine wilderness and suddenly we see that someone left their beer cans lying around. Some of my hiking partners have uttered some pretty coarse profanities at the “modern barbarians” who left a pile of their aluminum cans for someone else to clean up. And I must admit that litter of any sort bothers me. After all, shouldn’t we all adhere to the rule of “If you packed it in, pack it out”? Aluminum cans are also so light and can be crushed so easily that they don’t take up a lot of space on the hike out.

Don’t litter! Period. OK, now that I’ve gotten that out of my system, here’s another perspective.

An aluminum can is another of those multi-purpose objects that can literally be a life-saver if you’re lost or stranded.

With an aluminum can – and a bit of skill and your Swiss Army knife – you can make a fire, purify water, cook, signal, and do a few other things! That makes the discarded aluminum can a “multi-purpose tool.”

Let’s take a look at the many uses of an aluminum can that you happen to find.


I was a bit skeptical when I first heard about making a fire using the bottom of an aluminum beer or soda can, but it actually works. Well, it works if you prepare the can properly and if you have a LOT of patience. The very bottom of an aluminum can is not a true parabolic dish, but when highly polished, it can be used to focus the sun’s rays to a point and ignite tinder.


Because the surface of the bottom of the aluminum can is not polished, you need to give it a high polish in order for it to sufficiently focus the sun’s rays. When I first heard about this, people were suggesting that you should polish the bottom of the can with chocolate, a suggestion that I have never fully understood to this day. Maybe that suggestion was made because a hike is likely to have some chocolate in the back, but it is clearly not the best way to polish the can. The best polishing agent I’ve found for this is fine steel wool. However, it’s always good to know several ways to do each task, and if you don’t have steel wool, try toothpaste.

Polish the bottom of the can for about 10 minutes, until you have an obviously-bright and highly reflective surface. Once the bottom of the can has the high polish, you are ready to make fire.

Experimenter Eric Zammit of Altadena discovered by practice that he could quickly get coal if he had polished the bottom of the can with the finest steel wool [0000] for about 10 minutes. Then, using a small bit of rolled-up mugwort for tinder, he would have it smoking within 3 seconds, and he had a lump of coal within 10 seconds.

Point the bottom of the can towards the sun, and then move your tinder into the bottom area, watching for the point where the light focusses to a point. When you find that point, keep your tinder there until you get your coal. This is akin to making a fire with a magnifying glass, except you are not focusing the light through the lens, but rather you are focusing the light back up to a single point.

Related: What Is The Best Way To Store Water For SHTF?


One of the most important skills in the back-country is the ability to purify your water. If you’re just out for the day without all your normal equipment, you might not have a water filter or purification pills. So just fill the aluminum can with your suspect water, and boil it over a fire. Boiling will kill any of the biological contaminants that might make you sick.
If the water has stuff in it, then, by all means, pour the water through a cloth first.


You can also take the top off the can and use it as a small coffee pot or soup pot. Just punch two holes in the rim at the top so you can add a wire and suspend it over the fire.
Even if you don’t have your Swiss army knife for cutting the top off the can, aluminum is so soft that you could actually use a sharpened stick or stone for this job.


If for some reason, you can’t get a fire going, or if a fire would reveal your whereabouts, you can use that aluminum can for a makeshift water filter. You will punch little holes into the bottom of the can, and you will cut off the top of the can. A variety of filter materials have been tested, such as packing the can with clean socks.

In experiments that were done in Great Britain by Stefan Kallman in the 1980s, he found that he could create a reasonable water filter with an old aluminum can. He cut off the top of the can, punched holes in the bottom, and added sphagnum moss to the bottom. Then he filled the bulk with the can with a blend of charcoal, peat, and more sphagnum. He added a thin layer of small pebbles to the top. These were ingredients that would be available in the UK, but not necessarily everywhere.

Other filters could be clean sand, mixed with a bit of charcoal, or the already-mentioned clean socks (or other fabric that can be packed into the can).

A filter like this cannot be expected to be 100% effective, but it can help to remove some contaminants from the water.


I have seen several versions of candle lanterns using a beer can, but the easiest is to simply cut two “doors” into the can, and set the candle into the can securely with a bit of hot wax. You then use the tab on the top to hang the lantern wherever you want it. The doors can be adjusted so that the light reflects where you want it, and to help protect the candle from the wind.

Another version is to punch a hole in the bottom and push a regular candle through that hole. As it burns, you periodically push it upwards.

Related: How To Turn Bacon Grease Into Emergency Candles


It’s easy to make an emergency signaling mirror from an aluminum can. Just cut a circle or a square from the can. Aluminum is soft and you can do this with the scissors on your Swiss army knife, or with any knife.

If you’ve ever used a regular signaling mirror, you know that it helps to have a little hole in the middle of the mirror to sight through. Cut a small hole in a rectangle of the aluminum through which you will attempt to observe your intended target. If the sun is in the ideal spot in the sky, and if the person flying overhead happens to be looking your
way, perhaps someone will notice your signal mirror and hopefully, someone will respond appropriately. Who knows?

Your makeshift signaling mirror from the side of a beer can needn’t be round, but I would at least round off the edges of a rectangle so you’re not holding a piece of metal that might cut your hand.


A little whistle can be made from two rectangular pieces of an aluminum can.
Each piece should be about ½ to ¼ inch wide, with one piece about an inch long and the other about 2 ½ inches long. Place the shorter piece over the long piece, like a cross, and then fold the horizontal piece backward onto the longer piece. Then fold the top of the long vertical piece back over the wrapper you just made. You’ve now created the little slot through which you blow for a whistle. Fold up the lower flap so that the entire piece looks like the letter P from a side view. (Yeah, it sounds complicated, so study the pictures. It’s actually very simple.) Make sure the little opening is big enough to blow through, and then tweak it until it works.

If you practice with this a bit, you might create a functional whistle. On the other hand, acorn caps and grass blades also make serviceable whistles. The sound of the whistle travels much further than the human voice and this can be a lifesaver in an emergency. You knew you should include a whistle in your survival kit, but you didn’t. Now is the time to improvise.


You’re lost with nothing, but there’s an aluminum can. You can cut a piece of the aluminum and write a note on it for other people to read. You don’t need a pencil — just find a thin stick to carve your letters into the aluminum. Then hang it in a prominent place for others to see whatever you need to communicate. The piece of aluminum will be shiny and will be more obvious than a paper note which might get blown away, or rained on. This is akin to the aluminum tags that gardeners use to mark their trees and other plants.

Related: 5-Minutes DIY Tested Faraday Cage Out Of A Trash Can


A slice of the aluminum can be made into a shim for picking a combination lock. Yes, I know that picking a lock may not be the top of your priority list when lost or stuck somewhere, but it does have its place.

To be fair, I have only had mixed results with this. If you’re interested in the art of locksmithing, you would do well to take a course and learn all about locks. I learned about this technique from Neil Strauss’ “Emergency” book. It works with most combination locks, but apparently not all, possibly because of the quality of the lock, or the thickness of the aluminum. It would take a lot of space for me to describe the shim that you would make, and how to use it, and tweak it, so I suggest you just search for this on Youtube.


You take the little snap-up thingee, and with a metal clipper, you turn one loop into a hook. Sharpen it a bit, and add it to your line. Soon you’ll have dinner!

Originally posted 2019-06-19 01:18:37.