How I built a wick style alcohol stove from two empty soda cans.
Build and use a homemade stove at your own risk. The flame from pure alcohol is not visible in day light. Use caution and common sense when experimenting with these stoves. You ARE playing with fire. These stove can “pop” when they are first lit. Pure alcohol will pop more than rubbing alcohol. A long match or long grill lighter are the best things to use until you get used to lighting your stove.
On my time hiking the Appellation Trail I saw new hikers abandon expensive gear on the trail because they realized the importance of light weight gear. You can’t get much lighter or cheaper than these home made cook stoves. Many campers or hikers prefer the penny stoves that have jets to produce the flame. They work well on pure alcohol, but they don’t run on common, inexpensive 70% rubbing alcohol. A wick stove can burn both types of alcohol. Stay away from the dollar store alcohol that is only 50% pure.
Many things can be used for the wicks. I have used everything from cotton clothesline string to fiberglass batting. I like using small 1/8″ or 3/16″ fiberglass rope. You can get some from a wood stove stove or McMaster-Carr. The fiberglass holds up better to the heat than other material in my opinion.
The first step in making a wick stove is to drill a few 3/16″ to 1/4″ holes in the bottom of the soda can. Drill a fill hole near the center and drill two additional holes for each wick that you wish to install. I started experimenting with one larger wick, but I think two smaller ones worked better. There’s no need to measure out the locations for the holes. Just do your best to “eye ball” it and drill the holes. Once the 5 holes are drilled you will need a way to cut a clean, straight line around the can. Some of the pricier stoves are cut on a lathe, but you can get acceptable results by placing a large book on a flat surface and inserting a new razor blade into the book. Place the razor into the book at the height that you want to cut the can, leaving only a small corner of the blade exposed. Push down on the book with one hand while lightly pushing the soda can against the blade and turning the can. Be sure to hold the can flat against the work table and avoid pushing too hard against the blade. Two or three complete turns should score a nice line around the can. You do not have to cut through the can, just leave a nice, deep score line. If you “wrinkle” the can it should snap at the score line. You can use a razor knife to get past any stubborn areas. Cutting out the top of your stove is now complete. I like the bottom of the stove to be a bit shorter than the top, so I add a thin piece of cardboard to the work table and rest the can on top of the cardboard when I cut the bottom half of the stove. Some guys like to cut the bottom a bit taller and roll the edge over the top of the stove to crimp the two pieces together. You can experiment and decide which method you like best.
Sometimes the two stove halves will slide into each other easily, especially if they are different brands of soda cans. I like to put a small crimp of the top section to make it easier to insert into the bottom half. I have a HVAC smoke pipe crimper but a down spout crimper or just a pair of needle nose pliers can also do the job. The wicks can be added or replaced at anytime, but it’s easier to install your wicks before the two pieces are put together. I like to install the wicks and insert the top of the stove into the bottom with a 1/4 to a 1/2 turn of twisting motion. The twisting helps to keep the ends of the wicks from getting stuck between the two halves of the stove. Slowly push the halves together. Going too fast can split the bottom half. I like to work my way around the stove in a circular motion pushing it tighter as I go. You can also place the stove on the workbench and use a wooden or rubber hammer to tap around the stove until the two halves are seated. Some stove builders use a scrap piece of soda can as a shim to fit the two halves together without crimping the top section.
You can make the stove taller to hold more fuel for a longer burn time, but I like to keep them short and compact. I don’t intend for my stoves to cook a pot of pasta. I just want to use them for fast cooking foods like ramen noodles, instant rice, coffee or tea. Raising the wicks will increase the heat output, but increase the fuel consumption. If the stove is allowed to burn out the wicks will blacken and harden faster. Blowing out the stove and pouring the extra fuel into your fuel bottle will increase the life of the wicks. When the exposed section of the wick becomes hard or black, you can shift the wick into the stove to expose a fresh section of wick.
If I were to go through hiking I would learn to use a jet type stove and carry pure alcohol, like a yellow bottle of “HEAT” fuel additive. Jet stoves need to be preheated to run, but they don’t use wicks that need to be replaced from time to time. You can also carry more fuel per pound of heat compared to rubbing alcohol, because rubber alcohol is 1/3 water. Rubbing alcohol will blacken the bottom of your pot over time. It doesn’t burn as clean as methanol. If I was just weekend camping, day hiking or building an emergency survival kit I would carry a wick stove because they are easier to use and burn a variety of fuel. A wick stove can burn thick oils like engine oil or vegetable or waste oil during an emergency. I don’t think I would want to cook with an open pot over used motor oil, but it would give you a source of light and heat if nothing else was available to you.
Again use caution and build a stove at your own risk.