How To Make a Compact Alcohol Stove
for Backpacking or Emergency Use
I've made a couple different kinds of alcohol stoves and have been really pleased with their utility, packability, and overall efficiency. You can literally make one for less than a dollar, and the fuel for a weekend trip costs even less.
There are a lot of good pre-manufactured non-alcohol backpacking stoves available on the market, such as the white-gas burning MSR Whisperlite, or butane-burning models. These stoves are usually very reliable and have a high BTU output and it's great to have one on a backpacking trip. But they can fail due to poor maintenance, breakage, or fuel issues, and it's nice to have an alcohol stove as a backup. Having a second stove also allows you to cook with more than one pot at a time. You could certainly rely on an alcohol stove for a group of two or three people for a few days, but in my experience a compact alcohol stove works best as a secondary unit.
The homemade alcohol stove shown below generates a flame like a Sterno or a Bunson Burner. It's made from a recycled, eight-ounce paint can, a small piece of 1/32" thick sheet aluminum, a hose clamp and cotton balls.
Recycled Paint Can Model
This model is ugly and low-tech, but it's very reliable, durable, and easy to make. You will be dealing with sharp edges and fumes during construction, and an actual fire when you're done making it, so take all necessary safety precautions.
Clean the inside of an empty 8 oz. paint can with thinner or the appropriate solvent (do so in a well ventilated area) and allow it time to dry thoroughly. Remove any paper labels from the exterior. To make the collapsible pot stand, measure the circumference of the can, then use tin snips to cut a 2.25" wide strip of 1/32" thick sheet aluminum to a length about a 1/2" short of the circumference, which is about 8.75" inches on the can I used.
Cut V-shaped notches into the top of the strip of aluminum that will serve as the pot stand, and drill 1/16" holes at the top of each peak and about 1/2" apart around the bottom of the strip. This stove needs good ventilation to work properly, so yes, all those holes are necessary. When done, roll the strip by hand around the can to form a circle (careful - sharp edges - you may want to wear gloves), then slide a 12" long hose clamp over the strip. Hand-tighten the hose clamp so it forms the pot stand around the can. Stuff the can with cotton balls (real cotton - not synthetic) until it's spongy-firm. It takes four or five layers of cotton balls to fill the can.
See this website for recommended types of alcohol and their burn rates. Pour approximately three ounces of alcohol over the cotton balls, or enough to make sure the top layer is clearly soaked all around. Cap the bottle of alcohol and move it far away from the stove.
For your ignition test, find a safe place outdoors away from other flammable materials. Light the alcohol-soaked cotton balls at arms length with a stick lighter or a wooden match. Expect a "whoosh" of flame. Alcohol flames can be hard to see depending on light conditions, so be extra careful when checking it.
When you're done with the fire, simply drop the lid back on the top of the can and the flame will extinguish in a few seconds. Let it cool to the touch before packing, and replace the lid tightly to avoid spillage or evaporation of the alcohol. You'll want to experiment on your own, but I find that three ounces of fuel provides a good 15 minutes of cooking time.
This little stove works really well for frying fish or eggs, or simmering soups, but it takes 10+ minutes to boil a liter of water, depending on the ambient temperature. On the trips where I've used it there has also been a high-output camp stove available - such as an MSR Whisperlite - which boils a liter of water inside of five minutes and is preferable for that task. But a Whisperlite often produces too much heat for pan frying or simmering, even on its lowest setting.
You can raise or lower the pot stand to hold a pot or skillet above the flame. Loosen the hose clamp, raise the stand, then tighten the clamp to the point that friction holds it in place enough to bear the weight of your pot or skillet. The stand is sturdy, but be reasonable: I wouldn't expect it to safely hold a pot weighing more than 2 lbs. Heavier pots are also more top-heavy and more likely to tip the stove over. The stove must be placed an a hard, completely level surface when in use. When you're done cooking loosen the hose clamp and slide the pot stand down around the can so it doesn't protrude beyond the top of the can. I place mine in a plastic bag along with the foil windscreen while transporting.
I made the windscreen by doubling up a couple sheets of regular household aluminum foil. The wind screen looks crappy but it definitely helps trap heat. Those same crinkly sheets have survived at least seven backpacking trips, and replacing them would cost just pennies.
There are some very inventive variations on the paint can alcohol stove. Just Google "paint can alcohol stove" for even more.
And now for a more aesthetically pleasing and seemingly high-tech homemade alcohol stove....
Recycled Aluminum Beverage Can Model
This model is so easy to make it's just silly. But first, I have to give credit where credit is due: I learned how to make it from a Vimeo video from Tomsbiketrip.com. I won't provide any instructions here since they're in the video. However, my own construction tips and test notes follow.
This model actually "jets" by vaporizing the fuel inside the can and running it up the crimped "combustion chambers." In my test it boiled 750ml of water in about five minutes at 70ºF ambient air temperature. I also tested it outdoors during the winter on a 30ºF, non-windy day, using a two-quart kettle (1.9 liters) filled with cold water. It took 18 minutes to bring to a boil and required about one inch of alcohol fuel in the stove (approximately three fluid ounces or 90ml). As small as it is, the stove was fairly stable with either the 750ml or two-quart kettles on top, but I was very careful about finding level, stable and non-flammable surfaces to set the stove on. Both outdoor tests were done on flat rocks, on the ground, with no flammable materials nearby. This is very important: if the stove does tip while it's lit, the alcohol fuel will spill and spread flames quickly. It's a good idea to have some water nearby to quickly extinguish any accidental spills.
It took me about half an hour to make my first can stove, then I tweaked and played with it for a while and figured out a couple things not mentioned in the video. The craftsman in the video, Armen, says to make sure you don't crimp the top of the combustion chambers as much as you crimp the bottom, and that's right. But you still need to have a good crimp up top to get a good jet. I also learned by trial and error that while burning, the level of alcohol in the bottom of the can needs to be higher than the bottom of the combustion chambers or the jets can't draw from the fuel pool.
While this model is easy to make, super lightweight and creates a high-heat jetting action, it is not as durable as the paint can model. The beverage can model is crushable and needs a protective container while transporting in a pack, but as shown in the video that can be as simple as a used margarine tub, or you can stow it inside a small pot.
I'm wondering about the life expectancy of an aluminum beverage can that's repeatedly set alight. The one shown above has about two hours of burn time and so far shows no significant deterioration other than the paint burning off near the jets. Of course, even if I only get two or three safe uses out of it, I can always make another one.
I plan on updating this Tackk as I field test this stove, so check back later on!