DIY Ultralight Hiking Stove
Text and images by Gus Whitby
This week’s instalment of our Open Air Camp Kitchen series brings you something a little different! Why not enjoy a hot and tasty meal on your next adventure by making your very own ultralight hiking stove?
Alcohol/methylated spirits stoves make for some of the lightest backpacking stoves and hold many advantages over other cooking systems. Whilst there are many different incarnations of the spirit stove, the design I’m going to share is a simple ‘open jet’ stove made from a single aluminium drinks can, roughly based on the brass burner of the legendary Trangia Storm Cooker. Unlike the fairly heavy brass burner used in the Trangia, this little stove is super ultralight, weighing just 10 to 15 grams! In operation, this stove is relatively efficient, very easy to use, requires no pumping / priming / pre-lighting and forms its own pot support making it an excellent option for ultralight walking adventures. For obvious reasons, these stoves are also frequently referred to as “coke can stoves”.
DISCLAIMER: this project involves sharp blades and flammable liquids and is to be undertaken at your own risk. Only ever operate hike stoves outside, or in a well ventilated location.
- Aluminium can (approx. 330ml – dent free!)
- Sharp knife and / or razor blade
- Permanent Marker
- Thick book
- Safety / Push Pin
- Fuel (Recommended: Methylated Spirits)
Step 1 – Create your burner ‘jets’
Using your pin, gently punch a ring of equal sized burner holes just below and concentric with the circular top of the can. For best results for use with methylated spirits, make between 24 – 32 holes of equal size, evenly spaced to produce a uniform flame.
Step 2 – Remove the top ‘lid’ of your can
Cutting these cans can be difficult without bending / crushing / denting the can so please take care. The cleanest way of cutting these sections out is by scoring it with a knife using light-to-moderate pressure using the pressed channel of the lid as a guide. Once you’ve made one nice clean circle, make 4-6 more passes over the same score until the section is able to be pressed out from the rest of the can.
Step 3 – Separate your can into three sections, which will form the top, base and inner wall
- Measure and mark your can in
preparation for making your cuts.
- Make a mark 20mm below the edge where the body of the can tapers into the top. The total height of this section will be approximately 35mm.
- Make a mark 20mm above the rolled edge where the body of the can meets the base. The total height of the lower section is approximately 25mm.
- Make a clean and even cut around the circumference of the can. You can make a cutting tool by placing a blade inside a book at the required height and scoring. Apply a downward force to the book to stop the sandwiched blade from shifting, whilst simultaneously applying a light-to-moderate pressure to the can as you rotate it against the blade.
- Repeat the process making multiple rotations until the can is well-scored. With light pressure applied to the score mark, you’ll find that you’ll be able to ‘split’ quite easily though you might need to coax the sections apart with your blade.
- Repeat for the other end until your can is in three distinct pieces.
- Note: The scoring technique can be difficult as it can be tricky to repeat the same score mark over the previous pass. If you’re not having much success with your scoring, you can carefully use scissors to cut the sections.
Step 4 – Create the inner wall from the centre section
In this section, we’re going to create a cylindrical inner wall that fits between the upper and lower sections of the burner and nestles between the ridges of each end. On most beverage cans, the ridges on the lid or base are of different diameters, creating a challenge when attempting to make an inner wall from a single can. This will require a little trial and error in introducing a slight taper to your inner wall to match the circumference of the upper and lower ridges.
Cut your centre can section vertically to create a strip of aluminium. Coil the band into the top section of your can and seat in the grove created where the upper lid is pressed onto the can body. Mark the band where it overlaps and use tape to temporarily hold the band in place.
Now fit this band to the lower section, seating it in the groove and adjusting it, so that the previously cylindrical band has a slight taper to it. Once you’re satisfied with the shape and have checked that it fits both the upper and lower halves of the burner, cut interlocking slits in the band so that it can be slotted together and trim each end of the new tapered inner wall by approximately 10mm so that everything fits flat and square with the upper and lower sections of the burner.
Finally, cut out some small reliefs around the bottom edge of the newly created inner wall. This will allow fuel to pass from the inner well into the outer chamber.
Step 5 – Assemble the stove
To assemble the stove, you need to slot the upper half over the lower half, trapping the inner wall in the middle. This is arguably the most difficult step as the upper and lower halves of the can are both the same diameter which makes achieving an interference fit difficult without damaging the can itself.
Tips to help:
- If you have a second can on hand, try ‘stretching’ the upper half of your burner the top of the other can. Use a small amount of washing detergent to lubricate it. Avoid pushing it too far over the second can otherwise you’ll never be able to remove it again.
- Try lightly sanding the printing/decals off the edge of the lower section of the can. The removal of this material means that the edge circumference of the lower section is ever so slightly smaller than the upper.
- Aluminium contracts at lower temperatures; try freezing the lower half and heating the upper half in boiling water to take advantage of this expansion / contraction before quickly (but carefully) assembling the stove burner. Use thick rubber gloves to prevent hot / cold burns.
Step 6 – Test drive!
If you’ve managed to get to this point, congratulations! You have yourself a stove burner, ready to test drive!
In a well-ventilated location, fill the centre well of your burner with fuel, just enough to cover the inward ‘dome’ at the base of the burner. Fuel will weep from the central well into the outer chamber so don’t be alarmed if fuel ‘disappears’ before your eyes. This amount should be enough to boil 1L of water.
Remember: alcohol/spirit flames can be almost invisible so take care when refilling or handling the stove.
Carefully light your stove. During its heating phase, you’ll note that the flame will initially only be contained to the centre well. As the fuel begins to heat up, it will produce vapour, which becomes trapped in the outside section of the stove. As the fuel begins to boil, pressurised fuel vapour is forced out of the tiny jets which are ignited by the central flame. Once all the jets are lit, your stove is at operating temperature and ready to use.
Now you’re ready to put your pot on your stove. This action also closes off the centre well of the stove, further increasing vapour pressure and thereby leading to greater efficiency and fast hot cooking.
To extinguish the flame, either let it burn until fuel is expended or quickly place an inverted cup over the stove to starve it of oxygen.
Having used this stove design exclusively whilst walking the Larapinta Trail in central Australia, here are a few additional notes and tips to help you get the most out of your design:
Whilst these stoves are crazy lightweight and simple to operate, they will not suit all adventure types (particularly in cold weather) so assess your trip and cooking requirements before commencing your journey. Consider reading our guide to hiking stoves for our thoughts on cooking solutions whilst on the trail.
If using the stove as a pot support, then due to its small footprint, limit pot size to less than 1 litre and always use on level ground.
The stove design doesn’t simmer very well so if you’re rehydrating food, consider bringing water to boil and letting your food sit in your pot inside an insulated pot cozy. Once re-hydrated, re-ignite the stove to reheat the meal. This also reduces fuel consumption otherwise expended during simmering.
Consider making a small windshield to both prevent the stove from being extinguished by wind and to trap heat. Pictured is a small conical windshield I made out of an offcut of aluminium flashing. It’s sized so that it can be coiled up and placed within the pot. Note the ventilation holes.
The printing on the can will eventually burn off, leaving you with quality patina, but if you’re so inclined, use steel wool to remove the can’s branding and print.
Whilst a variety of fuels can be used with this type of burner, I would strongly recommend using methylated spirits for fuel in the UK. Methylated spirits are inexpensive, easily sourced from a hardware store, and burn relatively cleanly compared with some of the slightly more toxic (and volatile) fuel sources.
In the example below, I’ve used Isopropyl alcohol which, whilst cheap to acquire, doesn’t burn very cleanly (as can be seen by the soot build up on the side of my pot).
Zen Stoves is a valuable resource for all things related to alcohol backpacking stoves. If you’re looking to further your understanding of ultralight alcohol stoves, it’s definitely worth a look.
Thanks for reading!