Pepsi Can Stove

The History

The basic design dates back more than one hundred years. It consists of a double wall gas generator, a perforated burner ring, and an inner pre-heat chamber. Trangia has been selling a commercial version of the design since the 1950s, Safesport marketed a stainless steel stove in the 1990s. Interestingly the Trangia stove burner is made from brass, even though all the other associated parts that come with it are aluminum. A plastic bag is provided for the burner so that when packed away the two dissimilar metals do not develop corrosion.

In the unpressurized open-top design the double wall acts as a gas generator, transferring heat from the flame to the fuel. This effect enhances combustion, producing more heat than other passive designs. The inner wall also creates a convenient preheat chamber for starting the stove. Once the fuel has warmed up, its vapor will travel up the hollow wall, pass through the perforations, and form a ring of flame. Vapor also rises from the center of the stove, but will pass through the ring of flame for efficient combustion, as long as a pot is over the stove. Other pressurized designs aim for efficient combustion through closing off the fuel chamber after filling or filling through the gas jet holes.

The Construction

The stove is made from two aluminum can bottoms (for some reason it seems Pepsi is superior to Coke). An inner wall is cut and rolled from can material. A ring of holes is pierced into the top with a pin. Parts are glued with high-temperature epoxy or sealed with thermal foil tape. Total height is less than two inches (50 mm), though dimensions can be increased to hold more fuel or decreased to take up even less space.

The choice of aluminum has several advantages: light weight, low cost, and good thermal conductivity to aid vaporization of fuel. Alternative construction materials have been used, including stoves made of tin cans such as cat food tins, tuna cans, and juice cans-the basic design is very similar. Windscreens/stands can be fabricated from tin cans, cut to size and with ventilation holes added.

Using the Stove

Each stove is designed for one or two people. When used to cook larger meals (greater than 2 cups (0.5 l), it is less efficient than a more powerful stove that delivers more heat to a pot. This is because a longer cooking time is required, during which more heat is lost to the surroundings. A more powerful, pressurized version is shown below.

To use the stove, a small amount of fuel is poured into the stove and ignited. The pot is then placed above the stove, on a windscreen or stand. The flame is small at first, only burning from the inner chamber. Once the fuel has warmed up, requiring about one minute, its vapor will pass through the perforations and form a ring of flame. Enough heat from the flame is passed to the fuel to maintain full combustion until fuel runs out.

The stove should not be re-lit unless it is fully cooled, otherwise flare-ups or explosive combustion (in the case of a pressurized design) may occur.

Comparisons

The stove can outperform some commercial models in cold or high-altitude environments, where propane and butane canisters can fail. Ronald Mueser, in Long-Distance Hiking, surveyed hikers on the Appalachian Trail and found that this stove was the only design with a zero percent failure rate.

Fuel usage (by weight) is about fifty percent greater than a butane/propane stove. Can stoves weigh less than an ounce, compared to three ounces for the lightest gas stoves. Many commercial stoves also require special fuel canisters, adding to overall stove weight. No such canisters are necessary in a can stove; denatured alcohol can be carried in virtually any lightweight container, such as a plastic soda bottle. The weight advantage of the beverage-can stove is diminished by the greater fuel consumption (especially on longer hikes), but may still be offset by their reliability and simplicity.

Other attributes of the beverage-can stove are its nearly silent operation and suitability as an emergency backup. Denatured alcohol is a relatively environmentally friendly fuel that doesn't leave soot, though it is toxic to drink. (Pure ethanol is rarely used as stove fuel, since it is usually subject to liquor tax.) Denatured alcohol is commonly available at camping outfitters and hardware stores. These stoves operate well on 90% isopropyl alcohol, marginally on 70% and not at all with 50%.

Accessories

I would suggest a few accessories. A wind screen will enhance the performance in all conditions. Heavy aluminum foil will work fine. A small stove stand to keep the pot just off the burner will keep your pots clean and stable while cooking. Check out the links below for some possibilities. Also a stable base to set the stove on when cooking. Again some heavy aluminum foil will work.

Safety

Always be careful with your stove. NEVER use it inside your tent. Fire or CO could seriously injure or kill you. Lastly, always let your stove cool off completely before packing it or re-fueling it.

Unsealed alcohol stoves are inherently dangerous, since spilling is possible and the fuel burns with a nearly invisible flame. Trangia offers an anti-flashback fuel bottle with auto shut-off pourer.