Most stoves can use either liquid or gas fuel, but not both (one exception is the Primus Omni/Multi-Fuel). Gas fuel stoves are simpler to operate than liquid fueled stoves. The gas, already being pressurized, flows from the fuel canister into the burner, where it ignites in the same manner as a domestic kitchen stove.
Liquid fuel stoves are more complex because the liquid fuel must be vaporized prior to burning. To accomplish this, the stove design brings the fuel line containing the liquid fuel near the flame of the burner. The heat from the flames converts the liquid fuel to a gas before it reaches the burner, where it mixes with air and is ignited. Some models use a spray system that does not require preheating.
Most stoves operating with liquid fuels must be heated or primed before the burner is turned on. Many stoves require the operator to open the fuel valve
briefly without igniting the fuel, so that it flows into a small pan. This small quantity of fuel is then lit and allowed to burn down. When the fuel valve
is opened again, the fuel vaporizes from the heat of the pan. Some stoves do not have this apparatus and must be preheated by the application of an external heat source such as a solid fuel block.
In many stoves, the priming pressure is generated by a small hand pump
that forces air into the fuel container. As the fuel is consumed, the pressure decreases according to Boyle's Law, so the pump
must be operated occasionally during use to maintain steady stove operation.
Gas fuel is sold in canisters, typically under sufficient pressure that almost all of it is actually in liquid form. For backpacking stoves, butane or a mixture of propane and isobutane are used. Camping stoves use either of these or pure propane, which requires a particularly heavy-walled container.
Butane and Propane
- adjustable (permits simmering)
- Not optimal for temperatures below freezing
- Ultralight stoves (often homemade, see ZenStoves.net)
- Cheapest solution
- World wide availability
- All weather use
- Primary required
- Stoves will require cleaning
Magnesium Heaters were made popular by military meals. Magnesium Heaters are available for the public to purchase.
- Flameless (chemical reaction which releases heat).
- Only require water to activate
- The user has no control on heat output
- Difficult to use on food that is not designed for Magnesium Heaters
- Easy to light
- All weather use
- Priming is required
- Low availability outside of United States
Many stoves are designed to use multiple fuel types. These stoves are particularly valuable if you plan to travel
Old film containers are ideal match containers. Always store matches in at least two places in case one set becomes destroyed.
To create waterproof matches, dip the heads of each match in finger nail polish. After they are dry, you have water proof matches (yes, it's that easy). Use the 'light anywhere' matches to make them easy to light when wet.
Many camping and backpacking stoves have piezoelectric self-ignition mechanisms so that they can be lit without a match. They use the mechanical work done by the operator in depressing a button to create an electric spark. Because matches blow out easily, these devices provide an advantage in windy conditions. Matches are also less convenient to use and pose a fire hazard if used improperly. Disadvantages are low reliability, additional (vulnerable) parts, and additional weight.
Gas vs Liquid Fuel
Gaseous fuels have many advantages; the fuel burns cleanly. They are quite simple to use, just adjust the fuel flow with a valve
and light the burner. Since the gaseous fuel quickly dissipates, the fire hazard associated with leaking fuel is reduced. Safety is also increased because there is no priming, however undetected leaks in larger gas bottles can cause explosions. Gas fuel bottles of a particular make may be widely available in some countries but not in others, so international travelers have to be particularly careful.
Some disadvantages of gas fuel are the difficulty of transferring fuel from one container to another and the difficulty of accurately gaging how much fuel remains in a container. Gas fuel is somewhat less efficient than liquid fuel, meaning more fuel volume is required for the same heat output. Gas fueled stoves usually do not operate well in colder temperatures. Butane in particular, does not vaporize well at low temperatures which makes stoves fueled with butane unsuitable for cold weather camping. Boiling point of butane under normal pressure is -1°C and under this temperature butane cannot be used as a fuel for gas stove. The temperature where use of butane becomes impractical is even higher (around 5°C). Propane-butane-isobutane mixtures used in most containers are suitable to temperatures of -10°C. Pure propane boils at -42°C which is the actual limit of usability of propane stoves. Gas fuel canisters tend to be heavier than liquid-fuel bottles, because it must be stored under greater pressure. When a canister runs out, it may have to be treated as hazardous waste. Canisters tend to deteriorate and leak if stored for several years.