Lightest backpacking stove.

This article describes a 125g lightest backpacking stove that can burn damp wood sticks and simultaneously cook in two pots.

Background

For years I was searching for a better wood fuel stove for alpine walking and skiing backpacking where abundant heat was always welcome when the action was over. Wet cold fuel sticks were usually encountered and they were difficult to burn in natural draft stoves twig stove article. I also wished to eliminate the tedium of preparation of little fuel sticks to keep the stove burning. I was at the same time encouraged by the intense controlled heat that could be produced by a hand full of bush sticks in my ultralight tent stoves. In this case, the draft produced by the flue pipe causes strong incoming airflow that causes a clean and controlled burn. The airflow meant that even damp fuel sticks will burn well Ultralight alpine tent stove. This combustion is a complex sequence and I have described the process in combustion of wood and charcoal. I applied these combustion principles to stick stoves for outdoor cooking with wet alpine sticks.

The inspiration

A tiny fan from a discarded laptop inspired me to turn assorted tin cans and kitchenware into backpacking stoves. My challenge was to control the burn and harness the heat for cooking a primary fast boiling pot and at the same provide gentle heat for dinner simmering. I also wanted a backpacking stove that would be; light, compact, durable and pack friendly. Ideally, I required it to be able to burn long damp fuel sticks with minimal preparation.

The following photos show the potential power of some of my not quite right experimental backpacking stoves. I also have included them to assure you that I did not instantly dream up my ideal design. It was a journey.

A view looking down on a boiling pot on a powerful ring backpacking stove. Heat is wasted as flames escaping between the three pot stand legs. For years this effective but inefficient type of backpacking stove was my favourite. The cook also had to frequently dodge the flames while removing the pot to add little broken up fuel sticks to the small burn chamber. Stirring the pot in situ was just not possible. Nevertheless, this little stove produced a lot of free boiling water for many happy campers and volunteers would happily keep up the supply of suitable little broken up fuel sticks in exchange for unlimited boiling water.

An example of a ring backpacking stove that results in the flame pattern shown above. The 30g (1oz) stove burn chamber has a fine ‘tongue and groove’ joint in the wall that allows it to be rolled up for backpacking inside a mug.

A C-ring backpacking stove easily boiling a pot of water with a wasteful flame that is at least directionally controlled away from the cook, but its potential to heat a second pot is wasted.

An example of a backpacking stove that provides mastery of combustion with long damp fuel sticks and can provide rapid boiling in one pot while simmering another pot is shown in the photos below. Blower Stoves.

A large roll-up titanium two pot backpacking stove including a wing wall support for a second pot. It all rolls up to fit inside two nesting large pots and only weighs about 600g including the second larger pot. This stove is provided with a little LED cooking light. There is ample heat for simultaneous boiling of water for hot drinks, soups etc while simmering dinner, drying fuel sticks in preparation for their easy combustion and providing heat to keep the cook warm. Suitable for 3-4 people.

Blower Stove Minimization

The above backpacking stoves are made of fine stainless steel and titanium and they became more and more sophisticated to improve their functionality. Consequently, I considered it was time to take the combustion principles discovered from these stoves and apply them to primitive stoves (low weight and cost) that required no formal stove body other than rocks collected from a campsite. Alternatively, where rocks are unavailable or they are the ones that explode when heated, the burn chamber and pot support can just be a hole in the ground. This was the genesis of the Rock-N-Hole backpacking stove. It is for those who want convenient cooking without needing to carry the stove or fuel.

Rock-N-Hole backpacking stoves

All my backpacking stoves use the same blower unit with various ~5V dc power supplies. My favourite Lithium-ion 18650 battery of about 45g housed in a USB charge management tube (blue colour in the photos) can provide cooking for 2-3 h or much longer if it has an on/off pulsing switch to conveniently regulate the combustion rate and simply allow simmering on hot coals without a fan-forced air supply. The Rock-N-Hole backpacking stoves require an air tube extension to protect the fan from radiant heat from the burner. In another configuration, a tiny air elbow attachment is required to bend the air flow downwards into a hole in the ground air extension tube and dragon head.

A blower stove that is formed by earth or rocks acts as a good heat insulator so there is more heat for cooking. If the burn cavity is long it can support multiple pots. This is convenient as the stove naturally has a fast boiling position closest to the blower outlet and a simmering position beyond. Another delight of the rock stove is the residual heat stored in the rock can make a nice ‘sleeping bag warmer’ when wrapped in a suitable cloth.

Lightest backpacking stove. A two-pot Rock-N-Hole backpacking stove where fuel sticks are fed in opposing the blower air flow. The hot gases from the primary burn zone will dry the incoming fuel sticks in preparation for combustion. In this configuration, the normal air tube is extended by one unit to put the fan and battery out of reach of strong radiant heat from the glowing charcoal bed. The air tubes are modular so they can be removed from the blower & battery unit and be packed up in a something as small as a large coffee mug.

Lightest backpacking stove. A two-pot Rock-N-Hole backpacking stove boiling water vigorously in the pot nearest the blower and simmering in the other pot.

Lightest backpacking stove. A trench style two pot Rock-N-Hole backpacking stove where fuel sticks are fed in opposing the blower air flow. The insulation of the soil burn chamber directs intense heat into the cooking pots and rapidly dries the incoming fuel sticks in preparation for combustion.

Discussion

I can hear some people saying; “Why not just use a fire for cooking?” Well, a blower stove has the following advantages:

• It can be much smaller than a campfire, particularly when fuel is wet.
• Uses much less wood where wood is scarce.
• Very quick to reach cooking temperatures.
• Fast recovery of cooking power after an idle period.
• Heating is concentrated on the bottom of pots and not up their walls.
• Easily burns damp and wet wood.
• Pots are less likely to spill.
• Cooks’ hands are free of flames and radiant heat and in situ stirring is easy.
• Fuel can be added without interrupting cooking.
• Lastly, a blower stove can be used for convenient cooking in conjunction with a campfire for warmth.
• Lastly, the blower unit is just great for starting campfires under difficult conditions.

“I remember my friend Jack saw the stove for the first time one evening. The next morning was cold and damp. Before I was out of my sleeping bag he had my blower and was breathing fire into a bed of remnant charcoal from the evenings’ campfire to encourage us to get up and going.”

Fire starting with USB fire blower

For the whole blower stove story please see  Full Article.

Tim

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