The following post describes the development and testing of a simple lightweight and compact stick burning Miniature Dome Stove. It packs within a cooking pot/s and provides for tent heating/cooking, outdoor cooking as a blower stove and backup alcohol cooking. Its simplicity, effectiveness, ease of operation, universality and safety will make it eclipse my previous beloved inverted J-burner stoves and blower stoves.
Background
My previous posts MICRO TENT STOVE DESIGNS, EXPERIMENTAL BARREL STOVE FROM A COFFEE TIN, PUDDING BOWL STOVE and BLOWER STOVES should help to provide a context for what I report here.
Back to the beginning for a moment. I spent a cold night in a rock shelter because camping on deep wet slushy unexpected snow was not an option. It would have flooded our bedding in an ever-deepening pool of water/snow. We made a shelter with the tent canopy under a rock ledge. I realised that the intense heat that could be generated from a tiny amount of damp wood sticks in a suitable tiny container could make the difference between a very uncomfortable experience and a tolerable one. This inspired my journey of searching for the ultimate stick stove. I think this post shows that I have reached that destination.
This video below may help you better understand all my following ‘gobbldygook’ that I use to try to explain this rather complex, but exciting innovation. Please forgive the ‘gobbldygook’ as the excitement of discovery brings this on.
In time, I will attempt to explain/clarify things if you have questions.
“For me, answering questions and the writing process of the posts is my best way of separating what I think I know from what I know I know. “
My PUDDING BOWL TENT STOVE was yet another stove in my long line of experimental tent stoves that have wrought success from failure. It was a tiny derivative of big simple drum stoves that were used in ski chalets in my youth. It had a stable/hot, clean and efficient burning characteristics. Importantly, it had less propensity to REVERSE BURN when compared with my previous downdraft J-burner stoves. However, a lesser reverse burning problem remained even though it required less complex management of fuel loading to prevent reverse burning.
The most obvious limitation of the Pudding Bowl Stove was that the full use of the circular cooktop was obstructed by the flue pipe and fuel stick feed fittings. In short, it was a great tent heater with limited cooking capacity.
Below, I describe the detailed steps that I took to design and test a better tent stove to address the above problems. Also, I describe how the design serendipitously morphed into an ultralight backpackers winter dream of a ‘three-in-one’ stove.
Miniature Dome Stove design concept
Miniature Dome-Tent Stove. I redesigned the PUDDING BOWL TENT STOVE to make the whole cook top available for cooking by putting the two holes for the flue pipe and fuel feed adjacent to one another on the side of the pudding bowl/fire dome. The flue pipe was connected via a 90-degree elbow made of stainless steel foil. I made a long curved scoop or slide that fitted into the fuel port to support the fuel of long bush sticks. The slide was designed this way so that it could be removed and safely wrapped around the rolled-up flue pipe while backpacking.
“Then in my mind, I turned the fire dome upside down. I stretched my imagination (It is rather rubbery.) and I could immediately see that I had created a thing that looked very much like my FIDDLE-FREE BLOWER STOVE. I have used this type of stove for backpacking for many years for fast outside cooking with damp bush sticks.
See if you can tell which of the photos below is the Miniature-Dome Blower Stove or the original Fiddle-Free Blower Stove?
“If you could not guess, I would not blame you. Even I need to look twice! The second photo is the Miniature Dome Stove being used as a blower stove for outdoor use.”
Miniature Dome-Blower Stove. To convert the tent stove to a blower stove, I cut a 20mm dia port in the wall of the pudding bowl to allow the optional fitting of the USB FIRE BLOWER.
These ultralight blower stoves use bush sticks to provide powerful and fast cooking outside for an individual or a group of people. They can quickly make abundant hot drinks, melt snow and cook hot meals just with a hand full of sticks. The heating power that is derived from the blower means that the stove will cleanly burn damp fuel sticks. It can also heat a second pot with the waste heat from the exhaust port when required.
Miniature Dome- Alcohol Stove. Lastly, the blower stove configuration can also be used with an alcohol burner when required. It provides a stable pot stand, a spill tray, a windshield and a means of heat-feed-back (for cold alpine conditions) for the alcohol burner.
Part 1. Testing the Miniature Dome Stove in ‘tent stove mode’.
I did these tests in two stages so that I could assess any detrimental effects of each change somewhat separately.
Stage 1- Side flue pipe. I blanked off the flue pipe hole in the Pudding Bowl Stove (leaving the fuel stick hole open). Then I cut a new hole in the wall of the bowl (or fire dome) to connect the flue pipe using a connector cone and a 90-degree elbow.
The stove worked well (see the video link below) with the flue pipe connected to the side of the fire dome. If you look carefully you can see the fuel sticks drop down a little as the lower ends break down into charcoal chunks. This self-feeding functionality will be lost in the next design change. However, it was never totally reliable when using rough bush sticks as shown in the above photo.
Here is a link to a little Instagram video of the stage 1 stove.
I was excited with the performance and only did limited burn testing as I was keen to move on to the next stage that could make the stove a serious cooking device. No REVERSE BURN was observed. However, I should have expected some reverse burning because, after all, the burner design is in fundamentally an inverted J-burner that has a longer pyrolysis zone and a shorter fuel stick tube than my previous J-burner stoves.
I subsequently did more testing over several hours and REVERSE BURN occurred three times when I left the stove unattended with a big fuel load of dense thick eucalyptus sticks. “These sticks make wonderful hot and long-lasting fuel, but they also form dense charcoal that is strong and resistant to collapse. This, in turn, can cause flame stalling and reverse burning.”
During the above extensive testing, I also monitored the stove temperature and confirmed my initial observation that the dome temperature was typically 100C higher than that achieved with the stage 2 design.
Stage 2- Side mounting of flue pipe and fuel port. The next step was to have both the flue and the fuel port in the side of the fire dome so that the whole top of the dome was available for cooking. “The success of the first change justified building a new stove for the second stage change. So there are no patched-up holes here.”
Here is a little video of igniting a stove with a WAXIE FIRE STARTER in the blower port of a stove where the wood gas flame has been deliberately extinguished. “It has become a smoke generator, but the waxie so easily ignites the smoke flame to make it a self sustaining flame once more.”
Discussion- Miniature Dome Stove, ‘tent stove mode’
Water boiling time. It took about 7min to boil 500ml of water. I think most winter campers would be happy with this performance, particularly when confined to a tiny tent on long winter evenings or when pinned down during a blizzard.
Also, it was possible to provoke higher temperatures by adding extra rapidly combusted fuels through the little supplementary air hole. “I have no doubt that my enthusiastic tent companions will continue to take great pleasure in ‘provoking the fire dragon’ in this way as they have with my other tent stoves in the past. After all, it is a great sport, it keeps you warm and there is not much else to do on a freezing night in a tiny winter tent.”
Stove temperature. The Miniature Dome Stove reached about 350C on the hottest parts and this was about 100C lower than the related Stage 1 stove and the PUDDING BOWL TENT STOVE. I find the temperatures measured with an infrared thermometer are unreliable and considerably underestimates high temperatures on metal surfaces. The ever-changing temperature/coloured heat patterns are best described by my still-photos as my video recording of the same phenomenon was a little disappointing. Nevertheless, the stove was very hot for warming tent occupants and cooking as shown by the series of night time photos below. “An absolute joy to have in the centre of a small tent in a very cold world when the days skiing activities no longer provide body heat.”
Here is a short nighttime video of the tent stove.
I hope it demonstrates what a wonderful heat source the stove can be. The gentle chuffing sound is a constant reminder that all is well within the stove. Fading of the chuffing is a gentle reminder to push the fuel sticks in a little to provide maximum heat. “The stove talks gently to you.”
The colour of the stove in the series of night time photos below also shows that the stove is quite hot and probably a lot hotter than the above-measured 350C (If you consult a temperature/colour chart). The photos were taken in a series over a period of about 2min and there was clearly a lot of variation in the combustion dynamics within the stove. “Consequently, it will be difficult to say what the temperature is, except to say that it is bloody red hot.”
Robust combustion without reverse burning. Although the horizontal fuel feed produced lower temperatures it compensated for this by having a very robust burn characteristic. Importantly, it had no propensity to REVERSE BURN with CHARCOAL CHOKING or fuel feed failure as was the case for my more fiddly inverted J-burner stoves.
“It’s is a powerful and fuel-efficient no-fuss stove that requires little skill and understanding to run it safely.
Fuel consumption. The stove burns about 400g of wood per hour which is similar to my other tent stoves with inverted J-burners.
“This is miserly fuel consumption that provides such comfort and convenience for winter camping.”
Lower efficiency- ‘what the heck’. I speculate that the stoves robustness is mainly derived from the strong and ever-present positive flue pipe draft. It means that more heat energy passes into the flue pipe, particularly when the combustion is at full power. This small loss of heat from the fire dome is of no practical consequence when it provides adequate heating cooking power from miserly fuel stick usage.
Is the heat passing to the flue pipe really a lost? My analysis shows that the flue gas temperature may be 200-350C at the bottom of the flue pipe (often flames at the elbow, so this is more like 700C inside!), compared with ~150C with my J-Burner stoves. However, where the flue gas exits the tent is typically less than 100C. So there may not be much heat loss after all. It could mean that much of the ‘lost heat’ will be recovered as radiant heat from the flue pipe. This will provide useful radiant heat for the tent occupants and hot air for the tent for clothes drying etc.
Difference between vertically vs horizontally fed combustion. The previous Pudding Bowl Stove (with a vertical stick feed) does not accumulate much charcoal at the bottom of the sticks. I think this is because only a short portion of the stick ends burn at any given time and much of the incoming air bypasses the wood combustion and is directed downwards into the charcoal bed. This means that combustion of the wood gas is hotter, more intense and more complete as it must mingle with the hot charcoal before moving off to complete the combustion in the fire dome. This also probably accounts for its higher cooktop temperature.
In contrast, the Miniature Dome stove (horizontal stick feed) behaves more like a conventional box stove (“Sorry to admit it, as it does not sound so exciting.”) with a steadily fed fuel supply. It heats much longer lengths of fuel sticks and the resulting wood gas gets a preferential use of the oxygen in the air stream. This means it accumulates a considerable amount of charcoal over time because the incoming air is not forced to mingle so much with the charcoal. “The air can skip over the top.” This means that the combustion of the wood gas may not be optimized by charcoal pre-heating.
Nevertheless, the multiple parallel fuel sticks provide an extensive wood surface (much greater than in a ‘J-burner stove) that is exposed to high temperatures, on a bed of glowing charcoal. The burning sticks contribute to the heating of their neighbours to make a generous supply of wood gas fuel.
“Unlike my previous stoves, any ‘mug’ could operate it despite the charcoal accumulation.”
Charcoal accumulation, a curse or a virtue? If the accumulation of charcoal is not managed well in a J-burner stove it is a curse. It can start an unfortunate chain of events. It stalls the stick feed-in and this deprives the combustion flame of wood gas This, in turn, deprives the flue pipe of hot gas that then deprives the stove of a strong draft and REVERSE BURNING of charcoal that can then ignite the stalled wood fuel.
“This means that unfortunately, the stove burns in reverse, using the fuel tube (within the tent) as the chimney! This is not good and downright dangerous if not properly managed. To be explicit, if falling off to sleep is the cause of the mismanagement, you may have at last reached perfection, it may be your last mistake as you may never wake up to make another!”
By contrast, the charcoal accumulation in the Miniature Dome Stove is a virtue. It maintains gentle and continuous positive flue draft until the last chunk of it is consumed by fire or extinguished in the warm bed of ash. It ‘holds fire’ for a long time and is available to quickly initiate the pyrolysis of wood gas after refuelling with fuel sticks when refuelling has been neglected.
“This means that the stove just keeps burning safely even if neglected.”
I have a separate post on the vastly different physical and chemical properties involved in the COMBUSTION OF WOOD AND CHARCOAL. This may be helpful background information related to the above discussion.
Fuelling with the horizontal stick slide. The long curved fuel stick scoop or slide worked well and allowed long sticks to be easily used as fuel with minimal preparation. They required manual feeding, rather than gravity as with previous stoves. It was simple and easy to manage. The ‘automatic’ feeding of the vertical burner tube is problematic when irregular bush sticks are used as fuel. Consequently, it is not such a loss.
“Both stoves need manual attention and the operator gets to enjoy the warmth while doing so.”
When the fuel sticks are long (overhanging the slide), dense damp and heavy they require considerable support from the slide. The curvature of the slide (10g) makes it very strong and it can support the load. However, the cone connector between the slide and the fire dome must be locked in place to prevent the slide from ‘drooping’. Alternatively, the slide can be supported by the ground if the stove is operated at ground level.
On the other hand, if the stove is operated well above the ground, as in a snow camping situation, the cone needs a locking device to provide this support for the slide. “As usual, I have come up with a couple of tricky mechanisms that can provide this support without adding significant weight or bulk for the backpacking load. This will be the subject of another post.”
Lastly, once the ‘stick slide droop’ problem is fixed, a new issue can arise for those who ambitiously load up the fuel slide. The ultralight fire dome and rollup flue pipe may tip over as they are not heavy enough to counterbalance the fuel load. Ground mounting avoids the problem. Mounting on wooden legs and use of a fine wire tie as mentioned later make other solutions.
Refuelling alert. Conveniently, the fading of the gentle pulsating sound, from the wood gas flame, creates a timely cue to push the sticks in if you are distracted by cooking duties or too busy discussing skiing exploits. Luckily, the robustness of the long burn zone, in this horizontal configuration, makes it ‘hold fire’ well and be very tolerant of operator neglect and lack of fire skill. The 20mm dia hole also makes a simple and easy ignition point if rapid flame restarting with a WAXIE is required.
Always upward stove draft. The long horizontal burn zone may be less efficient than in my ‘J-burner designs, However, this is more than offset by the simplicity of operation and the absence of the problematic REVERSE BURNING issues with the ‘J-burner stoves. There is no reverse burning because the gas/flame path is ‘always-upward’. “There is no longer a critical dependency on wood gas to sustain positive flue draft.”
Lower stove temperature. The horizontal burner configuration of the Miniature Dome Stove results in lower cooktop temperatures than the equivalent Pudding Bowl Stove. The photos of the two stoves (at peak temperature) below demonstrate the difference.
I speculate that it may be caused by the poorer mode of air entry and poorer turbulence for mixing of the air with wood gas within the fuel sticks in the horizontal fuel feed configuration. However, this is a small loss given the large unobstructed cooking surface of the Miniature Dome Stove design.
Burner flame guide. Both Pudding Bowl and Miniature Dome Stove use a simple flame guide device to force most of the flame/hot gas to move across the burn chamber and then back to the exhaust port. This extends the wood gas combustion path so that most of the combustion is completed within the fire dome and improves the heat exchange to the stove cooktop.
The flame guide is made of very thin bent stainless steel foil and is only loosely clipped in place. It is surrounded by very hot flame and gas with no opportunity to sink heat into any other part of the stove. It will be destroyed in time and so it should be a simple, cheap and easily replaceable component.
Safer location of the fuel entry port pipe. The Pudding Bowl Stove and my J-burner tent stoves have the fueling area that is close to and aligned with the very hot lower portion of the flue pipe (sometimes 300C). This design compromise was introduced to maximize the area of the cooktop that can be used for cooking. This means that there is a high risk of burning knuckles on the flue pipe while managing fuel loading. “I know this from experience” The Miniature Dome Stove design removes this problem by having the flue pipe and the fuel entry orientated at right angles to each other.
Aluminium foil stove bottom. I had initial reticence about using thick aluminium for the bottom of such a hot stove. However, extensive testing shows that it works quite well. “Additionally, such foil is plentiful as waste from ‘shop prepared’ and takeaway foods that dominate many diets today. So it will be cheap and easy to replace if needed even if you don’t eat much of this food .”
The foil bottom worked very well and was undamaged after many hours of burn time. Importantly, its easy removability makes the stove easy to transition to a blower or alcohol stove.
The bottom of the stoves can be protected from excessive heat by a thick layer of ash (~7mm). I like to add the ash to the stove before lighting, but it accumulates in the stove in any case. The ash can also block air entry through cracks in joints around the base.
The foil can also be further protected by a simple disk of thin metal such as titanium, stainless steel foil, aluminium flashing metal or thin tinplate (such as the cut out of a lid of a large ‘tin-can’) that is placed above the foil cover. This will also provide mechanical protection for the foil stove bottom.
A more secure stove bottom. The Miniature Dome Stove can be mounted upon bush stick legs in a snow pit (My favourite method for snow camping that is detailed below). In this situation, a more substantial supplementary base can be clipped on to the bottom to make it even more secure, but the original aluminium foil will still be needed to restrict inward air leakage and spillage of ash. “This would ensure that the contents of the burner could never crash out into the tent.”
Stove bottom temperature. The ash insulation still allows parts of the stove bottom temperature to reaches wood charring temperature. This means that special insulation precautions need to be taken to safely and effectively mount the stove in a small tent when camping on snow or on the ground.
I prefer to have no floor in my tents where the stove is mounted. This means that there is no risk of burning the floor and it also allows the construction of a snow-pit that can greatly increase the comfort and amenity of snow camping.
The required insulation can best be provided by keeping the stove bottom a suitable distance from the snow or heat-sensitive surfaces. “Air is a very light and effective insulator and is an effortless backpacked item.”
On-ground stove mounting. There are many ways in ‘non-snow camping situation’ to provide the required stove mounting. The stove could be sat directly on the ground if it has very little organic matter content that can burn or charr. “The miracle of combustion means that an enormous amount of smoke can be made from a tiny amount of organic matter.”
The stove can be placed on a stack of rocks. My preference is to have a large flat rock that can be supported and levelled by placing three rocks below it. This arrangement is delightful as the rock will absorb heat and become a hot table/shelf that can keep drinks and meal warm, dry gloves, socks and fuel sticks etc (above and below). It will also be a heat bank when the fire runs down.
On-snow stove mounting. A ‘crisscross raft’ of bush sticks placed on the snow could work if layers of aluminium foil were used as both heat reflectors and heat dissipators. The use of the wire ties, described below, would be advisable. Additionally, the top layer of sticks could be simply wrapped in foil to prevent their charring.
Securing the stove dome. The stove is so light (109g) that it can easily be pushed sideways while pushing in fuel sticks (or toppled over by a large load of heavy fuel sticks as mentioned above). The temporary use of a handheld fuel stick or a small rock to provide a resisting force is a simple solution to this problem. However, a more convenient solution is to place rocks or even a pot of water in such a position as to provide the resistive force.
An even better solution is to use some thin wire to ‘tie’ the stove down to a rock or the wood stick raft. In this, case three mounting clevises can be used as the attachment points.
[Add photo of stove wired down to wood stick raft]
Mounting the stove on bush poles. When camping on deep snow I like to mount my tent stoves high up on wooden bush poles that are driven into the snow surface down in a snow pit (TENT STOVES). I find this is the ultimate mounting method in a small tent. It optimizes the distribution of radiant heat to the tent occupants bodies and makes cooking and refuelling easy. It also provides a suitable space and structure to form a simple ‘fuel stick’ storage and drying rack below the stove.
Part 2. Testing the Miniature Dome Stove in ‘blower stove mode’.
By contrast with Part 1, for me, it was a bit ‘routine’ as I have grown to know what will and probably will not work as a BLOWER STOVE. I have a wheelbarrow full of ones that did not quite work. Nevertheless, the test still should be reported.
Discussion- Miniature Dome Stove, ‘blower Stove mode’
Performance. As expected the Blower Stove configuration of the Miniature Dome Stove worked very well. It boiled 500ml of water very quickly (about 5min), which is not quite Jetboil rates, but it is unlimited and fast enough to satisfy a group of thirsty and hungry skiers or trekkers.
Excess heat. The exhaust flames are excessive as the fuel sticks were dryish under test conditions (hot summer). However, the flame will moderate under alpine backpacking conditions in winter when the fuel sticks are invariably moist.
Cooking in a second pot. Regardless of moisture content, there would still be the opportunity to effectively heat a second pot over the exhaust flame, as with many of my blower stoves. This position is excellent for simmering dinner while the primary pot is used for rapid water boiling and snow melting etc. Two of the above-mentioned clevis fittings can be used to connect a titanium wire to provide one of three support for a second cooking pot.
Two separate fuel/exhaust ports. This is the first time I have tested a blower stove with two separate fuel/exhaust ports. Loading sticks through two ports was simple. The aggregated area of the two ports was only ~60% of that of my traditional rectangular ports, but there was ample room for enough fuel sticks and adequate clearance for exhaust flam/gas.
The 60% reduction in the exhaust area did not reduce the quality of the combustion. The restricted area worked so well that it may become the standard for my FIDDLE-FREE BLOWER STOVE. It will need further testing, but I had the impression that the smaller port area made the flames vent in a more controlled way with less tendency for FLAME ROLL-BACK UNDER WINDY CONDITIONS.
Part 3- Testing the Miniature Dome Stove in ‘alcohol burner mode’.
Trangia spirit burner. I first tested a Trangia spirit burner (130g) in the stove and the flame was spilling around the edge of the pot and it would have been very inefficient. Furthermore, the burner got too hot and it started to have an uncontrolled flame above where the normal flame should be.
Whisky bottle top burners. Next, I tried my WHISKY TOP BURNER in the stove. One was an aluminium whisky (or wine) bottle lid (3g) and the other was the same lid with an additional ultralight foil flame guide (extra 2g) that directed the flame up under the pot.
Here is a little Instagram video of the alcohol burners.
The above burners were very efficient and could boil 250ml of water with about 7g of alcohol. The time to boil was longer for the simple burner and the alcohol use was a little more for the faster boiling burner with the flame guide.
General discussion.
Stove weight. The Miniature Dome Stove including a 6’*40mm dia roll-up flue pipe weighs just 402g. The 1L stainless steel cooking pot and aluminium foil lid add another 134g. The USB blower unit with air port, power supply and battery adds a further 130g. The total weight of the Miniature Dome Stove with its pot is ~650g.
Packing. The Miniature Dome Stove packs very efficiently inside the 1L custom cooking pot. This makes a backpack-friendly load and there is room within for other cooking gear, pot grip and fire starters etc. This pot could be nested inside a second larger pot (1.5L and 75g ) if needed to provide luxury cooking.
“I like to have a large dinner pot and a separate pot for boiling water, for plenty of hot drinks for rehydration and snow melting for water while dinner is prepared.”
The freedom to pack easily within and around the fire dome is in sharp contrast to my previous rectangular or oval J-burner stoves where access to the fire dome interior was; limited, fiddly or nonexistent. The removability of the sacrificial flame guide and the stove bottom is key to this improved backpacking functionality.
The circular shape of the fire dome and the simple primary cooking pot makes them strong smooth shapes for backpacking. They give mutual strength to one another and provide support to any extra concentrically packed larger pots.
My favourite supplementary large stainless steel dinner pots are super-light (eg. ~1.0L, ~65g, and ~1.5L, ~75g). They need mechanical support of the fire dome and primary pot to survive backpacking in suitable shape. “They will get dented, but not destroyed with this packing method. They are as thin as paper. However, it means that the dents can be pushed out with the use of a rounded end of a stick.”
[Add a photo of three pot kit]
Flexibility. Having tent heating/cooking and outdoor cooking with the one stove makes the stove very flexible for winter backpacking camping. Furthermore, the stove can also be used within a tent with an ultralight alcohol burner for example for a quick breakfast coffee.
A serious source of clean heat? You could be justified if you thought that such a small stove was just a toy. ELSWERE, I have estimated the heat power of a similar stove to be 890w. This calculation assumed that 70% of the heat of combustion of 400g of wood/hour is delivered to the tent and occupants. “This is similar to having a 1000w radiator in a very small tent out in the wilderness.”
“Even if the heat transfer efficiency was only 50% it still would be a serious source of heat. Heat derived from the combustion of renewable wood is a wonderful gift made largely from greenhouse gas and sunlight.”
Improved horizontal fuel stick presentation. This Miniature Dome Stove has lost all the technical magic of the downdraft J-burner stoves. It can be thought of as a miniature ‘conventional’ wood stove with a restricted fuel supply that is progressively replenished by feeding in fuel sticks. “Does not sound very magical when put like that.”
Many conventional stoves have fire grates to improve combustion. These allow the air to enter upwards through the grate, then through the hot charcoal and then under the wood fuel. ‘This adds a little magic.” I briefly tested the lifting of the fuel sticks, at the entry port, with a small piece of bent wire. This closed the ‘slip gap’ above the sticks and also opened up an alternative air path below the sticks. It promoted airflow over the charcoal bed and then under/through the sticks. It appeared to improve the already hot combustion.
Larger fuel port and fuel stick lifter. I intend to explore the possibility of having a larger fuel port. Such a port will simply allow more fuel sticks to be loaded together to give a stronger burn. It will also provide more space to allow me to add a simple fuel stick lifter in the port.
This may be a way of improving combustion and make it perform more like my inverted ‘J-burner’ stoves, but without the problem of charcoal stalling and reverse burning. “It may get some of the magic back.” This is the subject of another post LARGER FUEL PORT AND FUEL STICK LIFTER.
Conclusion
For me, it is somewhat sad to see my beloved J-burner stoves eclipsed by a much simpler, safer and robust but possibly slightly less efficient stove
“That is the nature of progress, and it feels better when done by me rather than someone else. If the J- burner stoves had pride, I am sure that they would claim that they were the genesis of the ultimate backpacking wood stove. “
It is also satisfying to meld my many years of tinkering with Tent Stoves, Blower Stoves and Alcohol Burners into a single Minature Dome Stove. It provides a unique lightweight, versatile heating and cooking system. It is ideal for cold climate backpackers who wish to use found bush sticks as their primary fuel. The three-in-one functionality of the stove means that it removes the hassle of deciding which stove to take on trips where cold weather can be so unpredictable.
An ode to the old and new:
Wow, the rectangular or oval stove seemed great,
I have done some rethinking of late,
A tiny round stove to some, may seem incredibly dumb,
But for heat, pots-packability, safety and agility the circle is ultimate.
“If you are a ‘fellow stovie’ and have not gone to sleep reading this and you don’t get excited about this, I suggest that you check to see if you still have a pulse!”
Here is a brief Instagram video of the working stove. I think it captures the versatility of the three-in-one stove.
If the weight (~650g) is shared by two or more people it is indeed a very small weight per person. There will be no need to carry much fuel or skimp on warmth, good safe water, hot food and plentiful hot drinks for rehydration.
As with all good journeys, there is yet more improvement path to be explored and this will be the subject of other posts.
Please contact me if you would like a bespoke Miniature Dome Stove made for your requirements. CONTACT FORM
A retraction addendum
In this post, I kissed goodbye to my beloved stove design that uses downdraft burners for reasons of inconvenient charcoal choking and hazardous reverse burning. Now the burners have made a Lazarus-like revival in my latest KISS tent stove. This stove surpasses all my previous designs with regard to pack-weight, compactness, performance and versatility. “Now, that’s taking victory from the jaws of defeat. I hope I have got that right.”
Tim
Related posts
Larger fuel port and fuel stick lifter
Reverse burning in Miniature J-burners
FAQs (Three-in-one stove & other dome stoves)
In this cornerstone post. I have added this FAQ section to collate your questions and my answers to make it a little simpler to follow particular threads. This post combines tent, blower and alcohol stoves in the one stove, so I will try to put all relevant Q&As here. Asking your questions in the comments section below would be helpful. We will see if it works? I will also collate questions that are made in comments in other related stove posts.
Also, I have what I call a ‘pictorial gallery index‘ of my many blower stove posts that may help (web dummies like me) find answers to questions or even to frame your questions. The pictures give a flavour of the content of the post along with the words within the links.
Under the name of the questioner, I will repeat or paraphrase the question and under my name (Tinker) I will give my answer. I hope it makes for clear reading!
Nick: What are the dimensions of the stove when packed up?
Tinker: The stove packs up inside its custom 1L cooking pot that is 75mm high*150mm dia.
Nick: First, how hard is it to leave-no-trace with a blower stove? I would expect the main chamber and exhaust flames to share a lot of heat with the ground if not managed.
Tinker: In blower stove mode, I usually put the stove on the ground that has already been damaged or on a rock, sand or gravel that can not be damaged. The same applies to the flame exhaust area. An aluminium tart dish (~5g) could also be used to provide protection to the ground where the blower stove flames shoot outwards from the fuelling ports. Luckily most of the heat goes upwards and is quite capable of heating a second pot. A thick layer of ash or soil in the bottom of the fire bowl also makes an excellent insulator and makes the stove cook faster.
Nick: Second, What is your startup process for a blower stove?
Tinker: This is easy and a delight to do, with a little experience. Please see the youtube link below. It is a roll-up titanium stove without a bottom, but the principles are just the same. The stove with a bottom is easier to light and use and is better for leave-no-trace. The stove can even be picked up with pot tongs and shifted to a better place if required. I often do this while cooking on the stove beside a campfire or in a fireplace of a mountain hut.
youtube Blower stove startup
Nick: Lastly, what is the battery consumption like? mAh / minute of operation?
Tinker: Battery consumption is about 0.12 mA. without the LED lighting. I can get two to three hours of full power cooking from a good 18650 battery. On multiple weeks I have got, from one battery, a week of cooking including water sterilization when I have used my fan pulsing switch on the USB fire blower( I carried 6 batteries on three-week-long Hume and Hovel explores trail walk, just in case). For more details please see:
https://timtinker.com/extending-battery-life-for-blower-stove/
Nick: If it were only going to be used as a tent stove, would it still be advantageous to have the secondary port that is used for the blower in blower stove mode?
Tinker: Yes, the little port is advantageous in tent stove mode. It is a great place to ignite the wood gas (smoke) when restarting the hot stove after an idle period (or neglect). It is also good for adding little extra sticks and chips to supplement big fuel sticks that can be fed in through the main fuel port. Lastly, I provide a little cover plate for the hole when not in use.
Nick: What length of flue pipe would you recommend for a 2m tall pyramid tent?
Tinker: The required length of the flue pipe depends upon how high the stove sits above the ground or snow surface. I like to clear the top of the pyramid by about 200mm. So if you wanted a stove that can sit on the ground, the minimum flue pipe would need to be about 2.1m long allowing for the height of the stove. It will just stick out further if the stove is set up on bush pole legs or a rock bench or a “stone-age table’. The very bottom of the flue pipe will eventually get damaged by the heat, so I would advise you to add a little extra length so that the damaged foil can be trimmed off several times to give the pipe a new lease-of-life. Of course, short extensions can serve the same purpose and keep a pipe serviceable for a long time. So the short answer is 2.2m.
Nick: What is the diameter of the flue pipe?
Tinker: 40mm
Nick: What are the approximate weight and dimensions of the clever aluminum flue gland and pocket you came up with?
Tinker: The details of the gland are in my post https://timtinker.com/tent-flue-gland/ . Weight 7g, dimensions 115*90mm. Importantly, it is removable to make tent stuffing easy. I pack it in a little flat bag with the lay flat kettle and a light plastic ‘window’ that I put in place when not using the tent stove.
Nick: What is the procedure to light the stove and get the flue pipe drafting?
Tinker: The fastest way is to set some light fuel stick, bark, paper, waxies in the fuel port. Then remove the flue pipe and put a thick flaming waxie (or similar) down into the flue pipe connector cone and quickly replace the pipe (The cleaver wide cone connector makes this easy.) and set fire to the starter fuel with a flaming waxie and add progressively thicker sticks until the bed of coals form. Use extra waxies if the wood is damp. Very quick and easy. Without priming the flue pipe this way the stove will start OK, but it will take some gentle blowing into the fuel port just to hasten the warming of the flue pipe. Some chunks of ‘old’ charcoal help greatly in the start-up. They quickly start the important charcoal bed.
Nick: I realize there would be a lot of variability because of the quality and type of fuel used, but approximately how often do find yourself nudging the fuel sticks in, and after it has been stoked up, how long could you neglect the stove? I’m not worried about this data, but am curious.
Tinker: Nudging in of the fuel sticks is required about every 5min, but this is to maintain full power for cooking. Overall, it is very tolerant of neglect and after 30 min it will usually fire up easily using the waxies through the little hole mentioned above. “Of course, putting the right type of solid sticks in preparation for neglect is a good strategy!”
Nick: What is the diameter of the cook top? I have a 1.9L titanium (16.5cm diameter) pot I inherited from a friend who quit hiking and I’m wondering if it might be too wide.
Tinker: The cooktop on the fire dome is about 140mm dia. It fits in its own custom pot about that is about 150mm OD for backpacking and this pot is just perfect for use on the blower stove and with the alcohol burner. It has a rebated bottom edge that makes a lovely fit inside the opening of the fire bowl in blower stove mode. Consequently, both would fit inside you titanium pot if you were to take two pots. If a pot overhangs the cooktop a little it does not matter. However, I avoid using such large pots if I don’t need the capacity as they are less efficient to boil in than a squat pot of the desired capacity (as shown in my post). As an aside, the Ti pot would probably be wide enough to fit on the blower stove fire bowl, but it would sit on the uppermost part of the bowl rim. Large size good for this and boil time is no issue for the powerful blower stove!
Nick: Back home in Canada conifers are often considered a less preferable fuel for fireplaces and wood stoves because of the potential for building up creosote. Would that hold true for your stove or would such fuel be alright? Cedar and cypress are very readily available here in Japan.
Tinker: Regarding pines and creosote. My current stoves burn very hot and clean because they are not overloaded with wood like many other stoves, so I would not expect creosote problems with any wood type. My older stove pipe stunk of creosote so much that I carried the flue pipe on the outside of my pack. I think I could run the stove on creosote if I needed to! I might give it a try when I clean my kitchen stove chimney. I have just experimented with running it on waste oil and it worked. I did a test with some dead Twiggs from my pine tree and it burnt very hot and cleanly. It was rather rotten, so I will try again with some more solid sticks, but I don’t expect a problem. There is an Instagram photo and video of the combustions that shows what a delightful burn that the pine sticks supported.
https://www.instagram.com/p/B_Z9-DZBLCX/
Hi Tim,
Thank you for answering my previous questions.
The three in one miniature dome is getting more and more interesting.
I was wondering a couple mor things:
1) What is the diameter of the cook top? I have a 1.9L titanium (16.5cm diameter) pot I inherited from a friend who quit hiking and I’m wondering if it might be too wide.
2) Back home in Canada conifers are often considered a less preferable fuel for fireplaces and wood stoves because the potential for building up creosote. Would that hold true for your stove or would such fuel be alright? Cedar and cypress are very readily available here in Japan.
Cheers!
Hi Nick, Thanks for more questions.
1. The cooktop on the fire dome is about 140mm dia. It fits in its own custom pot about that is about 150mm OD for backpacking and this pot is just perfect for use on the blower stove and with the alcohol burner. It has a rebated bottom edge that makes a lovely fit inside the opening of the fire bowl in blower stove mode. Consequently, both would fit inside you titanium pot if you were to take two pots. If a pot overhangs the cooktop a little it does not matter. However, I avoid using such large pots if I don’t need the capacity as they are less efficient to boil in than a squat pot of the desired capacity (as shown in my post). As an aside, the Ti pot would probably be wide enough to fit on the blower stove fire bowl, but it would sit on the uppermost part of the bowl rim. Large size good for this and boil time is no issue for the powerful blower stove!
2. Regarding pines and creosote. My current stoves burn very hot and clean because they are not overloaded with wood like many other stoves, so I would not expect creosote problems with any wood type. My older stove pipe stunk of creosote so much that I carried the flue pipe on the outside of my pack. I think I could run the stove on creosote if I needed to! I might give it a try when I clean my kitchen stove chimney. I have just experimented with running it on waste oil and it worked. I did a test with some dead Twiggs from my pine tree and it burnt very hot and cleanly. It was rater rotten, so I will try again with some more solid sticks, but I don’t expect a problem. There is an Instagram photo and video of the combustions that shows what a delightful burn that the pine sticks supported.
https://www.instagram.com/p/B_Z9-DZBLCX/
Regards & stay safe,
Tim
Hi Nick, I have just posted on my latest Simple Dome Stove https://timtinker.com/simple-dome-stove/
It is very sweet, simple, powerful and effective, but with only a small but serviceable cooking space. Let me know if it appeals to you.
Hope things are OK with the virus, very few new cases here and things are starting to relax a bit.
Stay safe, Tim
I have a few questions specifically about the miniature dome stove when used as a tent stove.
1. If it were only going to be used as a tent stove, would it still be advantageous to have the secondary port that is used for the blower in blower stove mode?
2. What length of flue pipe would you recommend for a 2m tall pyramid tent?
3. What is the diameter of the flue pipe, and what are the approximate weight and dimensions of the clever aluminum flue gland and pocket you came up with?
4. What is the procedure to light the stove and get the flue pipe drafting?
5. I realize there would be a lot of variability because of the quality and type of fuel used, but approximately how often do find yourself nudging the fuel sticks in, and after it has been stoked up, how long could you neglect the stove? I’m not worried about this data, but am curious.
Cheers!
Hi Nick, thanks for your great questions.
1. Yes, the little port ist advantageous in tent stove mode. It is a great place to ignite the wood gas (smoke) when restarting the hot stove after an idle period. It is also good for adding little extra sticks and chips to supplement big fuel sticks that can be fed in through the main fuel port. Lastly, I provide a little cover plate for the hole when not in use.
2. The required length of the flue pipe depends upon how high the stove sits above the ground or snow surface. I like to clear the top of the pyramid by about 200mm. So if you wanted a stove that can sit on the ground, the minimum flue pipe would need to be about 2.1m long allowing for the height of the stove. It will just stick out further if the stove is set up on bush pole legs or a rock bench or a “stone-age table’. The very bottom of the flue pipe will eventually get damaged by the heat, so I would advise you to add a little extra length so that the damaged foil can be trimmed off several times to give the pipe a new lease-of-life. Of course, short extensions can serve the same purpose and keep a pipe serviceable for a long time. So the short answer is 2.2m.
3.1 The flue pipe diameter is ~40mm.
3.2 The details of the gland are in my post https://timtinker.com/tent-flue-gland/ I have not got the specification, but by looking at the photos you could estimate the size, given that the hole through the aluminium foil is about 40mm die. I simply make a bigger gland for my 50mm flue pipe, so the pocket that they fit in is slightly bigger than is needed for 40mm. The weight of gland is very small, but I will need to weigh it.
4. The fastest way is to set some light fuel stick, bark, paper, waxies in the fuel port. Then remove the flue pipe and put a thick flaming waxie (or similar) down into the flue pipe connector cone and quickly replace the pipe (The cleaver wide cone connector makes this easy.) and set fire to the starter fuel with a flaming waxie and add progressively thicker sticks until the bed of coals form. Use extra waxies if the wood is damp. Very quick and easy. Without priming the flue pipe this way the stove will start OK, but it will take some gentle blowing into the fuel port just to hasten the warming of the flue pipe.
5. Nudging in of the fuel sticks is required about every 5min, but this is to maintain full power for cooking. Overall, it is very tolerant of neglect and after 30 min it will usually fire up easily using the waxies through the little hole mentioned above. “Of course, putting the right type of solid sticks in preparation for neglect is a good strategy!”
I hope this helps,
Tim
Hey Tim!
I just wanted to thank you for your contributions to the outdoor community. I read as much as I could of your articles on bpl (not a paid member), and am really happy to have found what you are putting up here about tent stoves. I’m a fellow skier and winter camping enthusiast (XCD skiing in pocket backcountry Japan if that makes sense), and I will definitely put together a hot tent when I have enough disposable income in my pocket (3 young kids, 1 income). Roughly how much would you charge for a dome stove?
Feel free to PM me about it, or If you’ll be in Japan.
Hi Nick, I am glad that you enjoyed my posts. I started posting with BPL but was mysteriously locked out from making comments, even on my own articles. I don’t think I have done anything to justify this. I think the BPL fee for viewing article is a putoff anyway and comments seem to be from a limited pool of people. Anyway, I have moved on from this ‘lockout’ and it spurred me on to make my first website for sharing my ideas with people like you. It has been great creative fun and I have enjoyed learning about posting etc (Still a lot to learn.).
We share a lot of interest, but I don’t understand the ‘pocket backcountry japan’ skiing term. Maybe I have another ski discipline to learn? Where about are you in Japan? It is a wonderful country and such nice people. Think of this combination in context of WW2. I was of a group of Aussie skiers involved in a rescue of a Japanese lady skier who was out of sight waist-deep in the water down a deep ice hole over a stream. Our, rescue rope that we were carrying was used by some strapping young German lads who pulled her out of the hole. After the rescue, we found that she lives in Australia. It put new meaning to our funny little saying of “shhhh don’t mention the war!”
Regarding tent stoves, the Miniature Dome Stove is my ultimate tent stove and in all regards other than ‘bento box cuteness’ makes the designs in BPL rather redundant. It is a new design that has just been tested after returning from my ski trip in Japan (More like being chased home by Coronavirus.) I have not set a price for the stove but I don’t want anyone to not have on on account of the price. So I am sure that I can come up with an attractive deal especially with your family commitments. Also, I would like you and others to be able to use the stove and provide feedback and reviews of its performance out of the hands of its creator. How big is your tent? I presume that you are not in a hurry? I will send a PM you to discuss further, but please post any technical questions etc here so that interested outdoor community people can see the discussion.
Tim
I may be misusing the term or creating my own because of a faulty memory, but I use pocket backcountry to refer to smaller areas of less rugged but still natural and ungroomed terrain. I live in Osaka, and usually play around in the mountains in Shiga. I’m not a strong skier so I keep it very moderate.
Regarding the dome stove, I was curious about the packed dimensions of the stove, particularly the bowl unit itself.
Lastly, you’re correct- not in a hurry. Sadly, winter here is over and won’t be back until December in my local hills.
Hi Nick, Your term pocket backcountry is a perfect description even if you made it up. It sounds like the skiing that I do on the Baw Baw plateau. No infrastructure there, not very high or steep, but still heaps of fun. Here is an Instagram video sample https://www.instagram.com/p/B12tPq-Fnzs/
Not nearly as nice as the snow in your pocket country I bet, but on our pattern base skis, we can easily travel big distances and climb ski slopes quickly for lots of downhill runs.
To stoves, I will have to get back to you about the packed stove dimensions when I get home. There is the bowl that the fire dome is made from and another bowl that is the cooking pot and the fire dome neatly fits within the cooking pot for backpacking.
Tim