Tent stove from a biscuit tin
This is another free tent stove that can be made from a biscuit tin or cookie tin and a scrap of corrugated roofing iron.
Introduction
Previously I have described tiny compact tent stoves that are made of stainless steel and designed specifically for ultralight backpacking in winter.
More recently, for base camp situations, I have made a larger tent stove out of a 20L cooking oil drum. The light mild steel sheet metal makes construction easy. However, it will cause the stove to have a delightfully hot surface for cooking and heating, but relatively short life.
The current stove is of intermediate size. It is made from a tin plate biscuit tin (175mm dia) and a scrap of old roofing iron. The stove should be suitable for base camping or could also be backpacked. It is very simple and may make a suitable small stove to try out hot tenting if your budget is zero.
The biscuit tin tent stove
Burn chamber
This tent stove needs two 40mm diameter holes cut in the biscuit tin lid. Elsewhere, hand cutting methods are described if you are not lucky enough to have a suitable punch for this job. One hole is for fitting a stove pipe and the other receives a short fuel stick holding tube that becomes a downdraft gasifier when the stove is lit.
Tent stove flame guide
The flame guide can be made from scrap roofing iron. Old fashioned iron is relatively soft and easy to work with. Modern roofing iron is much harder and brittle and is much harder to work.
With this biscuit tin tent stove design it was simple to extend the ‘foot’ of the flame guide and cut a curve on it to fit across the entire bottom of the large (and hottest) compartment of the combustion chamber. It holds the flame guide securely and provides some insulation to the bottom of the stove hottest first chamber.
The enlarged flame guide foot also can act as a heat sink for the hottest parts of the guide (when covered with an insulation layer as described next) and thereby extend it operational life.
At the end of the the flame guide that will be placed directly below the down draft wood gasifier (left end) the charcoal combustion will reach 1,000C+. I have added a scrap of iron to the flame guide to form a curved wing that will protect the wall of the biscuit tin from the high temperature and strongly oxidizing conditions that occur in this zone.
Fitted flame guide
The flame guide should be made to just squeeze into the biscuit tin by stretching the circular opening a little to allow the guide to clear the beading that is formed around the opening of the tin. A slightly oversized flame guide can simple trimmed to fit perfectly.
Alternative flame guide sheet metal
If the stove is intended for backpacking the flame guide could be made out of a much lighter tin plate from a discarded food can or stainless steel from curbside rubbish as shown below.
Soil and ash base cover
The base of the burn chambers can be covered generously with sand or soil and ash to provide insulation for the bottom of the stove. As the burn progresses, a deeper layer of ‘fluffy’ ash will form and this will add to the insulating effect. The insulation of this layer causes more heat to be distributed to the stovetop and less heat to be transferred to the bottom of the stove.
Stove base insulation and thermal mass
The heavy soil component of the above-described insulation layer has other benefits. It gives an otherwise very light stove thermal mass. This means that it will make the stove burn better during fueling ‘glitches’ and also recover quickly when refuelling is neglected.
There is a very slight negative impact in that this extra thermal mass makes the start-up-from-cold a little less delightfully fast than my stoves without much mass. However, the gain in the robustness of the combustion more than offsets this small loss.
[Add a video of biscuit tin stove start-up.]
The layer provides considerable protection to the stove bottom and in doing so it reflects more heat to where it is most needed. Also, the soil gives the stove a lot more thermal mass to maintain the stove pipe draft. This means that it will make the stove burn better during fueling ‘glitches’ and also recover quickly from refuelling is neglected. “Another low mass tent stove that can have mass added when the carrying is done”
Size matters
When compared with my benchmark’ KISS tent stove (137mm dia) the biscuit tin stove was a little slower to start up. I think the extra thermal mass of the heavy flame guide and soil plus ash base layer was the cause of the slowness, but it was not a problem.
On the other hand, extra mass was a great benefit for burner stability after startup. “All good”. The biscuit tin stove produced lovely trouble-free warming heat and could slowly boil water. However, when compared with my KISS tent stove, I could tell that the biscuit tin (175mm dia) was less powerful. Or maybe more correctly, it had less intense or concentrated heat for cooking and radiant heat for warming bodies. “Nevertheless, this cheap and hot tent stove would be a good first try at hot tenting.”
A large biscuit tin tent stove- finding the breaking point
“In a funny way, I don’t consider an idea has been properly explored until the breaking point is found!” Consequently, I made a larger biscuit tin stove (240mm dia, shown below) to see what would happen. The tin for this experiment was purchased from amoungst many for the princely sum of $1.00.
When compared to the ‘benchmark’ KISS tent stoves cooktop area, the biscuit tin cooktop area ratios were 1.6 and 3.1 respectively for the small and large tins respectively. I expected that when using the same burner and stove pipe combination on these different sized stoves, that the large increase in the stovetop area would cause progressive lowering of the stovetop temperature.
The following night time photos should provide a simple visual indication of the relative radiant heating power of the three stoves. (I have not directly measured temperature on all three stoves on a fair comparative test. I will do so and add the results when available.)
The photos below were taken to show each stove at its peak temperature performance. I think you could imagine which stove you would like to have near you in a small tent in a snowy winter wonderland. “I know I can. However, I think you could also imagine that any one of them would be welcome in the tent on a freezing night.”
Stove metal- a confounding factor
Apart from the increased stove size in the above comparison, the stainless steel of the KISS tent stove is much less conductive than the mild steel of the tinplate of the biscuit tins. I think this difference may also be another contributing factor that makes the smallest stove hotter than the others. This, at first, may seem counterintuitive. However, I discuss this in my post on micro tent stove design for strong radiant heat and robust draft.
Conclusion
This biscuit tin tent stove is quick and cheap to make and with care, it should provide several weekends of hot tenting. Keep the stove small (175mm or less) to get the best heating power and the fastest cooking. It should give you a taste of hot tenting pleasures. You may get hooked and wish to make make a hotter, lighter, more durable and more compact KISS tent stove that backpacks easily within its own pots and can also turn into an outdoor fast cooking blower or alcohol stove and have a much longer service life.
Tim
Addendum
If this post interest you, you may be interested in my other tent stove related post:
A larger free tent stove from an oil drum
An improved free tent stove from an oil drum
A durable and compact backpacking KISS tent stove made of stainless steel
Just beautiful.
Already sourced a cookie tin.
Thank you.
Hi Huck, For your first try, it would probably be best to stay with a diameter not much bigger than 170mm. It will give more satisfying direct body heat in a small tent. On the other hand, if the stove is for a tiny home where you are heating the insulated space the larger stove diameter might be more effective. I just don’t know. You could try one of each and let me know?
Tim