Josef Borde (b. 25th October 1904 - d. 2nd January 1978) was born in Böhmen, Czechoslovakia. Following the completion of his training as a watchmaker, he then emigrated to Zürich, Switzerland. He was an very experienced mountaineer and along with his precision engineering background, led to him to design and subsequently patent the aluminium Borde Flask Cooker (and of course the famous Borde gasoline stove), both of which began being manufactured around 1950. From my research, it would appear that the production of the Borde Flask Cooker likely ceased in line with the passing of Josef Borde in 1978. This Borde Flask Cooker has never been used and has very fortunately retained the original SIGG manufacturer paper-carded ‘swing tag’. I have copied the original Borde Flask Cooker patent document’s first page and schematic from @Knee ’s excellent 2023 post… Flask Cooker Borde …and generated an AI translation. It is interesting that whilst this Flask Cooker was manufactured by SIGG, their usual commercial ‘SIGG’ trademark stamp (as seen on the bottom of their aluminium fuel bottles for example) is entirely absent. Instead, the stamping on the bottom of the of the Flask Cooker stove body is ‘+SF’ as shown in the picture below. It appears the ‘+’ serves to denote the Swiss national emblem and ‘SF’ stands for ‘Schweizerische Federal’. This signifies a Swiss Government contract for the manufacture of the Borde Flask Cooker. This aligns with the known fact that the Borde Flask Cooker was issued to and used by the Swiss Army. The intricately formed 2-piece metal ‘wire-securing clip’ is shown below, having been moved from its securing position over to where the ‘nested’ cup and flask can be removed from the Flask Cooker body. Josef Borde’s original concept for a simple but very effective lightweight 3-piece cooker set came about from his very extensive Alpine mountaineering experience accrued ostensibly in the 1920’s and 1930’s. The main wire-securing clip is positioned such that the connected ‘inner’ wire section can have its central ‘elongated loop’ inserted into the receiving hole in the cooker body, as shown. When the flask is placed into the cooker body, this wire loop then acts as a ‘stop’, keeping the flask’s bottom at the optimal height above the fuel source - which as the patent document confirms, would be a solid fuel heating tablet or similar. The wire loop has an additional function in that it assists the main wire-securing clip to ‘lock’ into place when the Flask Cooker is packed away. The flask’s cork stopper acts as a very functional pressure-release ‘valve’. Not that you would wish to be too close to the cork when it decided to launch itself! The design of the 0.4L drinking cup is such that bottom lip of the top section sits against the top lip of the cooker body which then automatically positions the bottom section of the cup at the optimum height above the fuel source. The stove ‘cut-out’ obviously allows placement of the solid fuel heating tablet. Now we come to the use (or rather the non-use) of a No.33 Borde gasoline burner with the Borde Flask Cooker No.6. Taking a close look at the instruction sheet from my No.33 Borde gasoline stove which is posted here, some interesting facts emerge. A No.33 Borde gasoline burner is not shown being used with the Flask Cooker. Note the capacity specification of the Borde Flask Cooker No.6 is listed as ‘¾ litre’ (as confirmed above). The subsequent page states the following (highlighted below) ‘The burner is perfectly easy and safe to handle and can be used for all cookers from 1 to 3 litres capacity. The cooker should have an aperture of 6cm x 6cm for the insertion of the burner.’ Therefore, since the ¾ litre capacity of the Borde Flask Cooker does not match the required 1 to 3 litre capacity required by a No.33 Borde gasoline stove, this would be the reason why they were not shown working together. An additional point to mention is that the cooker body cut-out would need to be widened to allow the No.33 burner through. A final thought. For those who may be intrigued nevertheless to use the two together, just remember that to all intents and purposes, aluminium does not usually glow red before it melts…. Pharael. Post script: These aluminium lids (one with the holes is used for straining) are a non-Borde addition which fit the drinking cup nicely. I added a black silicon key cover to each of the lid’s small metal ‘handle’ which makes removing the lid a cinch.
Nicely presented! I have seen flask cookers where the "slot" is narrower, I imagine for a META style fuel tablet rather than the Borde. I didn't have the heart to chop it out larger Alec.
Great post! It’s full of useful details. I agree that it's a very well-designed and practical device. I couldn’t resist the temptation, so I enlarged the hole to test it with a Borde burner. Fortunately, there were no unpleasant consequences .
Someone on here, a long time ago, warned me not to use my Borde with the flask kit because it will melt the bottom of the flask. He spoke from some hard-won experience. He was also looking for a new flask set.
I have one of these as I used to collect mess kits and stuff like that. I used a homemade alcohol stove from a candy tin or tablets in this thing...but I have seen youtube videos where bushcraft types will pack these with wood and pine needles and used them like a pot cooker....lol
Great post on one of my favorite cookers. I bought one in Hiroshima in '76 for a Fuji attempt. I used Japanese canned heat. The type I bought burned fiercely for a short duration. Enough to heat the cup water. I added a cocao packet and 1 C-Rat instant coffee. It was good but I was out of fuel, and hadn't brought more cans. I later bought a Trangia burner from REI. That seemed to be the ideal heat source, except it got pretty hot, and extinguishing the flame was dicey. Sometimes the butt of a 750 ml bottle on the top of the Trangia holes works, but you still may have to blow out the flames. Using the Borde as a stick burner I would not advise, as the aluminum can't take the heat. I bought a few different remote cannister butane burners but they are always too big for the interior space. The Swiss military surplus <<Nottkucher>> fits inside, but I have not tried burning one yet. It's like Sterno, but not red. Esbit or generic hexamine tabs should be a good heat source. [Haven't tried them yet,] Possibly Meta tabs were still available when these came out. Interesting to infer that the designer never intended for his coil burner to be used with the Flask Cooker. They almost seem made for each other. I still have my original, plus two more ''unfired'' FlaskCookers.
@Rangie - Thanks very much. It is interesting that the Flask Cooker was included on the Borde operating instructions - clever advertising perhaps on a number of levels? Pharael.
@Remus1956 - Ahhhh those bushcraft types…I count myself among them! In that regard, as you know, I am a Kelly Kettle man. Pharael.
@SveaSizzler - Thank you! I take it you are a fan of the Borde Flask Cooker then…! I suspect it was clever advertising of the Flask Cooker for it to be included on the Borde operating instructions. If one did use them together which subsequently ended up with the occurrence of an adverse thermal event, well…the ‘small print’ was there… Pharael.
