The hexamine tablet – the ultimate ultralight fuel for the jungle?
By Amir Che
It is the staple of all armies around the world, is well known to campers and can be found almost all around the world. The hexamine fuel (also known by the following names in Malaysia : Hexi blocks, Solid fuel and “Lilin askar” English: Soldier’s Candle) has been used all around the world for decades since it’s invention in 1936.
I’ve personally seen it being used by anyone from professional soldiers to school children out hiking here in the mountains. I’ve used it extensively during training and there’s nothing like the smell of hexamine blocks burning, especially since it usually means foods almost ready! (a hot brew to boot!)
So what exactly is it, and is it the best fuel out there for our hot and humid jungle environment?
Hexamine tablets comprises of hexamethylenetetramine (hence the name) and 1,3,5-trioxane. Made into blocks, the hexamine tablets are very energy dense, burns smokelessly and doesn’t leave any ashes. It is also very lightweight, in comparison to many other cooking options out there for the hiker. It usually comes with a small stove, made almost specifically for army issue mess tins but can also fit other pots and pans if need be.
They are usually used to heat precooked food, such as those found in army ration packs (or MREs – Meal-Ready-to-Eat). It is, being a heat source, can be used to cook meals, but controlling the heat takes a bit of skill.
|AMIR’S PRO TIP: Do not use the whole block when cooking. Always break the hexamine tablet to smaller pieces (I usually break them into two parts), then burn them as needed.
Hexamine tablets takes a while to light, as anyone who has ever used them will testify. Using a small piece of hexamine, keep a fire to it until you see the hexamine tablet starts to look like its melting. The hexamine block will start to catch the fire at this point but is still pretty fickle (at this point, any wind might blow it out.) Leaving it until it starts to properly catch, the hexi block can then be put onto the stove.
At this point, the hexi block is almost windproof and only a really strong wind can even have a chance to blow it out. Most of the time, I’ve seen wind only add more oxygen to the fire, turning it into a furnace!
Some people have stated that hexi blocks is hard to re-use/ save. Nonsense! If you’ve already cooked your meal, and the hexi is still burning, then extinguish the fire and allow time for the hexi block to solidify and cool before picking it up and storing it.
The advantage of Hexamine blocks over other fuel types and sources is firstly, it’s robust. Other fuel sources such as gas canisters have pieces that can break easily. The gas canisters available in Malaysia are of two types : The puncture type gas canisters or the aerosol type containers. These two types have parts that can break rather easily if it’s being bashed about in your rucksack as you make your way through the undergrowth. The burners they rely on can be clogged if not properly taken care of. Gel or other liquid fuels needs to be carried in a special container.
Secondly, the hexamine block is simple. It has no moving parts, no ancillary pieces to carry. Just light it and away it goes!
Thirdly, it’s weather-resistant. The hexi block is impervious to bad weather. I’ve lit hexi block in frozen conditions at -0OC, I’ve lit then on top of mountains with high winds, and I’ve lit them after they’ve become wet from my rucksack being soaked through by rain. Jungle conditions are primarily wet (from the rain) and humid. Dry tinder can be hard to come by , making finding firewood difficult. Nearing the mountain tops, the wind tends to pick up a lot, making gas cookers more susceptible to being blown out. The ability of the hexi block to work in almost any weather condition gives it an extra edge in this respect.
Fourth, they’re cheap…-ish. Hexi blocks are cheaper than most other camping fuel source available. At around RM 4 (or approximately USD 1.5) for a pack of 8 blocks without the stove, they are pretty hard to beat in terms of price. An 8 block pack can last anywhere between 4 to 8 times cooking (depending on how you make it last, weather conditions etc.), so you might need a few for a long expedition.
Lastly, they’re light. For those who has ever carried any amount of weight long distances, you will know that every gram will feel like kilograms as your energy gets sapped. Thus, it’s always important to get the lightest equipment you can, and it’s no different for the source of fuel that you choose to carry.
Granted, they’re not without fault. When cooking with hexi tablets, they tend to let of a fume. I’ve been told that hexi tablets are toxic, and one should take care when handling them. You should try and wash your hands after cooking with hexi tablets.
Hexamine tablets also tend to leave a dark, black residue on any pot or mess tin that you cook in. In training, we were taught to keep our mess tins clean to avoid any food poisoning. Any cooking pots that are used should be cleaned thoroughly from this black residue.
All in all, I believe that the hexamine fuel table presents a good choice as a fuel source for campers and hikers. Its advantages outweigh a lot of the competition, especially to those looking to save a few Ringgits or are just getting into hiking. There are more technical stoves out there, but the hexi will always remain a favourite of mine for use in the jungle.
- Gives out fumes (which can be nauseating)
- Leaves black residue on cooking pot, which is hard to clean
Till later fellas! Have fun out there!