A Buyer’s Guide to Bushwalking and X-C Skiing stoves

What type of bushwalker are you? Are you a SuperUltraLightweight Bushwalker who counts every gram “Skin Out” or a good old fashioned Traditional Bushwalker who needs a glass of red to accompany their Fillet Mignon on the gruelling Overland Track?

Well the good news is, that there is a perfect stove to cover both situations and everything in between!

And, if you just happen to be the impatient sort and want the answers right now, the short and sweet version is:

• SuperUltraLight Bushwalkers like Chuck Norris don’t need stoves, naturye will provide everything and of course Chuck would never admit to carrying some nice snacks like Clif Bars and TBD Gels.
• Ultralight and Lightweight Bushwalkers are weight conscious but generally won’t resort to cutting their toothbrush in half and so are happy to use a lightweight hiking stove such as an MSR PocketRocket 2 / SOTO Windmaster / Optimus Crux Lite.
• The Traditional Bushwalker on the other hand just wants something robust, good value for money and easy to use which is exactly where the Primus Mimer and 360 Furno shine.
• The Bush Gourmet needs fine control over their stove from a light simmer to get that brekky poached egg just right through to a roaring heat to seal that fillet steak nicely and so an MSR Dragonfly or Optimus Nova
• X-C Skiers and winter bushwalkers needs a stove that will reliably work in a cold and windy environment, and stove weight is a secondary consideration. The Trangia or MSR Whisperlight are favourite choice amongst X-C skiers.
• DoE, Scouts and the budget conscious just need a stove like the Primus Mimer and 360 Furno which offers great value for money without being too heavy. Cadets on the other hand just seem to like Hexamine stoves.
• For the KISS Bushwalker who only needs to boil water for their morning cuppa and to make their BackCountry Freeze Dried meal for dinner the MSR Reactors or Jetboils are just the ticket.
• The Globe-Trotting bushwalker stuck in some remote village in Kyrgyzstan needs a stove that will burn whatever the locals have on hand but would prefer in general to use a nice clean burning fuel which is where the multi-fuel stoves like the MSR Whisperlite international and Optimus Nova excel.

Stove Types

Canister Stoves

Integrated canister Stoves

Liquid Fuel and Multi-Fuel Stoves

Flame Control

Alcohol/Spirit Stoves

Wood and Solid Fuel Stoves

Fuel Types

Apparently this is a Butane molecule and this is a Vodka molecule. A chemical engineer could simply glimpse at the molecular structure of both of these molecules and know that the energy density of Butane is approximately twice that of Vodka.

But how does this fascinating snippet of information help me as a bushwalker? Well, it means that I only need half the amount of Butane compared to Alcohol to boil the same amount of water and this is something that we’ll delve into further later on.

Butane/Propane/isobutane

In upright canister stoves, the butane/propane/isobutane in the canister is pressurised to a liquid and this “vapour pressure” then pushes the liquid out of the canister which evaporates and turns into a gas as it escapes the canister so that it can burn - these fuels will not burn in their liquid state. In order for the liquid fuel to be pushed out of the canister the vapour pressure of the fuel must be greater than the ambient atmospheric pressure. Vapour pressure of fuel is determined by its molecular structure and temperature.

As an example, propane has a much higher vapour pressure than butane and so it will burn at a much lower temperature of -42°C versus butanes -0.5°C. This explains why most upright canister stoves with a butane canister struggle to get going in the morning when its cold but are On Fire later in the day when it’s warmer. So you’d think that it would simply make a heap of sense to fill the canisters with propane rather than butane right? The problem is that due to the much higher vapour pressure of propane a much thicker canister shell is required, as you would have noticed when you look at the thickness of the propane cylinders used for your BBQ.

So in order to keep the gas canister weight down, butane is the fuel of choice due to it’s much lower vapour pressure.

But Wait! I’ve seen mountaineers use Jetboil stoves at -40°C at the top of K2? Well, there are a few things going on here to help the fuel vaporise:

• A different fuel type such as isobutane may be used or a mix of propane and butane (approx 20% propane) which will increase the vapour pressure allowing the stove to operate at cooler temps.
• At higher altitudes the atmospheric pressure is lower which means that the vapour pressure required to push out the liquid fuel is also reduced as so the canister can be used at lower temperatures. For example at 5500m elevation the atmospheric pressure is half that at sea level which means that butane can be used at temps as low as -16°C compared to the paltry 0.5°C at sea level.
• The mountaineers will take care to use the stove inside their tent where it’s warmer and support it on an insulated surface.
• In really cold situations the mountaineers may resort to various tricks to increase the vapour pressure which are covered in Tips and Tricks.

The table below shows some of the properties of the three fuels used in gas canisters:

Notes:

• 505 hPa ~ 5500m altitude
• 1013 hPa or 760 mm mercury is the average pressure at Sea Level

From the table above you can see that at 20°C the Vapour Pressure is twice that of Sea Level pressure - so happy days - the stoves will work nicely, you will also notice that isobutane will also vaporise nicely at temperatures as low as -11.7°C which is why the premium gas canister fuels such as Jetboil Jetpower, Energy by Optimus and MSR IsoPro all contain a mixture of isobutane and propane. The el cheapo pack of 4x gas canisters that you can get for a few bucks are pure butane and perfect for summer camping but crap when the temperature drops to a few degs.

One thing to be aware of with mixed fuel gas canisters is that the fuel with the highest vapour pressure will evaporate faster than the lower vapour pressure fuel, so as the canister is used up the fuel mixture will slowly change towards the lowest vapour fuel and hence why it the performance of your stove worsens the emptier the canister gets.

The other unfortunate effect that comes into play is that as the fuel escapes the canister and evaporates it also cools the canister further leading to poorer performance. Ohhh the double whammy of mixed fuels and ever decreasing performance as the canister empties.

Of course some of the clever stove manufacturers have gotten around this issue by introducing “micro-regulators” to maintain a more even vapour pressure and developing inverted canister stoves which pass the fuel as a liquid to the burner which means:

• Fuel composition does NOT change as it is used
• No evaporative cooling effects
• Unfortunately for the most part inverted gas canister stoves are not available in Australia due to government regulations. TBD - which ones are available.

Alcohol

Shellite/Diesel

Fuel Efficiency

How much Fuel do I need?

Chart mapping fuel types and weight from 1 day to 20 days

Eco-Friendly Stoves

canister Stoves

• Canister disposal
• Cannot be refilled

Liquid Fuel and Alcohol Stoves

• Reusable fuel bottles
• Exact amount of fuel can be used

Stove Comparison Chart

Need a table here to cover the following attributes. Link to spreadsheet

Attributes:

• weight,
• fuel type,
• up front cost,
• fuel costs
• flame control,
• compactness/size,
• best for

Tips and Tricks

Cold Weather

• Pre-heat your gas canisters either by closely cuddling them all night in your sleeping bag or stuff inside your jacket for 10 mins prior to use. This of course will only get the stove started - if the ambient temperature is cold enough the canister will cool down again and soon start spluttering.
• Place your canister stove on an insulated surface such as a small plywood board, or your plastic plate or bowl to stop it from cooling down too quickly.
• Place the gas canister in a bowl filled with luke-warm water to prevent it from getting cold. DO NOT use hot water as the gas cylinder may explode. The water only needs to be around 20C to get the canister temperature about 0.5C - if you can’t stick your elbow in the water without burning it, then the water temperature is too hot.
• DO NOT use any other methods to warm up your gas canister - it may explode.
• If you use a windshield, do not wrap it completely around the gas canister. Wrap the windshield only half way around and keep the windshield a good distance from the gas canister otherwise the reflected heat from the windshield may be too great and you guessed it, you gas canister may explode.

DIY Stoves

I really enjoy DIY and so here are few links on how to make your very own alcohol stove starting from your basic stove through to the masterpieces created by Tetkoba:

https://www.youtube.com/watch?v=7hdnBHb09iI

https://www.youtube.com/watch?v=OvvdLVUJXZc

https://www.youtube.com/user/tetkoba

Summary