Tuesday, February 24, 2015

Canister Stoves - MSR WindPro II

Advantages

  • Remote canister
  • Canister can be inverted
  • Windscreen

Disadvantages

  • Separate canister stand
  • Long boil time
  • Fuel consumption

Notes

  • Packed weight: 10.5 oz. (297 g)
On the original version of the WindPro stove the canister attachment did not swivel and inverting the canister was not very easy or practical. The WindPro II, has been modified to allow for the easy inversion of the canister, and a separate stand is supplied that attaches to the canister valve and keeps the canister in the correct position while inverted, giving access to the valve control.

I really dislike the separate stand. The separate stand just feels cheap! You attach it and detach it every time you use the stove. It is a non-folding, rigid three legged, space consuming "plastic" piece that you must also carry in addition to the stove. Being a non-metal item may make it weigh less, but it is a non-field-repairable point of failure for the stove. At least with a metal stand, you could straighten the item if it were crushed.

What makes the WindPro II better than a top mount canister stove such as is exemplified by the Optimus Crux? Two major items make the WindPro a better stove system.

First, the remote canister allows for the addition of a windscreen around the stove without heating the canister..

Second, the ability to invert the canister gives a wider range of temperature for operation. You still need a warm canister for stove ignition, but as soon as the stove is lit and hot, you can invert the canister. The pressure from the propane will force liquid contents of the canister through the fuel line and the stove then functions as a liquid fuel stove. Since very little conversion is occurring inside the fuel canister, the canister does not self-cool as quickly and you are not simply burning off the 20% propane. Note, you must have either a warm canister or enough propane in the canister to light the stove, or in liquid fuel stove terms, prime the stove. Keeping the canister inside you coat prior to using, or in the bottom of you sleeping bag during the night (if you are cooking breakfast) will to the trick.

In the inverted orientation, you will notice a lag between the time you turn off the stove, and until the stove actually goes out. This is similar to a regular liquid fuel stove. You will also notice some loss of flame simmer control.

Do I recommend this stove? No. I my opinion there is a better designed and a more efficient stove, both in terms of boil time and fuel consumption. I will discuss, in my opinion, a better stove next.

My use and testing show that the stove boils 2 cups (~500 ml) of water using a MSR Titan Kettle in 4 1/4 minutes using .4 oz. (10 g by weight) of fuel.

Monday, February 23, 2015

Canister stoves - Optimus Crux

Advantages

  • Small
  • Folding
  • Stores in concave bottom of 8 fl. oz. canister
  • Larger burner

Disadvantages

  • Instability - Center of gravity (with full pot) vs. footprint diameter
    • Worse with 4 fl. oz. canister
  • No windscreen

Notes

  • Mounts on top of canister
  • Consider a stabilizer stand
  • Pack weight: 3.8 oz. (108 g)
The Optimus Crux is similar to almost all canister stoves. The stove mounts directly on top of the canister and uses the canister as the base/stand. This style of canister stove suffers from the inability to use a windscreen. Using a windscreen will also reflect heat back towards the canister which is very dangerous.

This is the first canister stove that I bought. I had a trip planned for Havasupai, in the Grand Canyon. With summer temperatures and little wind in the Grand Canyon I had decided that I wanted a smaller, lighter stove. After talking with several people and doing some research I decided on the Crux. I liked the size of the burner head, and the fact that the stove came with a "pouch" that stored the stove in the concave bottom of an 8 fl. oz. canister.

After purchase, testing only re-enforced that I had made a good decision. My three day trip in to the Grand Canyon proved the stove even more. This was my mainstay summer overnight camping stove for several years, until I spent way too much money and purchased a MSR Reactor.

At the time of my purchase, I did not know that you could not use a windscreen with this style of stove, and none of my research mentioned the danger of using a windscreen with a canister. For my trip into the Grand Canyon the Crux performed flawlessly and since there was never any wind in the canyon, I never noticed the lack of a windscreen. Several weeks after the Grand Canyon trip, I took this stove on a solo overnight trip to one of my favorite fishing holes. At this particular location a light wind is always present especially in the morning and evening as the nearby valley warms and cools. That evening as I was attempting to boil water for my evening meal, I became very aware that upright, top mount canister stoves are susceptible to wind. I had to move my meal preparation area to find a more sheltered location.

On my return from the above trip, I started my research into windscreens for the Crux. I liked the stove enough, that I did not want to change to something else. At the time, no one made a windscreen for an upright top mount canister stove. Today is a different story. Optimus now makes a windscreen for the Crux and Crux Lite. Of course they have made the windscreen specifically for use with the Optimus Terra Solo or Terra Weekend HE pot, but I have found that the Titan kettle that I own is almost exactly the same dimensions as the Solo pot, and functions nicely with the windscreen. The only thing I do not like about the windscreen is it fixed size, and I have difficulty packing it since it is rigid. The windscreen does pack around the Terra Solo and Weekend pot very nicely.

You can also purchase a stabilizer stand for the canisters. These give a much wider footprint. I have found that not all the canisters have the same outside dimensions. As a result the plastic legs similar to the Optimus Canister Stand or the JetBoil Fuel Can Stabilizer work best for the matching brand canisters. The MSR Universal Canister Stand works across every brand canister that I have been able to test (Primus, Optimus, JetBoil, MSR, and several other less know brands).

Do I recommend this stove? Yes, I really like this stove, and the windscreen is not a requirement.

Note: The Crux Lite is a non-folding version of this stove which is 11g lighter. I prefer the folding version because it stores in the concave bottom of an 8 fl. oz. canister.

My use and testing show that the stove boils 2 cups (~500 ml) of water using a MSR Titan Kettle in 3 1/2 minutes using .3 oz. (by weight) of fuel. With the Terra Weekend HE pot, the boil time is 2 minutes, but pot weight increases significantly in respect to the Titan Kettle.

Sunday, February 22, 2015

Comparing Stoves and introduction to canister stoves

One of the things that I have realized as I have been writing about some of the stoves I have purchased and used of the the last few decades was that I needed to put all my information on one page. As a result I have built a spreadsheet comparing weight, fuel consumption, boil time, etc. I now need to build a page showing that information. I am in progress on that page, and it will show up here in the near future. I am still trying to design how to compare the different types of stoves, namely; Alcohol, liquid fuel, and canister.

I have never been a fan of canister stoves. My dislike of canister has it roots in two things. First, the inability to know how much fuel remains, and the associated need to either carry a spare canister, or a new canister. If you always carry a new canister, you end up with a shelf full of partially used canisters.

Second, canisters suffer in performance and/or failure in cold temperatures and with altitude. If I were only a fair weather backpacker and I did not regularly backpack in an area where getting above 11,000 ft. was difficult to avoid, then maybe I would not distrust canister stoves so much.

Do I own some canister stoves? Yes, I have several.
Will I be objective in discussing canister stoves? Yes, canister stoves have their place.

A major advantage of a canister stove is the "instant on". A canister stove is a "light, adjust flame, and use" stove. Setup time is minimal. Another advantage is that the stoves are generally lighter, and smaller than liquid fuel stoves. Canister can also be significantly cheaper in price than a liquid fuel stove. Note however that canister stove systems, such as; JetBoil, Reactor, or the WindBoiler are generally more expensive than most liquid fuel stoves.

My next few post will be around the few canister stoves that I own and have used.

Before I begin I want to say a few technical things about canisters.
  1. Butane requires a temperature above 31º F to convert from liquid to gas
  2. IsoButane requires a temperature above 11º F
  3. Propane converts a -45º F
  4. Canisters containing a mix of butane, isobutane, and propane generally contain 20% propane
    1. MSR IsoButane is 80/20 mix of Isobutane and propane
    2. JetBoil JetPower is 80/20 mix of Isobutane and propane
    3. Primus Power Gas is 50/25/25 mix of Butane, Isobutane, and propane
  5. Canisters are unsafe at temperatures above 120º F. Bulging and/or rupture and explosion are likely. The real warning here is that you should never use a windscreen that encloses both the stove and canister together!
For temperatures below freezing, using a butane/propane canister with an upright canister stove. Only the 20% propane fuel is available, and when that 20% propane is consumed, the stove will cease to function with 80% of the fuel still in the canister. Inverted canister stoves are designed to fix low temperature canister issues and for the most part are successful. You should note that the process of converting from a liquid to a gas causes cooling. This cooling occurs inside the canister. So while the butane will quit converting a 31º F, outside temperature may be will above 31º F. In fact, I was using a canister in 43º when the stove went out. The canister still had some fuel, but until I warmed the canister, (by placing the canister in a shallow bowl of tepid water), I was unable to relight the stove.

Liquid Fuel - Optimus SVEA

Advantages

  • No pump
  • Proven design
  • One piece
  • One moving part (the valve)

Disadvantages

  • Small fuel reservoir
  • heavy

Notes

  • White gas only
  • Integrated fuel reservoir
  • Pack weight (w/o fuel): 22.2 oz (629 g) w/cup, 19.6 oz (557 g) w/o cup 
  • Include "pot" extremely small
Originally introduced in 1955, this stove remains essentially unchanged. The only noticeable changes are the internal jet cleaner, valve angle, and the modifications to the valve key tool. The original valve had a downward angle from the stem. The new valve is perpendicular to the stem. I assume the change in angle is to facilitate the internal jet clean. The changes to the key are of little importance since the key is only used to turn the valve and has cut outs to fit the jet and hex nuts for maintenance.

I bought this stove for a couple of reasons.

First, this stove remains essential unchanged since 1955 and is still available today. How many stoves can boast that longevity. I just wanted one. Since I have more advanced stoves, I doubt that I will every carry this stove into the back country.

Second, this stove has no pump and bridges the gap from the simple alcohol stove, to the pressurized liquid fuel stoves. One of the drawbacks to alcohol stoves is their susceptibility to wind. Without pressure behind the flame, the flame moves around like a flame on a candle. One of the drawbacks to liquid fuel stoves is the pump. A pump failure is catastrophic. I have never had a pump fail, but it is a complex piece of the stove. The SVEA does not have a pump, yet works as a pressurized stove. As I do presentations to groups about backpacking, I like to have this stove that bridges the gap.

In the most simple terms, the SVEA uses heat from the burn to self pressurize. Like other liquid fuel stoves, you must prime the stove. The integrated fuel reservoir is heated with the priming, causing pressure to build. The burner is also heated converting the liquid to gas and allowing the stove to produce a good blue flame which perpetuates the process. Word of warning. The stem and valve get very hot and if you leave the key on the valve, that heat is transferred to the key. You will burn you fingers adjusting the flame! Always remove the key from the valve after making any adjustment.

The SVEA burner is the classic inverted bell similar to the DragonFly and Nova stoves.

The noise level is similar to the Nova stoves, which produce less noise than the DragonFly stove. The SVEA also has a "buzz" beside the classic jet engine sound.

The included aluminum "pot" is too small to be of any value other than a lid to the packed stove. Since there are not "parts" for the lid to hold in place, that does not even make a good reason to carry the "pot" as a lid.

One thing to note. The stove has performance issues with older fuel. With newer pressurize stoves you will probably not notice the performance difference using older fuel unless you use a stopwatch to time your boils. With the SVEA you will notice that the stove does not produce a consistent flame and tends to sputter. I discover this by accident. I had an old fuel container with a few ounces of fuel left in it that was several years old. I used that older fuel in the stove just after I purchased the SVEA. The stove performed so poorly that I was beginning to wonder if I had a bad stove, or if the "cult" like following of the SVEA was just that, a "cult". I finally dismantled the stove, cleaning the jet, the tank, and everything else I could find. I poured in new fuel, and the difference was night and day. The stove performed so well that I wondered what I had done that fixed it. I then had a thought about the fuel, so I swapped out the fuel for the older fuel. Stove went back to not working very well. Changed the fuel out again to new white gas, and I had a functioning stove that performed very well.

With newer and lighter stoves available to me, the SVEA has not yet made it into my backpack. My decision not to carry the stove is all about weight. The fuel reservoir carries enough fuel for a few nights, any longer trip length and you need to carry addition fuel. The extra fuel and bottle make the SVEA even less appealing because of stove and fuel weight. The SVEA performs as well as any other stove, and is uses about the same amount of fuel as my most efficient liquid fuel stoves. It is just heavier than the newer stoves.  For an overnight or for a weekend trip, the SVEA competes very well since no additional fuel bottle is required. Newer stoves require the fuel bottle which raise their weight to be comparable to the SVEA that does not require a fuel bottle (for short trips).

My use and testing show that the stove boils 2 cups (~500 ml) of water using a MSR Titan Kettle in 5 minutes using 2/5 oz. (by weight) of new white gas.

Monday, February 16, 2015

Liquid Fuel - Optimus Nova+

Advantages

  • Four season
  • Fuel efficient
  • Fine grain flame control
  • Non-Plastic pump (durable)
  • Fuel line purge
  • Fuel bottle pressure purge

Disadvantages

  • Weight
  • Non-Plastic pump (weight)
  • Noise level

Notes

  • Multi-Fuel: Optimus Arctic Fuel, white gas, kerosene, diesel, jet fuel
  • Pack weight: 18.9 oz. (535g)
My first impression of this stove was "wow". It is well built. It has a wide set of legs and pot supports. After using this stove several times, my opinion has not changed. I am impressed. The weight is a little high, but to have a stove this solid, I can understand the little extra weight. However, the stuff bag is really odd. It has pockets for the stove, pump, and probably the windscreen. However, the factory folded windscreen does not fit in to any pocket. In fact, the pump really does not fit well, it keeps falling out of the pocket. The whole stuff sack unzips down the side to lay flat. Bottom line, the stove really does not fit very well in the stuff sack. With everything in the stuff sack, I am unable to completely close the opening with the drawstring. No matter how I arrange the stove, pump, tool, and windscreen, it just does not fit! To have a stove that impresses with it's engineering only to have a less than useful stuff sack is just dumb!

The Nova more closely compares to the DragonFly stove because the second jet adjustment is at the stove. The Nova+ modifies the Nova slightly by using the fuel line as the second jet adjustment. While I was initially hesitant about the design, I have really come to appreciate it. Since the fuel line just turns the threaded flame adjustment jet in and out, I see no more of a point-of-failure than either the Nova or the DragonFly. The advantage is that the windscreen does not need to be arranged around the second jet adjustment level. I like the design.

When I first started writing about remote liquid fuel stoves, I mentioned a couple of issues that plague most remote liquid fuel stoves. The Nova+ not only addresses the simmer issue, but also the issue of fuel left in the fuel line after use. Optimus has designed this stove and pump, so that after you are finished using the stove, you flip the fuel bottle over. The fuel line to pump connection is designed to let the fuel bottle swivel. The inverted bottle raises the fuel intake out of the fuel and allows you to burn off the fuel left in the fuel line, and evacuate the pressure from the bottle. Very nice useful feature. You do not have to worry about the fuel spraying in your face when you remove the pump, or the fuel leakage into your pack from the fuel line.

My use and testing show that the stove boils 2 cups (~500 ml) of water using a MSR Titan Kettle in 5 minutes using 2/5 oz. (by weight) of white gas.

Sunday, February 15, 2015

Liquid Fuel - MSR SimmerLite

Advantages

  • Light weight
  • Faster boil times

Disadvantages

  • MSR no longer produces this stove
  • Uses more fuel to achieve faster boil times

Notes

  • Pack weight: 11.5 oz. (327g)
  • Single fuel: White gas
What terrible name for this stove. Luckily I bought this stove for its weight, not for the promise the name implies. Like almost all remote liquid fuel stoves the SimmerLite does not excel at "simmer". If you need "simmer" capabilities you need to look at the MSR DragonFly, Optimus Nova, or Optimus Nova+. From a quick search on the Internet MSR took quite a bit of flack for the inability of the poorly named SimmerLite to actually simmer.

I actually like this stove, but I only use it to boil water (or melt snow). Having previous experience with the inability of remote liquid fuel stoves to simmer, I never thought too much about the name. You know a name is after all just a name. My regret is that one of the lightest liquid fuel stoves is now off the market. Since, I almost exclusively, backpack in North America where White gas is always available, a single fuel stove is not a disadvantage.

The burner technology for the SimmerLite is similar to the WhisperLite.  If you look at a WhisperLite stove vs. a DragonFly stove you will see many differences but the one I am referring to is the burner where the WhisperLite has a typical gas stove type flame spreader, while the DragonFly has a inverted bell with a concave flame spreader. The result for the SimmerLite is a much quieter operation.  The inverted bell and concave flame spreader of the DragonFly make like a small jet engine.

One interesting note is that the MSR Windpro II stove is the canister stove twin of the liquid fuel SimmerLite. So MSR is still making the burner, but just jetting it for canister. Too bad there is not a conversion kit. If the name was the reason they quit sell this stove. MSR should have just changed the name and re-marketed the stove. Luckily the pump is identical to the WhisperLite so if I ever need to replace or repair the pump I can. Since all the seals and O-rings reside in the pump I am also covered with the Maintenance kit.

My use and testing show that the stove boils 2 cups (~500 ml) of water using a MSR Titan Kettle in 3 minutes using 3/5 oz. (by weight) of white gas.

Saturday, February 14, 2015

Liquid Fuel - MSR DragonFly

Advantages

  • Liquid fuel
  • Fine grain adjustable flame
  • Efficient

Disadvantages

  • Weight penalty for adjustable flame
  • Noise level (not quiet)

Notes

  • Multi-fuel is: White gas, unleaded auto fuel, kerosene, diesel, jet fuel
  • Pack weight: 16.8 oz. (475g)
There are two things to note about almost all liquid fuel stoves with an external fuel bottle. I say "almost" because I know of a few stoves that solve either one, or both items. Inverted canister stoves share these same issues to some extent.

First, external liquid fuel bottles stoves are basically designed to boil water. These stoves lack the fine grain flame control required to simmer. Which I discovered on a trip, when I tried to make pancakes. My only excuse was that it was my first extended trip and only my second trip ever with the stove and I just did not think about "simmer" since I usually only boil water for dehydrated food.

With the fuel bottle some distance away from the stove, and the valve controlling fuel flow located at the bottle you can begin to understand the issue. With the valve open, the liquid fuel with pressure from the bottle pushes down the fuel line, then spews through the jet, where it ignites and burns to boil your water. If you close the valve to decrease the flame, less fuel is delivered down the fuel line, and less pressure pushes it. What I am trying to say is that the flame begins to sputter. It does not go out, but it no longer burns at a constant level.

While you can simmer, the stove really functions best at higher flame output.

The MSR DragonFly addresses the flame adjustment issue, and does so very well. The DragonFly adds a second valve at the stove just before the jet. This allows you to leave the fuel valve open to deliver fuel at pressure to the stove, then restrict the amount of fuel delivered through jet controlling the flame. The only penalty you pay, is the slight increase in weight caused by the hardware of the second valve. I measured the weight difference of my WhisperLite International to the DragonFly at 2 oz. (~55g). Note that the stove utilize different burner technologies so the weight difference cannot all be attributed to the second valve.

One other thing to note is that the DragonFly burner technology, shared by many liquid fuel stoves from various vendors, is rather noisy in operation. The WhisperLite uses a different burner technology and is quieter in operation.

Second, when finished using the stove, and you have closed the fuel valve. The fuel line remains full of fuel. While the fuel in the line is a very small amount, it will still seep out. I you immediately pack the stove after use (and cooling) then you may get fuel on something in your pack. You will definitely have a fuel smell in your pack. This is not a major issue, just something to be aware of. There are a couple of stoves that address this issue, and I will discuss them in the future.

My use and testing show that the stove boils 2 cups (~500 ml) of water using a MSR Titan Kettle in 3 1/2 minutes using 2/5 oz. (by weight) of white gas.