Tuesday, September 9, 2014

How Much Canister Gas Do I Need?

Sometimes I see people bringing a lot more gas for their canister stove than they really need.  Now, it never hurts to be prepared, but really? A 450g canister for a simple weekend trip?  That's potentially a lot of extra weight to pack up a mountain.  Of course we don't want to run out of gas, but let's see if we can't do a little bit better in terms of coming up with an estimate of the gas we might need.
The three standard threaded backpacking canister sizes:
(L to R) 450g, 227g, and 110g.  Note:  Some brands vary as to exact amount of gas.

Now, before I give you my estimates, let me say that my estimates are based on my experience and my style of stove use.  You are your own best estimator.  If you're somewhat new to backpacking, then I'd say err on the side of caution and assume that you'll be doing "complex" cooking and select fuel based on that column from the table below.

What about White Gas?
What's that you say?  You don't use canister gas; you use white gas?  Ah.  No worries.  Check out How Much White Gas Do I Need?

Making Your Own Estimates
As for your own estimate based on your cooking style/stove use style, first you need to get a gram scale. Then weigh your gas canister before your trip.  On every trip, keep track of how many meals you cooked and what type of cooking was involved.  After your trip, weigh the canister again.  The difference between the starting weight and the ending weight is the amount of gas you used.  If you've kept track of how much and what type of cooking you've done, you should be able to start estimating your gas usage after a few trips.

Estimates in the Field
You can also make a rough estimate of how much fuel you're using while you're out on a trip.  See my article in Seattle Backpacker's Magazine, How Much Gas Do I Have Left?

Using Less Fuel 
Whatever you do with a stove, keep efficiency in mind.  There are basic things you can do to use less fuel while you're cooking.  I commend to you my earlier blog post, Canister Gas Stoves -- Recommendations and Efficiency.

My Estimates 
OK, now here are my estimates.  Note that when I boil water, the water is normally around 40F/5C to 50F/10C in temperature.  Significantly warmer or colder water may cause you to use more or less gas.  If you're melting snow, you should roughly double the below estimates.

For a solo trip
Jetboil Conventional Canister Gas Stove
(simple cooking)
Conventional Canister Gas Stove
(more complex cooking)
Grams per day 15 20 30
For two
Grams per day 23 30 45

Now, notice two things:
1.  For a simple weekend trip, for one person, there's no need to ever bring a 450g canister.  A 110g canister should do nicely unless you're doing a lot of extra heating for drinks, dish water, bath water, etc.   A reasonably conservative person shouldn't need more than one small canister of gas for a weekend.
2.  I do not double my estimates if a second person comes.  It's usually more efficient to boil more water at a time.  In other words, if you're going to boil a liter of water, do it all at once.  Don't boil 500 ml, empty the pot, and then boil the second 500 ml.  I'm assuming here that you brought a pot large enough for two people.  If not, then you may need to allow for higher gas usage.

Remember that my estimates are just that, estimates.  Always check that your experience is similar to mine before relying too heavily on my estimates.  Particularly in very cold or very windy conditions, gas usage may increase significantly.

I hope you find this post helpful,


Notes and Assumptions
1.  The figures above assume about 6 cups (approx. 1.5L) boiled per day for simple cooking.
2.  Water temperature is assumed to be around 40F/5C to 50F/10C.
3.  The figures in the table above do not include snow melting.
4.  The figures above assume you know how to operate a gas stove reasonably efficiently (turn it down!  Running on high wastes gas.) and that you've taken measures to shield the stove from wind.
5.  The figures above also assume that you have a pot that is wide enough to catch the flame.  Users of tall, skinny pots with a conventional gas stove will generally use more gas.
6.  Air pressure is assumed to be approx. 900 mBar, the air pressure normally found at about 3000'/900m in elevation.  Stove use at lower elevations may require more gas.  Stove use at higher elevations may require less gas.

Wednesday, May 14, 2014

Drought, Fire, and Stoves (How NOT to end up on the 11:00 News)

I wrote an article for Gossamer Gear on fire safety and backpacking stoves a couple of weeks ago. In light of the extreme fire weather we're having right now and the current fires now burning down in San Diego, I thought I'd post a link (below) here on my blog.

Fire currently (May 2014) burning in San Diego
Drought, Fire, and Stoves (How NOT to end up on the 11:00 News)

Stay safe out there,


Friday, May 3, 2013

Fire Safety -- Alcohol vs. ESBIT?

Currently, there are three active wildfires burning within a one hour drive of where I live.  None of these that I know of were caused by a hiker, but here's one that was:  The Hewlett Gulch Fire (you might want to turn the sound down if you're at work; he cusses under his breath).

From a newspaper article:
The U.S. Attorney's Office ... announced that Fort Collins resident [individual's name withheld] has been cited for causing timber to burn without a permit. [The individual] is accused of starting the fire on Monday, when a stove he was using while camping along the Hewlett Gulch Trail lit the blaze. The stove was a small, backpacking-style stove that burns alcohol.  [emphasis added]
First, let me lay my bias out on the table:  I like alcohol stoves.  I like that they're ultra light.  I like that they're simple to use.  I like that there's very little on them that can go wrong.  I like that they typically burn cleanly and have very little (if any) smell.  I like that they're essentially silent.  I like that I can buy fuel in bulk.  All my "go to" set ups for solo backcountry travel are alcohol based.
A Trail Designs Ti-Tri Sidewinder with an alcohol stove, one of my favorite UL cooking set ups.
Are alcohol stoves safe?
So, first issue:  Are alcohol stoves safe?  I mean is the fire shown in the video above just a fluke?

I think it depends a bit on the design of the stove.  I've personally never used a "tippy" or unstable alcohol stove -- but not all alcohol stoves are equally stable and safe. Note:  An alcohol stove that uses an absorbent wicking material (e.g. carbon felt or similar) would probably be safer, depending on how much alcohol was added to the stove.

I'm always very careful about how I use a stove.  I've never felt like I was endangering the forest (that I love), but realistically not everyone is as careful, and, even if I'm careful, no amount of care is ever 100%.  What if I knock it over?  What if a strong gust of wind tips it over?  Flaming alcohol everywhere.  Sometimes I'll use a full ounce (~30ml) of alcohol at a time.  If spilled, that could spread over an area that I might not be able to extinguish. Some fellow hikers have challenged me on the safety of alcohol stoves.  I have to admit that I don't have a good rebuttal.

There's another hazard besides simple spilling:  refueling.  The flames of alcohol typically cannot be seen during daylight hours.  Stories abound of people trying to refuel a stove that they thought was no longer burning only to have huge flames burst out as they poured alcohol into a burning stove.  And where does that now flaming container go when things catch fire?   Most of us would drop it or throw it, which could be a real disaster.   Always feel for heat with your naked hand before refueling an alcohol stove.  Do NOT depend on being able to see the flames.  See also this cautionary video:

Are alcohol stoves permitted?
Now, the second issue:  Are alcohol stoves permitted?

From the Sequoia National Forest website:
Allowed are: lanterns and portable stoves using gas, jellied petroleum, or pressurized liquid fuel outside of developed recreation sites or campgrounds, but only with a valid California Campfire Permit (available free of charge).
Other National Forests in California say essentially the same thing, and in speaking with others around the western United States, these seem to be pretty much the standard rules.  In other words, alcohol stoves are generally not permitted in National Forests in the western US.  Note:  Always check with the particular land management agency for the area you wish to visit; there are always exceptions to general rules.

So, canister gas, pressurized liquid fuel, and jellied "petroleum" are allowed, but typical liquid alcohol stoves are not.  By "jellied petroleum," they mean Sterno which is actually jellied alcohol not jellied petroleum.  In other words, non-liquid alcohol stoves are allowed.  See also Appendix I, Jellied Petroleum, below.

Is ESBIT safe?
ESBIT on the other hand cannot spill and cannot spread.  ESBIT does not emit sparks or embers that can float off and create a spot fire.  ESBIT does not smolder and then burst back into flame.  Moreover, ESBIT can blown out easily by mouth, much as one might blow out a candle.  I'm not enthralled by the smell of ESBIT, nor do I like the sticky residue it leaves on the bottom of my pot, but absent information to the contrary, I'd have to say that ESBIT is the safer alternative to alcohol for ultralight cooking set ups.
Burning ESBIT in an ultralight cooking set up
Is ESBIT permitted?
Now, is it permitted?  Well, I guess a strict reading of USFS websites might lead one to conclude "no."  However, I feel it is in the same class as jellied "petroleum" (see Appendix I, below).  ESBIT is a fuel that has a) been chemically rendered incapable of spilling and b) can be readily extinguished -- just as easily as a can of Sterno with it's lid.  It's a bit unclear whether the Forest Service is a) just unaware of ESBIT type fuels b) actually intends to ban ESBIT, or c) permits ESBIT since it has the appropriate characteristics (cannot spill and can be readily extinguished).  From a technical perspective, ESBIT is certainly at least as safe as a white gasoline stove and in many ways is safer.  I think there's a bit of gray area here and that the Forest Service should either state outright that ESBIT is banned and why or should state explicitly that it is permitted.  For now, in keeping with the spirit of the regulations, I believe that ESBIT is generally permitted.

Concluding Remarks
I admit that I dislike the ban on alcohol stoves but, grudgingly, I'm getting won over, particularly in times of high fire danger. And ESBIT seems pretty rock solid safe.

The websites of the various National Forests of the western United States are a textbook example of poor writing.   There is a profound lack of clarity on the topic of fire regulations, which I find somewhat shocking since fire is a subject of great importance.  What I've done is to visit a number of National Forest websites.  Only in the aggregate do they start to make sense.  I've quoted the Sequoia National Forest website above since it is one of the clearest.  I believe that I have faithfully rendered the the "spirit of the law" in the above blog post, but there is some room for question.  In the final analysis, the United Forest Service isn't very clear about exactly what the regulations are.  You should always consult directly the land management agency for the area(s) you intend to visit and use a stove.  I do have a general summary listed in Appendix II, below.

Thanks for joining me on the journey,


Appendix I -- Jellied "Petroleum"
All of the Forest Service websites seem to talk about "jellied petroleum."  Jellied petroleum is commonly known as napalm and is used with great effect as a weapon of war; flame throwers use jellied petroleum.  There are no known examples of backpacking type stoves that use jellied petroleum.  So what is the Forest Service talking about?  Let's look at the San Bernardino National Forest's website which has a helpful FAQ section:
Why are jelly petroleum-fueled stoves okay and campfires aren’t?
Gas, liquid, and jelly petroleum-fueled stoves can be extinguished by turning off the fuel source to the stove. Jelly petroleum-fueled stoves can be extinguished by putting a metal lid over the container. This makes their use much safer than campfires. Ashes or hot briquettes can blow outside of the fire pit; these embers can easily start a wildfire. Also, visitors might discard ashes or hot charcoal briquettes before they are completely cool, which could cause vegetation to ignite later after they are gone. Wood, charcoal, or any solid fuel fires are not allowed within the San Bernardino National Forest outside developed campgrounds, picnic areas, yellow post sites, and special use permitted sites in agency-provided fire rings or designated sites at any time of the year.  [emphasis added]
Looking at the above and at other National Forest websites, it becomes clear that they mean Sterno type fuel, which is jellied alcohol not jellied petroleum.

The Cleveland National Forest's web page on Wilderness areas is even more explicit, mentioning the Sterno brand by name:
Campfire, barbecue or hibachi use is not allowed. Propane or sterno fuel stoves are allowed.  [emphasis added]
Notice that the above only mentions propane and sterno.  Does this mean that butane stoves are illegal?  How about white gasoline?  Kerosene?  This is what I mean when I say there is a profound lack of clarity on the topic of fire regulations. Again, one must take the various National Forest websites in the aggregate in order to make sense of them.

Appendix II -- Key Regulations Summary
As I mentioned in my concluding remarks, above, I've visited quite a number of National Forest websites.  If one reads enough of them, in the aggregate, they begin to make sense.  Regulations vary some forest to forest, but generally the below are true.  These regulations are from California National Forests, but regulations in other western National Forests are similar.
  • Backpacking stoves (of any type) are considered by the US Forest Service to be a form of campfire.
  • In the state of California, a California Campfire Permit is generally required in order to operate a backpacking stove.  In some areas, a Wilderness Permit is acceptable in lieu of a Campfire Permit.
  • Pressurized liquid petroleum stoves with a on/off device or valve are generally permitted.   Example:  An MSR Whisperlite stove is permitted
  • Canister gas stoves with an on/off device or valve are generally permitted.  Example:  A Snow Peak Gigapower stove is permitted.
  • Jellied alcohol stoves are generally permitted.  Example:  A Sterno stove is permitted. ESBIT type fuel is not mentioned.  From a technical perspective it has the same characteristics as Sterno (cannot spill and can be easily extinguished), but ESBIT is a bit of a gray area.  I believe ESBIT is in keeping with the spirit of the regulations.  Ask any two different rangers and you'll probably get two different opinions.  At the very least, it's safe from a technical perspective and won't start a wildfire.
  • Liquid alcohol stoves are generally NOT permitted.  They probably are permitted where wood fires are already permitted, but the National Forest websites aren't particularly clear on this point.
  • Wood stoves are generally NOT permitted except where wood fires are already permitted.

Appendix III -- Other Fire Regulations
  • From the Mendocino National Forest website:  "Permits must be signed by an adult eighteen years of age or older."  Apparently, fires are prohibited unless a permitted adult is present.
  • From the Angeles National Forest:  "During high fire danger, additional fire restrictions may be imposed. Before your visit, check with a local Forest Service office for current fire restriction information."
  • From multiple National Forests:  "Clear all vegetation in a five foot radius" and "a shovel is required to be present."  How much the shovel regulation is enforced in backcountry areas is subject to question.  My assumption is that a potty trowel will be sufficient.  A five foot radius seems a bit excessive for a backpacking stove and is hardly a "Leave no trace" practice, but that's what the regulations call for.

Wednesday, May 1, 2013

Blog Status, 1 May 2013

Personal News
Out of work again.  Sigh.  In my industry, IT, it seems that most work these days is project based work.  I just completed a four month contract where I was working sometimes seven days per week, sometimes to midnight or even later, but now I'm unemployed.  Such is life.  At least the project was successful.

I'm ready for a break, but I hope I'll find work soon.  The extra time will hopefully help me get to some posts I've been wanting to write for some time now -- and allow me to do more hiking.  Because of work, I've really had to curtail my hiking trips, particularly in March.  :(

Recent Hiking
I did get out this past weekend to the San Gorgonio Wilderness in Southern California.
Yours truly, in the San Gorgonio Wilderness
I spent some time in a seldom visited corner of the wilderness.  It's great that there are areas like this that are visited by relatively few but yet are close to a major urban area like Los Angeles.

You can see my trip report, if you're interested:  East Barton Flats to Grinnell Ridge Camp.  I had a great time exploring a cross country short cut and checking out a hidden and generally unknown spring -- a valuable resource in a dry area like Southern California.
Hidden Mosquito Spring
A Trail Ambassador
I've become a "Trail Ambassador" for Gossamer Gear, an ultra light equipment company.
So, what exactly is a Trail Ambassador?  It's a collaboration between an individual such as myself and Gossamer Gear.  Basically, I get to try out Gossamer Gear products and in return Gossamer Gear gets some exposure.  People who know me know that I've been trying to lighten up (a lot!) in terms of my carry weight on trips over the last half dozen years or so.  I'm excited about forming a mutually beneficial relationship with a great gear company whose products I've already been using for several years.  Can you spot the Gossamer Gear logo on a piece of my gear in my recent trip report?  :)

The only down side perhaps is that Gossamer Gear really isn't a stove company, so I probably won't be doing a lot of stove reviews on their gear.  I will be using their packs, accessories, etc, and hopefully you'll see them crop up from time to time in my posts.

The State of the Blog
Adventures in Stoving is doing well.  Around the end of February,  Adventures in Stoving passed the half million mark in terms of site views.  That means that over 500,000 people have come to view the information presented here in just a little over two years.  I think that's pretty good for an individual's hobby blog.

Let me share a little graphic with you:
The above is Google Blogger's monthly count of visits to Adventures In Stoving.  I started in January 2011.  Things got off to a slow start, but by fall, 2011, readership had climbed to over 40,000 per month.  I then lost a job that I had held for 20+ years in January 2012.  I perforce accepted a job that required me to drive over 100 miles (160 km) per day in Los Angeles traffic.  My blogging suffered and so did readership.  In 2013, I got a new project to work on, one that was much closer to home.  My blogging picked up again and readership is now slightly above where it was when I got that distant job.  I thank you for hanging in there with me.

With gratitude and appreciation,


Wednesday, April 17, 2013

Canister Gas Stoves -- Recommendations and Efficiency

I got a note recently, below.  I responded individually, but there were some good questions, so I thought I'd expand just slightly and turn it into a blog post.
Hi Jim, 
It was great meeting you at the GGG at Henry Coe [State Park].  Just wanted to ask - what's your current best (good fuel efficiency, low CO emissions, low weight, etc.) sit on top canister stove, and your current favorite remote stove (the Kovea Spider or other)?  Been narrowing down stoves and cooksets and really appreciate your advice.  And for remote stove, what do you use for your windscreen, a Caldera Cone or other?

Remote Canister Stove Recommendation
The remote canister stove is easier for me to answer because I have such a clear favorite:  The Kovea Spider.  It's a very compact, durable design, and it's a design that just makes sense.  It can be run with the canister upside down for cold weather use.  I really like this stove, but, unfortunately, I don't have carbon monoxide (CO) numbers for it; that's beyond the scope of my capabilities.

The MSR WindPro is also very good, but the WindPro is not nearly as compact.  For a larger group (more than three), I might choose the WindPro since it's wider pot support span will support a little bit bigger pot.

The Kovea Spider, left.  The Kovea Supalite, right.  Both excellent stoves.

Upright Canister Stove Recommendation(s)
And as for upright canister stoves, what would I recommend?  There are an awful lot of good ones.  In terms of efficiency, it's generally more about how you use the stove (see below) than it is about the stove itself.  I happen to like the Kovea Supalite (~56g/2.0 oz depending on the version).  It's reasonably light, reasonably compact, and has good pot stability.  You can get lighter, but I think the pot stability is better on the Supalite than anything lighter that I've seen.  The absolute lightest is the FMS-300t which is 45g/1.6 oz, but it has problems with clogging at the jet.  I can't recommend it (yet) even though it has some nice innovative design features.  I've read that the Optimus Crux has high CO, so you might avoid that if you want to cook in the vestibule.  I generally am not a fan of the MSR PocketRocket even though it's very popular.  I much prefer the newer MicroRocket.  The MicroRocket is a bit more compact than the Supalite.
The MicroRocket is particularly compact -- it will fit in a 550ml mug pot with a canister of gas.

Canister Stove Efficiency (Best Practices)
As for efficiency, with canister gas stoves, both upright and remote, it's typically more about how you use the stove than it is about the stove itself -- at least with the major stove brands.  All bets are off with "no name" stoves that one can buy off of eBay for shockingly low prices.  Caveat emptor.

However, with something like a Caldera Cone with a gas stove, that's another matter.  See the special section on the Caldera Cone at the end.

So, what are those good practices that lead to efficiency?  Well, here's my list:
  • Turn it down.  High heat = inefficient.  This is the number one mistake of canister stove users -- they turn things up too high.  Low heat = efficient.
  • Pick a sheltered spot.  On top of a rock might be convenient, but it's going to be windier up there.  Go behind the rock, and set the stove on the ground.
  • Use a windscreen (yes, even on an upright type canister stove, but not a full 360 degree windscreen) -- be careful to check the canister frequently with your hand.  If it feels hot, take immediate steps to cool things down.  See Canister Stoves and Wind before you use a windscreen.
  • Use a lid.  Tighter fitting is better.  Escaping steam = escaping heat = inefficient.
  • Use a wider pot.  Tall, skinny pots wind up having flames go up the sides, wasting heat.  A wide pot catches that heat.
  • Use a heat exchanger pot.  Usually the heat exchanger weighs more than the amount of fuel you save, but if you really want efficient, a heat exchanger is the way to go.  If on a trip you prevent having to carry a second canister, a heat exchanger can actually save weight overall.
  • Use a darker colored pot (minor compared to the others)

Windscreens -- Upright Canister Stoves
Yes, use a windscreen with an upright canister stove.  Just do NOT use a full 360 degree windscreen AND be really careful.  See Canister Stoves and Wind.

Windscreens -- Remote Canister Stoves
For remote canister stoves, you can use a full 360 degree windscreen safely.  Indeed this is one of the many reasons people use a remote canister stove even though it's heavier than an upright (the other main reasons are pot stability and improved cold weather performance).  With the Kovea Spider, I have just been using a plain heavy aluminum foil (~36 gauge) windscreen from MSR.  It's their standard windscreen for their remote canister and white gas stoves.  Works great.
A Kovea Spider stove with a standard MSR windscreen.
The Kovea Spider with a Caldera Cone
But can the Kovea Spider be used with a Caldera Cone?  Now that is an interesting question.  As a matter of fact it can.  Here's a Spider with a full height Caldera Cone and an MSR Titan Kettle.
A full height Caldera Cone with a Kovea Spider inside
The stove fits inside well.  The pot sticks up about 1cm or so -- not a problem.  In terms of efficiency, I think you could do very well with this set up.  You would want to be very careful to keep the flame low.   An aluminum cone could melt if you turned the heat up high.

Of course there are different styles of Caldera Cone.  Here's a Sidewinder style cone with a 1.3L Evernew pot.  This is a titanium Ti-Tri cone.
Sidewinder Ti-Tri (titanium) Cone with an Evernew 1.3L pot with a Kovea Spider inside
 A sidewinder cone is a shorter cone which is intended to be rolled and stored inside the pot (I really like the sidewinder design).  The pot therefore does stick out more.  Still, this would be a very effective windscreen, and the design of the vents, which control air flow and channel hot exhaust up the side of the pot, would increase efficiency.

You could of course take the pot supports off the Spider to save weight, but then you'd have to figure out a way to suspend the pot at the correct height above the burner.

Thanks for the questions; I hope the answers are satisfactory,