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,


Sunday, April 14, 2013

The Epicurean Ti ESBIT Stove

ESBIT is a common backpacking fuel.  ESBIT consists of hexamethylenetetramine, which is usually just called hexamine.  ESBIT is generally acknowledged to be the lightest weight method of cooking for backpackers.  In other words, if you want to lighten up, ESBIT might just be the fuel for you.
A typical 14g cube of ESBIT
But cooking with ESBIT is typically either all or nothing -- it's either burning or it's not -- unless you have an Epicurean Ti ESBIT stove.
An Epicurean Ti ESBIT stove from FlatCat Gear
Ultralight Baking with ESBIT
What can you do with low, steady heat from ESBIT?   How about ultralight baking?  Yes, I am serious.
A fresh blueberry muffin baked with an Epicurean Ti stove and ESBIT fuel
I was pretty blown away when I was told that I could bake.  I mean, come on, baking with ESBIT and an ultralight set up?  Now, that's cool!
A fresh-baked triple berry muffin.  Yum!
Today, I just want to cover the Epicurean Ti stove in detail, but if you're interested in ultralight baking with ESBIT, please see my article in Seattle Backpacker's Magazine:

I've been using the Epicurean Ti stove for about nine months now, and I'm super impressed with it.  First of all, it bakes and simmers.  Yes, an honest-to-God simmer using ESBIT.  That's no mean feat.  Simmering with ESBIT is just another example of the creative mind of Jon Fong over at FlatCat Gear.

Second, it eliminates (in simmer mode) all but the smallest amounts of the typical residue build up on the bottom of your pot.  My Ti pot is pretty beat up, so I don't know if you can see it well or not, but there's none of that sticky brown residue that ESBIT typically leaves behind.
The Epicurean Ti stove pretty much eliminates the brown residue of ESBIT when used in simmer mode
Third, when in simmer mode, the Epicurean Ti stove all but eliminates that nasty fishy odor that burning ESBIT produces.  I have however caught an occasional faint whiff when the wind gusts for a moment.  Still, it's like night and day the difference between using another stove and the Epicurean Ti in terms of smell.

The Epicurean Ti stove has two modes:  high and simmer.  Point the holes down for high, and...
An Epicurean Ti stove in high mode (holes down)
 ...point the holes up for simmering (and baking).
An Epicurean Ti stove in low mode (holes up)
In high mode, the ring portion of the stove focuses the heat, giving you better efficiency.  Note that on high you still do get the brown residue and odor.  Can't have everything I suppose.  In low mode, you can get 45 minutes or more burn time with a very controlled low heat.

So, now wait a minute.  Those little vent holes?  I mean come on.  How much of a difference can they really make?  Well, let's see.  Here's a photo with the holes down (high mode).  Note the height of the flame above the windscreen.
The Epicurean Ti stove operting in high mode
Now, here's a photo with the holes up (low mode).
The Epicurean Ti stove operating in low mode
As it turns out, the mode makes quite a bit of difference.

And what's the "weight penalty" for all this?  A mere fourteen grams -- the same weight as one cube of ESBIT.  Flat Cat Gear lists a weight of 19g for the Epicurean Ti stove, but I double checked just now, and my gram scale at home says 14g.  There may be some variation stove to stove.

Of course there are lighter ESBIT stoves, but very few ESBIT stoves have the kind of flame control that the Epicurean Ti stove has.  If however you did want a lighter weight option, there is the UL15 version of the Epicurean Ti stove which weighs only seven grams.  Note:  I have not used the UL15 version.

Wind Protection
Now of course ESBIT has to be used with a windscreen.  Trying to cook with ESBIT without a windscreen is often an exercise in futility.  You can use your own set up or purchase a very well tuned complete system from Flat Cat Gear, the Bobcat Stove System.  In my post on the Bobcat stove system, I show the Flat Cat stove, which is an alcohol stove.  For use with ESBIT, you would just swap out the alcohol stove and use the Epicurean Ti stove instead.  The Bobcat system works equally well with either stove.
The Bobcat stove system
Other Brands of Fuel
Of course there are other brands of hexamine fuel including Stansport and Coghlans.  The advantage of some of the other brands is that they are cheaper than the name brand, ESBIT.  But Stansport and Coghlans offer smaller, round fuel tablets, not the lozenge shaped tablets from ESBIT.
A box of round Coghlans brand hexamine fuel tablets
In my testing, I found that Coghlans brand works just as well as ESBIT; I just had to use two of the small Coghlans tablets instead of one ESBIT tablet.  The burn time is just slightly longer with two Coghlans tablets.  The Coghlans tablets are significantly cheaper in my area than ESBIT brand, so even though I have to use two tablets for every one ESBIT tablet, Coghlans is cheaper overall.  Coghlans does leave an odd ash behind.
The odd ash left behind by Coghlans brand hexamine fuel tablets
Tips for Use
Be sure to scrape the base plate of the stove clean between uses.  Mounding left behind by old fuel can cause the fuel to burn differently (typically hotter) which can leave you with a burnt supper.

Concluding Remarks
So there you have it, the Epicurean Ti ESBIT stove, an ESBIT stove that actually give you options in how you cook with ESBIT type fuel -- and opens up whole new possibilities in terms of things like ultralight baking.

The Epicurean Ti ESBIT stove from Flat Cat Gear.
What's good about it:
  • Flame control with ESBIT!
  • Can be used for ultralight baking
  • Residue on bottom of pot eliminated in simmer mode
  • Fishy smell eliminated in simmer mode
  • Light and effective
  • Easy to use
  • Can accommodate different brands of ESBIT type fuel
  • Compact, easily packable
What's bad about it:
  • At $27.50, maybe it's a little bit pricey, but it is of course titanium, and Ti is not cheap.  But there's no other ESBIT stove that I know of that offers this kind of flame control.
The Epicurean Ti ESBIT stove from Flat Cat Gear.:  Highly recommended.

Thanks for joining me on another Adventure in Stoving,


Thursday, April 11, 2013

A Little (Reactor) Levity from MSR

The MSR Reactor is of course a serious stove for those who travel into difficult conditions -- but that doesn't mean we can't have a little fun with it -- as shown in the humorous video from MSR, below.
An MSR Reactor
 Watch as supposed stove czar "Randy" compares the Jetboil to the Reactor.

Fortunately for that poor intern's sake, this video is mainly humorous and not real -- but there's some real content there. In winds that will blow out a Jetboil, the Reactor hardly even misses a beat.

On MSR's blog, there's a lot more factual information after the video. I'm not in a position to completely corroborate MSR's testing, but it certainly fits with what I've experienced with these two stoves.

What's my take on the Reactor vs. the Jetboil?  Here are my reviews of the stoves shown in the video:
The 1.0L MSR Reactor
The JetBoil Sol (aluminum version)

The Jetboil is lighter.  The Reactor is far and away more windproof.  Both are good water boilers.   Neither is a good stove for more than simple cooking.


Monday, April 8, 2013

Canister Stoves and Wind

I got a note from someone recently:
Hey Jim,
I'm really enjoying your adventures in stoving website.
I'm new to canisters, obviously, so I'm trying to play catch-up. I'm sure this is answered somewhere on BPL or on your website. But would you mind answering these 2 newbie questions?
1) Can the flame on a canister stove get blown out by the wind?
2) In your experience, is a windscreen valuable on an upright canister stove?
This is assuming the windscreen shields the canister from the heat source instead of reflecting the heat towards the canister. thanks for your advice and experience on this topic and others.
Yes, a canister stove absolutely can get blown out by the wind. Some Scouts were camped next to me when I was out doing some stove testing of the new 1.0L MSR Reactor. They took great interest in the Reactor when I explained to them that it was the most windproof upright canister stove, remarking "our Jetboils were blowing out on our last trip in the San Jacinto Wilderness."  And the Jetboil is actually more wind resistant than the typical upright canister stove.

Now, as to the second part of your questions, "is a windscreen valuable on a canister stove?" In a word, yes -- and for more reasons than just to keep your stove from actually blowing out.

First and foremost of course you want to prevent your stove from blowing out, but that's actually fairly rare.  Good site selection should prevent most full blow outs. 

Second, though, you want to prevent the wind from shifting your flame. You want that flame well centered under your pot. Take a look at this photo:
A flame shifted to the right by a very slight puff of wind
Notice how a light breeze has shifted the flame to the right. Where is the heat going? Well, it's not fully going into your pot. And what happens in a heavier wind?  Heavy winds can really play hob with your flame.  A windscreen can significantly reduce flame shifting.

Third, the windscreen helps trap heat. The flame heats the air that surrounds it. That hot air will help transfer heat to the pot, particularly if the windscreen channels the hot air up along the sides of the pot. Remove that windscreen, and the hot air gets dispersed by normal air circulation or wind.  Notice how in the photo below that the hot air around the flame is completely free to disperse into the surroundings. 
A very exposed, unprotected flame.   Note how the sides are completely open.
Lastly, the one time you really do have to worry about your flame getting blown out is on very low flame settings.  Using a windscreen allows you to use a low flame without having your stove blow out altogether, thus giving you greater control over your cooking. 

Why a windscreen?
You want to use a windscreen to
  • Prevent your stove from blowing out
  • To keep the flame centered (i.e. prevent flame shifting)
  • To trap the heat near the pot.
All of the above contribute to greater efficiency, faster speed, greater control, and, in higher winds, the ability to cook at all.

What kind of windscreen?
Ah, that's all very well and fine, Jim, but what kind of windscreen should I use?  Well, first, do NOT use a full 360 degree windscreen on an upright canister stove. An upright canister stove is a canister stove that screws directly into the canister (sometimes also called a "top mounted" canister stove).  If you fully surround the stove, you could trap so much heat that you overheat the canister and cause an explosion, which could have severe if not deadly results.

Here's a windscreen that I've found useful:
A windscreen made of quadrupled heavy aluminum foil.  Note the partial opening to prevent overheating.
Note that in the photo above that there is snow to the left of my stove.  It was January when I took this photo and I'm atop an 8,000+ foot/2400+ meter peak.  The gap I left in the windscreen is fairly small, which is fine for such a day.  ALWAYS, ALWAYS, ALWAYS monitor the temperature of your canister with your hand when using a windscreen with an upright canister stove.  If the canister feels hot, take immediate action to prevent overheating.  Open up the windscreen, turn down the stove, or even stop cooking if need be.  DO NOT allow the canister to overheat.  That would be, um, bad.  Bad as in a potential stay in the the hospital -- or worse.  Note that every manufacturer says not to use a windscreen in any form for this very reason.  I think a windscreen is reasonably safe if you consistently and frequently monitor the canister temperature with your hand, but keep in mind that you are going against the manufacturer's recommendations.  Nothing prevents a serious accident but you and your good sense.  The benefit though is of course significantly lower fuel use, faster cooking, and in some cases the ability to cook at all.  In significant winds, an upright canister stove may not be able to bring water to a boil at all, no matter how hard your try, without a windscreen.  The lawyer who wrote the warning on your stove probably didn't have to worry about that.  You do.  Windscreens are reasonably safe if you are diligent but potentially deadly if you are not.  Fair warning.

An aluminum foil windscreen made from multiple sheets of foil.  
The windscreen in the above photo is made out of heavy household aluminum foil of the type you can get at any grocery store.  I use three or four sheets folded at the edges to hold them together.  Note that it's light and needs to be braced with rocks in heavier winds.  It's not super durable, but will hold up for multiple weeks worth of hiking with reasonable care.  I fold mine in half lengthwise, roll it around a water bottle, and put the resulting bundle into a bagel bag for protection before putting it in my pack.
My windscreen rolled and wrapped, ready for packing.
Crafter's foil, also called tooling foil, of about 36 or 38 gauge is more durable.  I've found crafter's foil available on eBay.  Titanium foil is better still, albeit pricier.  Some have used aluminum roofing flashing to good effect although flashing is a bit heavier.

Note that you need a screen of sufficient height to accommodate the sizes of canisters you will use.  A 110g canister is far shorter than a 220g canister which is in turn far shorter than a 450g canister.  A windscreen for an upright canister stove on a 450g canister is so tall that it's frankly a royal pain in the posterior.  I'm not sure I can really recommend the above shown type of windscreen with a 450g canister.

Naturally, there are a lot of other ideas beyond the simple windscreen I'm showing here.  I address some of those ideas in a another blog post:  More Windscreen Ideas

Al foil as a windscreen
  • Cheap
  • Easy to get
  • Easy to work with
  • Light

  • Needs to be braced with rocks in moderate to high winds
  • Not all that durable (but not all that bad either with reasonable care)

It's cheap, easy, and available, so experiment away. If you find it's not working for you in terms of durability or stability, then by all means seek out tooling foil, flashing, or titanium foil.

I hope you find this helpful,


Thursday, April 4, 2013

Blog Status, 4 April 2013

Things are going reasonably well here at Adventures in Stoving.  We just passed half a million site views in early March, about 2 years after starting.  Readership was over 40,000 site views last month which is the highest it's been since I had to put the blog essentially on hold April 2012 - January 2013 while I worked a job that required me to commute 100 miles a day.  I'm now working closer to home, and I'm able to get back to blogging.

Speaking of work, I work for a bank that's going through a merger.  We're working 7 days per week to get the job done by the end of April, which doesn't leave me a lot of time to get out on the trail.  Things may be just a little sparse between now and the end of April, but I've got some good stuff that I've prepared ahead of time, so stay tuned.

The Adventures In Stoving team, out on the trail.
 On other fronts, I wanted to make you aware of an interesting KickStarter project called Hot Fingers.  Hot Fingers is the brain child of budding industrial designer Mike Oldani.  I'll let Mike speak for himself:

I haven't tried the product myself, but I like to encourage innovation.  If you're of a mind to, why don't you kick in a buck or two for the project?

My thanks as always to you, my readers.