Recent Developments in Canister Stoves

[Roger Caffin]

Hi Jim

Yeah but …

I have serious reservations about hanging windscreens from the pot. I can't help thinking that the exhaust gases are going to be a bit choked, which may lead to more CO production.

Also, thinking about the typical piezo ignitor, I would have thought that if you can get your hand to the piezo button on the column of the stove, you could equally get a Bic lighter in there.

Of course, I may be missing a whole lot of things.

Cheers

[steven franchuk]

"The one that sits on the radiation shield is very similar to the one I remember being described on this site. You are right, the bowl one is also very good. They both are quite similar, in that they form a barrier between the heat source and the canister. I would think they would make things safer."

A radiation shield is potentially very dangerous. Radiation from the flames is normally not a big source of heat to the canister. Conduction however is. If you fully enclose the stove burner, the burner could get very very hot. That heat would then conduct down the stove to the valve body and then to the canister.

In at least one case the heat conducted down the stove body got the lindal valve hot enough that the valve actually melted:

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=65243

[James Marco]

Yes, windscreens should be very carefully used on toppers. Anything that will potentially hold or conduct heat to the canister can be bad with no control system in place to regulate that heat cunducted to heat sensitive components. The whole thing is a bit kludgy in my book. Toppers are, perhaps, one of the lightest stoves out there, but they are also prone to user modifications.

The external stoves, however, do not suffer from this. With any type of adequate air flow, only the fuel line would be vulnerable to heating/potential damage, even at relatively high heats (~200C or so.) This is far safer, it removes the fuel from the heating area. It is also heavier to build such a stove, as we know…

Anyway, things do not add up to me. Canisters of mixed fuels do NOT necessarily HAVE to have the super high pressure containment Roger so casually dismissed.
Propane is propane and has a gas pressure. Using pure propane is obviously dangerous in the light duty canisters used for camping fuels. Why doesn't the addition of 15-30% propane cause a dangerous situation just as 100% propane does? Acetylene has a very high gas pressure, yet we use it all the time as cutting/brazing torches at quite a bit lower pressure than has been indicated. This is because it is disolved in benzene or similar materials reducing the internal tank gas pressure. The same way that isobutane (or butane) reduces the internal gas pressure for our canisters…not that I am advocating acetylene as a prefered camping fuel, I am just saying there are facts we are missing when we talk about canister fuels, in general. The boiling point of the mix is also lowered. For example, freezing ethynol and water will drop the freezing point considerably below the freezing point of water, alone. 'Corse we are not interested in freezing points, but it also reduces the boiling point as any moonshiner will tell you. Adding ~25% propane to butane causes a reduction in overall canister pressure compared with 100% propane. The form a system at any temperature/pressure.

As far as HE pots effecting the flame pettern on the 300t, no doubt it will. This is relativly unimportant. What IS important is the mixing of sufficient air to cause complete combustion (low CO) and purging exhaust gasses(and heat) from the flame. Since a fairly high heat is required to produce CO, soaking the heat up into the "fins" would further reduce CO production. This would be facilitated by the HE pots, so I tend to think nothing would happen to the flame even if it did change shape, and, you would simply realize the better efficiency of the heat exchange.

[Ethan A.]

Roger, this is a great read – still have to finish it. Thank you for sharing your knowledge and recent research. I have Coleman Powermax Xtreme stoves for winter, but will run out of cartridges at some point (being way too busy at work this winter has preserved our stock for now). What is your current top pick for remote winter canister stove with preheat tube other than the Coleman Xtreme stove, and when do you think a new top contender might become available?

Wish some manufacture would revive the Coleman Xtreme style cartridges and fuel.

[Ethan A.]

Anyone reach out to Sievert of Sweden and any of the above-mentioned stove companies with user feedback for the ultimate lightweight and dependable winter stove? I'd imagine they'd be interested in our input.

[steven franchuk]

"Why doesn't the addition of 15-30% propane cause a dangerous situation just as 100% propane does? Acetylene has a very high gas pressure, yet we use it all the time as cutting/brazing torches at quite a bit lower pressure than has been indicated. This is because it is disolved in benzene or similar materials reducing the internal tank gas pressure. The same way that isobutane (or butane) reduces the internal gas pressure for our canisters…not that I am advocating acetylene as a preferred camping fuel, I am just saying there are facts we are missing when we talk about canister fuels, in general. The boiling point of the mix is also lowered. For example, freezing ethynol and water will drop the freezing point considerably below the freezing point of water, alone. 'Corse we are not interested in freezing points, but it also reduces the boiling point as any moonshiner will tell you. Adding ~25% propane to butane causes a reduction in overall canister pressure compared with 100% propane. The form a system at any temperature/pressure."

James you can get vapor pressures for various butane propane mixed from this site:

http://www.backpackinglight.com/cgi-bin/backpackinglight/mb_post_form.html?po=reply&note_id=639313&forum_thread_id=74642

At 40F the vapor pressure for:
100% butane 3.1psi
70% butane / 30% propane 21.5psi
50% butane / 50 propane 32.4psi
30% butane / 70% propane 46psi

According to the line there are no conditions where adding propane to butane cuases a pressure drop. Pressure always increases. At 110F the pressure in a canister of 100% propane will be 4 times higher than the pressure in a canister with 100% butane. The temperature in a car in the desert can easily exceed 130F in a hot desert location.

If you increase the pressure by adding propane you need to use thicker, stronger metal, and or change the shape of the canister to insure it doesn't rupture in your car.

"Acetylene has a very high gas pressure, yet we use it all the time as cutting/brazing torches at quite a bit lower pressure than has been indicated. "

For cutting or brazing you need the correct flame temperature, the correct air fuel mixture and enough fuel flow to do the job. Canister pressure only effects the flow. And the flow needed is typically very low. this means the pressure necessary to get the needed flow is typically but not always very low.

[Roger Caffin]

Hi EJ

> What is your current top pick for remote winter canister stove with preheat tube
> other than the Coleman Xtreme stove
Probably either the Kovea Spider or the Fire Maple FMS-118, if you stick with screw-thread canisters.

> and when do you think a new top contender might become available?
Soon, soon…

Cheers

[Roger Caffin]

> Anyone reach out to Sievert of Sweden
Yeah, but they weren't interested in this market.

Cheers

[James Marco]

Yeah, I think you might be reading that backwards.
I wrote:
"Adding ~25% propane to butane causes a reduction in overall canister pressure compared with 100% propane.

Yeah, never claimed to be a writer, poor syntax, I guess.

This is simply bourn out by the charts/numbers.

Adding small amounts of a solvent (benzene/acetylene in my poor example, all that I am really familiar with) can reduce the overall canister pressure significantly, of course it does reduce the overall flow rate, but, flow out of a canister is not a real problem except in winter. Propane would solve that, except for the pressure. Perhaps a small volume of other flamible gas will reduce that by providing a lower disolution pressure than current mixes of gasses.

[Bob Gross]

"> and when do you think a new top contender might become available?

Soon, soon…"

Waiting For Godot.

–B.G.–

[Randy Brissey]

Hello,

After reading about this little stove I searched for it and found it on eBay…….and bought one. The stove is incredibly small and light. Anyone wanting to get one…. a word of warning. Mine came to me in an "unprotected" condition. The seller (to save money on shipping from Hong Kong) took the stove out of the box and tossed the flattened box and contents into a bubble envelope.
The stove works properly but has suffered some damage from being at the "bottom of a pile".

Maybe I should have relied on a stateside dealer instead of eBay.

I am waiting for a reply from the dealer.

Randy B

[Stuart Murphy]

Hi Roger,

I "need" a new stove (a little sick of using the Pocket Rocket in the snow). Assuming I want to buy for the upcoming Australian season, should I go ahead and purchase a

Primus Omnilite TI?

Or is there something more compelling I should consider?

Realistically I would only use the stove with gas canister, but the flexibility of using other fuels appeals too. The Fire Maple 118t has reports of spluttering even when at stable operating temperature and I don't want to muck around with it to improve it.

Is there a lighter better option than the omnilite available do you think?

Cheers
Stuart

[Roger Caffin]

Hi Stuart

The Omnilite weighs a TON. And would you ever go back to petrol???? Dinosaur technology, with fireballs.

For now, either the FMS-118T or the Kovea Spider. (I have both.) The reports of sputtering were probably a feature of the user, not the stove. Learn how to strip the stove down and clean it at home. See our article on Stove Maintenance for more info.

Cheers

[Stuart Murphy]

FMS-118T vs the Kovea Spider

Thanks Roger,

I will investigate those two more thoroughly. Is your upcoming article likely to be of further assistance to me in this regard or should I go ahead and buy one of these?

Update: Just looked at the weights. The Omnilite Ti is only 220 or 240g (in gas canister mode) versus about 180 for the Spider. I gather gas stoves (even inverted canisters ones) are not that great below -10 deg C (not an issue in Australia), so maybe the multifuel option is worth the extra 40-60g (hard to know how often I'd need it… so far never).

What do people think of the 3 proposed alternatives?

Actually I'm deciding between the Spide and the Omnilite I think

Stuart

[Roger Caffin]

> Is your upcoming article likely to be of further assistance to me in this regard
Um.
I hope it might be.
Further than that I cannot say at this stage.

> or should I go ahead and buy one of these?
What's your timeline? If you need something in the next month or two, then I suggest buying one of these.

Cheers

[Stuart Murphy]

I want it for the start of the ski season…. so landed in Aus by June. To wait or not to wait… that is the question.

PS: Of those two stoves I've narrowed it down to the Kovea.

Cheers
Stuart

[Stuart Murphy]

I've ordered the Kovea since it takes up to 30-40 days to arrive (roll-eyes).

Thanks for your help Roger :)

Stuart

[Tyler Green]

I ordered my Kovea Spider from ebay seller alfresco_gear on 17 March fully expecting to wait a month or more for it to arrive from HK. Much to my surprise, it was sitting in my mail box today (25 March). The box was a little worse for the wear, but the stove was perfect. Fired it up and I'm very pleased. Also ordered the FMS-300T, but no sign of it yet.

[Stuart Murphy]

I ordered from ebay seller chovin.

Can't even find specific Australian shipping time info now, but have a vague recollection I read 30-60 days somewhere. That may have been for a random unrelated seller.

In any case, I'll plan for that and then there's definitely some room to be pleasantly surprised.

[Ken Larson]

If you are looking to purchase a Kovea Spider (KB-1109) Remote Canister Stove give Jinny a call at KOVEA and I believe she can facilitate you purchasing one within a week.

Jinny Min-
Price Zone dba
Kovea USA
213-747-0099
[email protected]

[Hikin’ Jim]

A 213 area code? Interesting. That's here in Los Angeles where I am. "Hmm," said Jim. :)

HJ
Adventures in Stoving

[Roger Caffin]

Hi all

I stated in the article that I thought that the Primus stoves were also made in Asia. However, the CEO of Primus has contacted us to let us know that:

'all Primus backpacking stoves except one is made in our own factory in Tartu, Estonia. This has been the case ever since production was moved there from Hagfors, Sweden in 1996.
Between 2004 and August 2009 Primus did supply Jetboil with burners. However, these products were made in our factory in Estonia and not in Asia as stated in the article.'

My mistake. The article has been corrected, and my apologies to Primus. Good to see that one of the Western companies is still making their own stoves.

Cheers
PS: I wonder whether I will get further corrections? Ah well, we'll see.

[Stephen Barber]

Ordered a Fire Maple 300t from [email protected] a day or two after this article came out. How can I resist a lighter stove???!!!

After warning me that I wouldn't see it until mid-April, it arrived this morning, in the original box, heavily wrapped in two different bubble wrap materials and a tough outer material.

The stove inside was in perfect shape.

Just sayin'.

[Hikin’ Jim]

Roger Caffin wrote: > I have serious reservations about hanging windscreens from the pot. I can't help thinking that the exhaust gases are going to be a bit choked, which may lead to more CO production.

It might, which is perhaps a good subject for testing, but would it matter? If I cook outside, the CO will dissipate. If I cook in the vestibule, then I won't need the windscreen, yes?

Roger Caffin wrote: > Also, thinking about the typical piezo ignitor, I would have thought that if you can get your hand to the piezo button on the column of the stove, you could equally get a Bic lighter in there.

Actually, it can be a lot easier to get to the button on a stove mounted piezo ignition. The button is typically mounted well below the burner head. With a lighter, I have to get above the burner head.

I'm not a big advocate of piezo ignitions, but they're definitely very convenient for suspended windscreens. If someone were wanting to use a suspended windscreen, I would think the Soto Microregulator would be a very strong contender. The Soto MR is a good stove despite all the silliness that it's going to somehow defy the laws of physics and work well when there's no pressure in the canister.

HJ
Adventures in Stoving

[Stuart Murphy]

… and it's a really nice little stove too

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