Forum Index » Editor's Roundtable » Thermal Feedback in Upright Canister Stoves


Display Avatars Sort By:
Maia
(maia) - MLife

Locale: Rocky Mountains
Thermal Feedback in Upright Canister Stoves on 03/05/2013 16:16:58 MST Print View

Companion forum thread to:

Thermal Feedback in Upright Canister Stoves

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Thermal Feedback in Upright Canister Stoves on 03/05/2013 18:00:28 MST Print View

Another good article, Roger, I'll have to digest it a bit more...

I detect a new Caffin product coming.

You have a CNC machine? Nice.

Maybe there could be an upright canister stove with more thermal conduction back to canister? There's an O-ring and the pin pushing the Lindal valve which don't make very good thermal conductivity. Maybe some way to improve on that. Wouldn't want to use it in warm weather which might make it an unviable product from legal perspective.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Thermal Feedback in Upright Canister Stoves on 03/05/2013 19:14:18 MST Print View

> I detect a new Caffin product coming.
Who, me ???

> Wouldn't want to use it in warm weather which might make it an unviable product
> from legal perspective.
Have to disagree. You can do a lot by adjusting the windscreen on an upright, and many people already use remote canister stoves in summer. There are even remote canister stoves which do NOT handle inverted canisters.

More to the point, I would argue that you should never operate a stove of any sort without good supervision. Summer, winter, does not matter. make sure the stove is running normally and the fuel container is touchable.


I was chatting some years ago with someone who had two stoves running full bore, side by side, with large pots. No real supervision. Eventually cross-radiation took at least one fuel tank beyond critical, and it blew. They lost their tents, which was minor. Two people recieved extensive third degree burns from the BLEVE over a lot of their bodies. Fortunately they were able to get an airlift to Emergency, so they lived, but the scarring was extensive.

Be careful and be safe.

Cheers

Stuart R
(Scunnered) - F

Locale: Scotland
Re: Thermal Feedback in Upright Canister Stoves on 03/06/2013 03:20:19 MST Print View

Nice article Roger, which pretty much matches my own experience. Here's an early stove I made which suffered from too much heat conduction down the aluminium mixer tube, which damaged the o-rings in the valve. This was based on a Coleman F1, so this might be a good candidate for an upright stove, were it not for the plasic bits.

F1 remote canister stove

My view is direct heat conduction from the burner is too difficult to get right: too much conduction and the whole stove gets too hot, too little means a longer warmup time before you can switch to liquid fuel. My current stove has a titanuim burner and mixer tube to minimise conduction by that route and a conventional vapouriser tube for fast startup.

I agree that valving gas (as opposed to liquid) gives better flame control, but there are practical drawbacks to this arrangement when the stove is surrounded by a windscreen, plus the potential for heat damage to o-rings. Also, I once had a pot of almost boiling water tip off a stove when I was adjusting the valve - now I prefer to keep my hands well away! The difficulty of valving liquid can mostly be overcome by having a very fine thread and a shallow taper on the needle and a low volume tube betweent the valve and the stove. No need to make, if you know where to look.

Kevin Babione
(KBabione) - MLife

Locale: Pennsylvania
Thermal Feedback on 03/06/2013 07:46:53 MST Print View

I'm a stove user, not a designer, but could you make some sort of a hybrid approach to preheat the feed tube? I'm thinking of a small cup that would hold 10-15 ml of alcohol that you would light in very cold temperatures to preheat the tube and then, after a couple of minutes, start the flow of your primary fuel?

It seems to me that this would eliminate the stove startup issues by heating the fuel tube until the stove was generating enough of it's own heat to take over (by which time the alcohol would have burned off).

Daniel Fish
(daniel@fishfamilypdx.com)

Locale: PDX
... on 03/06/2013 09:31:56 MST Print View

...

Edited by daniel@fishfamilypdx.com on 06/12/2013 08:17:57 MDT.

David Thomas
(DavidinKenai) - MLife

Locale: North Woods. Far North.
Re: Thermal Feedback on 03/06/2013 09:57:21 MST Print View

>"I'm a stove user, not a designer, but could you make some sort of a hybrid approach to preheat the feed tube? I'm thinking of a small cup that would hold 10-15 ml of alcohol that you would light in very cold temperatures to preheat the tube and then, after a couple of minutes, start the flow of your primary fuel?"

Actually, Kevin, you apparently are a stove designer. I think you just designed a SVEA 123.

Here's our own HikinJim priming one with denatured alcohol:

http://www.youtube.com/watch?v=TfRRs4x51k8

But the alcohol used is more like 3 ml on a cool day. Maybe two such treatments ( 2 x 3 ml) in snow-camping conditions.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: low temp limit of remote liquid feed stove on 03/06/2013 10:03:17 MST Print View

Since no one answered your question:

When I put an iso/propane canister in the freezer, which must be 0 F or maybe -10 F, no gas came out. If it was inverted, no liquid would come out. The minimum temperature you can operate an inverted stove must be warmer than that temperature.

At 25 F I've operated upright canister, but very slow at that temperature. 30 F is good but a little slow.

So, maybe inverted stove is good between 0 or 10 F and 25 or 30 F.

Oh, if you take 1 foot of solid copper maybe #14 gauge, wrap it around canister and up into flame, it will warm up canister enough so it is usable in that range, and maybe even below if you pre-warm it in your pocket.

Daniel Fish
(daniel@fishfamilypdx.com)

Locale: PDX
... on 03/06/2013 10:35:27 MST Print View

...

Edited by daniel@fishfamilypdx.com on 06/12/2013 08:21:40 MDT.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Thanks Jerry! on 03/06/2013 10:46:20 MST Print View

Don't assume it will work at 0 F. It might work there.

I think you can assume it will work at 10 F, but that's just a guess.

Inverted stove should work at 20 F, because I've sort of got upright to work there.

Maybe someone with more than an opinion will respond

Edited by retiredjerry on 03/06/2013 10:47:10 MST.

David Thomas
(DavidinKenai) - MLife

Locale: North Woods. Far North.
The Chemical Engineer gets pedantic. And no one is surprised. on 03/06/2013 10:53:35 MST Print View

I like the article and the helpful overview it gives. I did however tweak on the sentence, "The higher the boiling point, the more energy is needed to vaporise the fuel." and not just because someone replaced the "z" in vaporize with an "s".

I'd accept that "The higher the boiling point, the more TEMPERATURE is needed to vaporise the fuel."

But when I look at Hvap for different fuels, as the boiling point goes up, the heat of vaporization (in kJ/kg) goes down. When I factor in the slightly decreasing heat of combustion for higher MW fuels, the normalized Hvap still goes down. When I include all the conversion factors, I think I end up with a new dimensionless number (stand back Mr. Reynolds and Mr. Prandtl!) the meaning of which is:

The fraction of a liquid fuel needed (to be burned) to vaporize itself:

propane 0.0102
butane 0.0094
hexane 0.0091
decane 0.0068

Yes, they are all close to 1% which is shoot-from-hip, ballpark, reasonable. But higher MW fuels need a smaller fraction of their available BTUs to vaporize.

You may reference this as the "Thomas Number". But if you convert to Australian by turning it upside down and firing the stove on Foster's beer, then it is the "Caffin Number".

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Thermal Feedback in Upright Canister Stoves on 03/06/2013 11:32:06 MST Print View

Roger,good article. Looking forward to part II.
Yeah, the problem is balancing the thermal feedback to safe levels with canisters and "toppers." It is generally easier to insure that your fuel is hot or hotter than needed and avoid heating the canister at all. This simply devolves to the simplistic aproach you took with remote canisters. This also allows the use of cone type wind screens...you really don't care of the valve and burner get hot, just the fuel line needs to stay cool.

Good job!

Eric Petritz
(ericpetritz) - MLife

Locale: Montana
Thermal Feedback in Upright Canister Stoves on 03/06/2013 12:10:15 MST Print View

Nice article Roger. I am an engineer too and I always enjoy reading your articles about stoves. Well done and I look forward to reading more of your articles in the future!

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: low temp limit of remote liquid feed stove on 03/06/2013 12:46:39 MST Print View

> I'm curious about the theoretical lowest operating temperature of a remote canister liquid feed stove ( aka the msr windpro ii ) .

Theoretical lower limit would be about -40C as long as you had some propane remaining. You'd need to do some fudging to warm the canister a bit to keep it going well.

You may find this article interesting.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: low temp limit of remote liquid feed stove on 03/06/2013 14:34:28 MST Print View

> theoretical lowest operating temperature of a remote canister liquid feed stove
This depends very much on what fuel is in the canister. Read our article Temperature Effects on gas canisters to get a good understanding. To be sure, you can get fuel out of most blended canisters down to -20 C or further, and the higher you go in altitude the lower you can go in temperature - which is convenient. Pure isopropane works below -10 C as well.

But this ignores some convenient practical points: the interior of my pack is never that cold (because my back keeps it warm), and a little liquid water will warm a canister up nicely. I have poured water over a canister in the cold and heard the gas inside boil! And I have stored the canister under my quilt overnight in the snow.

So in practical terms you can use a canister stove at significantly lower temperatures than -20 C if you are smart.

Cheers

Edited by rcaffin on 03/06/2013 14:54:39 MST.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: The Chemical Engineer gets pedantic. And no one is surprised. on 03/06/2013 14:42:53 MST Print View

Hi David

> "The higher the boiling point, the more energy is needed to vaporise the fuel."
Fair question. I was including the requirement to heat the fuel up from, say, 20 C to wherever it boils. Obviously, it takes a lot more energy to heat diesel to 300 C than hexane to 69 C. But no, I did not do the calculations to justify that.

S and Z - flavour to taste.

Cheers
PS: your contributions are appreciated.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Thermal Feedback in Upright Canister Stoves on 03/06/2013 14:52:51 MST Print View

Hi Stuart

> suffered from too much heat conduction down the aluminium mixer tube,
Yeah, problems there. Make the walls of the tube thinner? Air holes elliptical?

The problem with vaporiser tubes is sealing them. That's why the base block on the FMS-118 is heavy brass rather than Ti or Al. We await a good solution to that one. Not easy.

> there are practical drawbacks to this arrangement when the stove is surrounded
> by a windscreen
I really do agree, but I don't have that problem as I never completely surround my stove. I always have a decent gap downwind with the valve handle sticking out there. In addition to giving access to the valve it ensure plenty of oxygen. That has always worked for me.

I will add that having a secure stable base for the stove is important, and often ignored. I always spend a little time preparing the place where I put the stove base so that it is stable. More on that in a future article.

Cheers

Stuart R
(Scunnered) - F

Locale: Scotland
Re: Re: Re: Thermal Feedback in Upright Canister Stoves on 03/06/2013 15:21:11 MST Print View

Hi Roger

> The problem with vaporiser tubes is sealing them.

At the stove end I drilled a hole thru' the centre of a brass M5 bolt and then brazed the SS vaporiser tube into the hole. The bolt with tube then screws into the aluminium base, with a little anaerobic threadlock for good measure.
The fuel line is attached to the other end of the vaporiser tube with a crimped on brass ferrule.
No leaks so far.

Jim Sweeney
(swimjay) - MLife

Locale: Northern California
thermocouple? on 03/06/2013 15:52:45 MST Print View

If we work backwards, it seems that the ideal is to maintain a short stretch of fuel line, occurring before the control valve, at a given temperature, the temperature required to vaporize the fuel traveling through the line. Once the stove is going, the heat available to do this is the cooking flame, and Roger has tried various conductive paths-- extra metal of various types, the metal of the stove itself--to achieve this. What about a more active conductive path, one that was self-regulating?

Just as a thought experiment, imagine that we could use the heat of the stove to generate electricity, then use that electricity to heat the tube, with an intervening active thermostat-like circuit that would maintain the tubing temp at the correct point-- we'd be done. Environmental factors, wind screens, would all be taken care of.

Not practical yet. But perhaps there's some kind of thermocouple-like solution possible, one that would open or close a heat path as needed?

Just sayin'.

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: thermocouple? on 03/06/2013 15:55:04 MST Print View

I can envision a whole new job field for thermocouple repair technicians.

--B.G.--

David Thomas
(DavidinKenai) - MLife

Locale: North Woods. Far North.
Re: Re: The Chemical Engineer gets pedantic. And no one is surprised. on 03/06/2013 15:55:44 MST Print View

>:"Fair question. I was including the requirement to heat the fuel up from, say, 20 C to wherever it boils."

Got it. While for fuels gaseous at ambient temps (propane, often butane), you primarily need to provide the latent heat, for high-boiling compounds, you need to provide a lot of sensible heat as well. Yes, then diesel would need to absorb more heat to boil than white gas than butane. Also, because the deltaT is less between the burner flame and heavier fuel to be heated and because the heated fuel vapor will have more losses once it leaves the vaporizer section, you'd need an even larger convective or conductive heat exchanger to heat that fuel.

Stephen Parks
(sdparks) - M

Locale: Southwest
Thermal feedback regulation on 03/06/2013 19:51:04 MST Print View

Hello all, this is my first post at BPL!

I had some thoughts on regulating the thermal feedback to the inlet tube based on temperature. Don't discard your heat shunt concept just yet.

You might be able to achieve regulation (preferably automatic regulation) by either varying the thermal conductivity of some parts of the stove, or by varying the exposure to thermal energy of some parts.

To vary the thermal conductivity of the structure, it would be nice to have a material that has a thermal conductivity with a strong and inverse dependence on temperature. As the temperature of the conducting parts rose, the conductivity would decrease, thereby reducing the thermal energy transmitted to the fuel. Unfortunately, I don't know of any such materials.

But, varying the exposure of the inlet tube and connected parts may be possible. In this case, you would want something to move as the temperature rose. What I imagine here is one of your flat metal shunts made out of bi-metal sheet. As the temperature of the shunt rose, the shunt would bend away from the flame, reducing its exposure and consequently the amount of heat conducted down to the inlet tube. The regulation would vary smoothly with temperature. Alternatively, you might find a shape memory alloy that would bend out of the way at an appropriate temperature. This deflection could potentially be much greater than with the bimetal, but all the deflection would occur over a narrow temperature range, which might be ok or even desirable. Or, you could go low-tech and just put your shunt on a hinge and manually flip it out of the way or adjust it once the stove is warmed up, at least for initial testing. You would probably want the rest of the stove to be designed to contribute relatively little heat transfer to the inlet tube, so that the moving component could have maximum control of thermal feedback.

You might think of other variations on this theme.

-Stephen

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Re: Thermal Feedback in Upright Canister Stoves on 03/06/2013 20:30:25 MST Print View

Hi Stuart

> a hole thru' the centre of a brass M5 bolt and then brazed the SS vaporiser tube
> into the hole. The bolt with tube then screws into the aluminium base
Yes, I played around with this idea too, but I had trouble getting it miniaturised and hermetic. It remains possible though.

> a little anaerobic threadlock for good measure.
That bit worried me. Most anaerobic threadlocks are based on methacrylate, which has a limited tenperature range. Maybe a silicone sealant could be used instead?

Maybe I will have another look some time.

Cheers

Jim Sweeney
(swimjay) - MLife

Locale: Northern California
thermocouple shunt on 03/06/2013 20:33:10 MST Print View

Stephen, that's something along the lines of what I was proposing. Great minds think alike.

Unfortunately, so do mediocre ones.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Thermal feedback regulation on 03/06/2013 20:33:14 MST Print View

> flat metal shunts made out of bi-metal sheet.
Novel! I imagine it could work.
But sourcing the material ...

Cheers

Jim Sweeney
(swimjay) - MLife

Locale: Northern California
bi metal coils on 03/06/2013 20:51:30 MST Print View

not sure if they could be made to work in this application, but bi-metal coils are at the heart of most house thermostats, and there's probably a mature technological base that knows how to manipulate their properties.

T N
(tordnado) - MLife

Locale: Europe
Bi-metal, now were talking! on 03/07/2013 00:44:28 MST Print View

Bi-metal sounds very interesting and it should not be hard or expansive to source.

Picture: http://www.google.se/imgres?imgurl=http://www.hilli1.de/Physik/Folien/Waerme1/Bimetall.gif&imgrefurl=http://www.hilli1.de/Physik/Folien/Waerme1/Bimetall.htm&h=660&w=514&sz=23&tbnid=oZjbVetxRYXVOM:&tbnh=89&tbnw=69&zoom=1&usg=__IAb2lOT2K7tr0ORmGJq8mXWP4rc=&docid=1VfhP_GJPe_5DM&hl=sv&sa=X&ei=FkY4Uf6QO4vesgbykYCYBA&ved=0CEAQ9QEwBQ&dur=670

Edited by tordnado on 03/07/2013 00:49:57 MST.

David Thomas
(DavidinKenai) - MLife

Locale: North Woods. Far North.
Or just metal rods. on 03/07/2013 01:45:14 MST Print View

It doesn't even have to be bimtallic in the traditional sense of two alloys continuously bonded to each other. Simply two metal rods triangulated with a narrow base would, if allowed to pivot, bend away from the hot side. The hot rod could be either a conductor of heat to a vaporizer or the vaporizer tube itself. The cold rod could be a turnbuckle to field tune it for ambient temps or different fuel types ( butane, white gas, diesel, yak's milk, etc).

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Or just metal rods. on 03/07/2013 11:58:07 MST Print View

So, what is the heat of vaporization of yak's milk?

--B.G.--

Stephen Parks
(sdparks) - M

Locale: Southwest
Re: Re: Thermal feedback regulation on 03/08/2013 20:04:04 MST Print View

>Novel! I imagine it could work.
>But sourcing the material ...

I don't usually give novel ideas away. If you make it big in the stove industry, you owe me some CNC play time...

Here's some useful info on bimetals. These guys would probably send you some samples if you tell them you are developing a product.

http://www.cladit.com/tech.html

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Thermal feedback regulation on 03/08/2013 20:50:00 MST Print View

> http://www.cladit.com/tech.html

f a s c i n a t i n g...

Cheers

Hikin' Jim
(hikin_jim)

Locale: Los Angeles, CA, USA
Re: Thermal feedback regulation on 03/08/2013 22:52:56 MST Print View

Roger,

Very interesting what you've learned by experimentation (and frustration at times, no doubt). Sounds like it's all about the heat and consequent pressure within the canister although I still wonder some about the Jetboil Sol (although I suppose if I'm really curious I can do a bit of experimentation).

Interesting bit about the difficulty of sealing a pre-heat loop. The FMS-118 Volcano at least has the sealing right (although it seems they've got the diameter a bit too big).

I do notice the Kovea Moonwalker uses a shunt instead of a pre-heat loop. The one thing I don't like about this arrangement is that the whole stove gets quite hot and takes a while before I can reasonably pack it away, but the Moonwalker has a lot of metal. Smaller, UL style stoves will likely not have this problem.

It's late, and I don't have any particularly brilliant insight to add (would that I did), but I thank you for writing yet another article that very few people are in a position to write. It is such articles that make BPL such a great place to be a part of (well, and the people too of course).

HJ
Adventures In Stoving

Hikin' Jim
(hikin_jim)

Locale: Los Angeles, CA, USA
Re: Re: Thermal Feedback on 03/08/2013 22:59:35 MST Print View

Actually, Kevin, you apparently are a stove designer. I think you just designed a SVEA 123.

Here's our own HikinJim priming one with denatured alcohol:

http://www.youtube.com/watch?v=TfRRs4x51k8

But the alcohol used is more like 3 ml on a cool day. Maybe two such treatments ( 2 x 3 ml) in snow-camping conditions.

E-gads! Is that old thing still out there? That was B.T. (before tripod). I hope you take motion sickness meds before viewing.

The idea of priming a remote canister stove with alcohol has merit, particularly one that is designed for it. For example, the WindPro is really a white gas stove (the Simmerlite) that has been repurposed for use with canister gas (and it outlived its parent, the Simmerlite, which alas has been discontinued). The WindPro's head will hold alcohol and it has a small priming cup. Very interesting. Suppose one filled the head with alcohol and ignited it. The edge of a cold canister could be held into the flame. The flame would a) heat the canister and b) heat the pre-heat loop. One would then open the valve, and voila! no-flare inverted start ups with plenty of pressure. Conceivably, one could operate in very low temperatures this way. Adding a bit of fiberglass wick, as on a Whisperlite Internationale, would increase the vaporization of the alcohol which could be quite balky in cold weather. Hmm. Interesting.

HJ
Adventures In Stoving

Hikin' Jim
(hikin_jim)

Locale: Los Angeles, CA, USA
PowerMax or 7/16ths UNEF or Camping Gaz on 03/09/2013 00:25:55 MST Print View

Roger,

I just noticed this elsewhere on BPL regarding your MYOG canister remote stove:

Works with standard screw-thread canisters, French Campingaz canisters, and Coleman Powermax canisters, all in full winter mode. This means I can use it virtually anywhere around the world.
I noticed the PowerMax canister in the photo here in your article (of which I have laid in a goodly supply), but your stove also works with standard threaded and Camping Gaz? Now, that's nice.

How did you do it? Do you have a connector that fits over the rim around the valve, something along the lines of how an MSR SuperFly connector works? Is the pin any different between a PowerMax, Camping Gaz, or standard threaded stove?

HJ
Adventures In Stoving

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: PowerMax or 7/16ths UNEF or Camping Gaz on 03/09/2013 02:01:00 MST Print View

Hi Jim

All the details, in great and gory (or glorious) depth, will be revealed soon. The connector is more like the French Campingaz one than the Superfly. I tried the Superfly and was, frankly, a bit scared of the way MSR had done it. Things flexed ... It was not an option for me.

The pin - you would not believe how much trouble that gave me! The Lindal valves are all different. Yes, a solution was found, and yes, it will be in the article to come.

Fwiiw: I have been using my winter stove for 6 - 9 months now.

Cheers
(Yes, I know I'm mean not giving all the details now ...)

Rex Sanders
(Rex) - M

Locale: Central California Coast
Why not 100% propane in canisters? on 03/09/2013 10:51:55 MST Print View

IANASG (I am not a stove geek), so maybe this is a dumb question:

Given all the troubles vaporizing butane, why not make light canisters with 100% propane specifically for winter use?

Why are Coleman-style propane steel canisters the only ones on the market anywhere close to backpacking size?

(Edit) And to answer my own question:

http://www.backpackinglight.com/cgi-bin/backpackinglight/canister_stove_faq

Edited by Rex on 03/09/2013 10:56:30 MST.

David Thomas
(DavidinKenai) - MLife

Locale: North Woods. Far North.
A pound of propane takes a pound of steel. on 03/09/2013 12:12:40 MST Print View

As the link you added explains, pure propane is so high pressure, it requires thicker steel. About exactly the weight of the propane regardless of size (14 oz. 16 oz, 20-pound/4.5-gallon, 80-pound, etc).

There are about three people on this very gear-heady site that I'd trust to load their own lighter canisters for winter-only use and be damn sure they never got above room temperature during transit and use. Those safety margins are used for good reason as HikinJim, RogerC, and I have all proved at times.

Now if someone offered a refillable 200-gram fuel weight aluminum or titanium propane canister, I'd order a handful.

Kevin Schneringer
(Slammer) - MLife

Locale: Oklahoma Flat Lands
Natural Gas? Efficient and clean on 03/09/2013 13:01:19 MST Print View

I own a Chevy Siverado that I had converted to Run on Natural Gas. It has a polymer tank that is wrapped in fiberglass and carbon fiber.
It has a fill pressure of 3600 PSI.

I just use public fill stations but there are several types of home filling stations.

It would be nice to just have a small refillable bottle to use with my stove! No more issue with low temps and no more canisters in landfills.

Maybe 3M or GE see an ultralight mini tank in there future?

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Natural Gas? Efficient and clean on 03/09/2013 14:06:19 MST Print View

> It has a polymer tank that is wrapped in fiberglass and carbon fiber.
Bring it on!!!!!

But the cost of production would likely be swamped by the cost of development and insurance and safety testing and getting approvals and ...
Sigh.

Cheers

Kevin Schneringer
(Slammer) - MLife

Locale: Oklahoma Flat Lands
Yep on 03/09/2013 14:18:27 MST Print View

Roger that is most definitely the problem!
It is amazing what is out there just waiting
Well my son can look forward to such high tech gear!
In 25 years who knows what possible

Hikin' Jim
(hikin_jim)

Locale: Los Angeles, CA, USA
Re: Re: PowerMax or 7/16ths UNEF or Camping Gaz on 03/09/2013 22:28:37 MST Print View

The connector is more like the French Campingaz one than the Superfly.
Ah. Interesting. And it works with threaded too. Fascinating.

The pin - you would not believe how much trouble that gave me! The Lindal valves are all different. Yes, a solution was found, and yes, it will be in the article to come.
Actually, having tried my hand at canister refilling, I very much would believe it.

I will look forward to the article,

HJ
Adventures in Stoving

Hikin' Jim
(hikin_jim)

Locale: Los Angeles, CA, USA
Re: Why not 100% propane in canisters? on 03/09/2013 22:38:28 MST Print View

Given all the troubles vaporizing butane, why not make light canisters with 100% propane specifically for winter use?
Propane's a frisky critter, and it's tough to keep him caged.

Even so, there was a light weight canister out there, but it was for torches, it was a specialty item, and it didn't stay on shelves long. It may have had approval problems or maybe there just wasn't demand for it; I really don't know. I have two such canisters in my collection.


More info on said canisters: 100% Propane for Backpacking

HJ
Adventures in Stoving

Hikin' Jim
(hikin_jim)

Locale: Los Angeles, CA, USA
Refillable 226g Propane Canisters on 03/09/2013 23:02:59 MST Print View

Now if someone offered a refillable 200-gram fuel weight aluminum or titanium propane canister, I'd order a handful.

Well, the one pictured above is 226g, and while not officially rated for refills, yes you can refill them with 100% propane. Problem is they're hard to find. Supposedly there were still some available in Boise, ID, last I heard.

HJ
Adventures in Stoving

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Why not 100% propane in canisters? on 03/10/2013 03:18:53 MDT Print View

Hi Jim

> there was a light weight canister out there, but it was for torches, it was a specialty item,
Sigh. Never in Oz. SIGH!

Cheers

Franco Darioli
(Franco) - M

Locale: Melbourne
Thermal Feedback in Upright Canister Stoves on 03/10/2013 04:04:20 MDT Print View

Sigh. Never in Oz. SIGH!
Actually Bunnings (Melbourne) had them but for a very short time.
By the time I realised their potential they had disappeared from the shelves...

Stuart R
(Scunnered) - F

Locale: Scotland
100% propane in aluminuim canisters? on 03/10/2013 07:22:08 MDT Print View

Does exist, altho I have yet to see one in a shop
Sievert propane canister

Jeffs Eleven
(WoodenWizard) - F

Locale: Greater Mt Tabor
Re: 100% propane in aluminuim canisters? on 03/10/2013 10:31:31 MDT Print View

It even says "Manufactured by Primus" on that link.

Why cant they get it going? They're already set up with the proper segment of retail/ distribution.


must be a safety issue. only welders and people who are 'trained' with compressed gases?


--ironically I was typing "distribution" and accidentally typed "disastrbution" (disaster) maybe that was The Big Bang telling me why they DON'T make em. lol

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: 100% propane in aluminuim canisters? on 03/10/2013 15:59:10 MDT Print View

> Why cant they get it going? They're already set up with the proper segment of
> retail/ distribution.

To import these into a country I believe they have to get safety approval in that country, and they have to use approved shipping methods. They can't use air-freight, so it has to go by sea. That normally means waiting for a cargo to be ready, unless they make up a special sea-mail parcel. This is only worth doing if they think the sales volume will be big enough.

I have argued the point at some length with both the Sievert people in Europe and the Primus people in Australia, and it seems they are just not interested in bothering to do the paper work. If only I could get some of the empties, before they were filled! Certify them as clean (no fuel) and airfreight.

SIGH. IF ONLY!

Cheers

steven franchuk
(Surf) - M
Re: 100% propane in aluminuim canisters? on 03/10/2013 18:47:35 MDT Print View

The aluminum in that can is probably a lot thicker than aluminum used in the old Power Max butane canisters. The empty can probably weighs significantly more and it may not be easy to crush.

The problem getting a new fuel can in the market dominated by 7/16" NCEF threaded lindal valve canisters is getting enough market to justify the product. And people might not buy the product because it would require a different stove or because the stove would be rendered useless if the canister is removed from the market.

However if a company brought a aluminum canister to the market with a 7/16" threaded lindal valve that is recessed a 1/2". remote canister stoves with a compatible fitting could use the new canister as well as the current butane cans. The new aluminum can with have a weighted hose on the inside so that liquid fuel would be supplied to the stove without the need to invert the canister. Regular stove that are not compatible with liquid fuel would not fit the recessed valve which would help prevent accidents.

The new aluminum can could be filled with the current butane/propane fuel mix, pure propane (if thicker aluminum walls are used) or any mixture in-between. And if a long distance hiker stopped in a town to get extra supplies he would have to worry about not finding the new aluminum canisters. He could use standard butane canister instead.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: 100% propane in aluminuim canisters? on 03/10/2013 22:08:36 MDT Print View

Yes, I am fairly sure the Sievert canister is heavier than a Coleman Powermax canister. I did check at one stage.

Note that it does have a 7/16" NCEF threaded Lindal valve, so it would be immediately compatible with every remote canister stove on the market.

Donations of unused canisters eagerly sought... :-)

Cheers

steven franchuk
(Surf) - M
Re: Re: Re: 100% propane in aluminuim canisters? on 03/12/2013 00:07:36 MDT Print View

"Note that it does have a 7/16" NCEF threaded Lindal valve, so it would be immediately compatible with every remote canister stove on the market."

it might not be compatible with every remote canister stove on the market. I didn't realize this today but the higher pressure of a propane canister could cause some serious problems if used with current stoves. The greater pressure will give a a very big flame. You might have to turn the valve to minimum to get a reasonable sized flame. Then a small change in valve position might just turn it off. Also the hoses used on current remote canister stoves might fail or leak at the pressures associated with propane. Lighting the stove could cause an uncontrolled fire if the hose leaks.

I could be completely wrong. In fact I hope I am. I didn't know anything about the Sievert canisters until yesterday and at present I have found very little information about them. Has anyone actually made a stove for it or has anyone actually tried to use it on a standard butane remote canister stove?

I guess I should have looked at Jim's earlier link before I posted the above. He has used it with a conventional butane stove without any major problems.

Edited by Surf on 03/12/2013 00:24:08 MDT.

KEN LARSON
(KENLARSON) - MLife

Locale: Western Michigan
FYI on 03/12/2013 06:02:34 MDT Print View

Ken,
Thank you for being a valued Bernzomatic customer and we are happy to help with your question below. Unfortunately, this product was discontinued in a product line rebuild prior to Bernzomatic joining Worthington Industries in the fall of 2011. The power cell line and the torches that accompanied them are no longer available in the market. I would encourage you to visit a retailer or wholesaler such as Lowes, Home Depot or your local Plumbing Supply house and acquire a new torch with the updated features. If we can be of any more help, please call us at 866-928-2657.

Again, we apologize for any inconvenience this issue has caused you.

Kris Cooley
Consumer Specialist
Phone: 614-840-3468
Fax: 614-438-3083
Kris.Cooley@worthingtonindustries.com

Edited by KENLARSON on 03/12/2013 06:03:11 MDT.

David Thomas
(DavidinKenai) - MLife

Locale: North Woods. Far North.
Re: Re: Re: Re: 100% propane in aluminuim canisters? on 03/12/2013 08:14:36 MDT Print View

Steven, I wouldn't expect higher pressure to be an issue - only a good thing. Propane at 0F is like butane at (no data in front me now) something like 70F. Further, you expect butane to be controllable from 35F to 120F, right? That's a huge pressure range.

If they've got the right valve, no problem. You may assume more pressure difference across a valve makes for more fuel flow, but that's only true to a point. At high pressure, the fuel gas goes sonic and is mass limited, based on the cross-section of the current valve setting.

Propane will burn a little leaner in a stove tuned for butane. That may be a bit less BTU/hour at max flame. It would also put out less CO at altitude. But mostly, a butane-propane-mix stove will be fine with 0 to 100% propane.

Nick Gatel
(ngatel) - MLife

Locale: Southern California
Propane, butane, iso-blends on 03/12/2013 11:24:54 MDT Print View

The benefit (or problem) with propane is that its vapor pressure is ~ 5 times as great as butane or the iso blends. Here is a chart from the Zen Stoves website (http://zenstoves.net/Canister.htm)

vapor pressure chart

Any appliance (stove) needs to be constructed to handle the pressure of its intended fuel. This means that burners, fittings, seals, hoses, lines, fuel container, etc. must handle the maximum pressure of the fuel.

I am not a scientist, but have a lot of experience with propane appliances. Let’s look at how RV manufactures manage the high pressures of propane. Any appliance that is inside the RV must run on 11 inches water column pressure (less than 1 psi). That means the following appliances in my tent trailer operate at 11” WC: 13.5K btu furnace, 6 gallon water heater, LPG refrigerator/freezer, and 3 burner stove/oven. How do I know this is the actual pressure? I have measured it with a manometer (below).

manometer

The appliances in my tent trailer are all known as low pressure appliances. The pressure is dropped from the LPG tanks to the camper via a pressure regulator.

Now let’s talk about outdoor propane appliances. Most are rated at 13-16 psi, and all include a built in pressure regulator. I have never seen a butane/iso stove canister stove with a pressure regulator.

coleman stove

Above: This is a Coleman propane stove and the regulated pressure is 16 psi.
You can run this stove off a bulk propane tank, but you MUST purchase a HIGH pressure hose rated at well over 200 psi.


baby q

Above: This is an interesting one, a Weber Baby Q Grill. My testing found that it is a low pressure stove operating at under 1 psi. The reason it works so well is that the grill is enamel coated cast iron (heavy). Given it is a low pressure appliance, I was able to remove the regulator and connect it directly to the outside quick connector on my tent trailer, which has 11" WC pressure.


lpg quick fitting
Above: regulator removed and replaced with a quick fitting.

lpg fitting and hose
Above: Hose connector to the camper.

baby q and stove
Above: low pressure appliances connected to tent trailer.

So why am I posting pictures of RV propane appliances? Because I know the operating specifications and can verify the pressures.


When it comes to backpacking stoves I am going to use the stove that works for the conditions I am going to encounter. In winter snow conditions I am going to use a Wind Pro II (inverted) or a MSR Dragon Fly. Those are the right tools for me, and I am going to use the fuels that are intended for each stove by the stove manufacturer; and I am going to follow the operating and maintenance procedures put forth by the manufacturer. That is why I have never had the "common" problems folks have with liquid stoves to include a Svea 123. There are too many things that can go wrong when you are out in the field using "jury-rigged" equipment, especially if one is tired and cold.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Re: 100% propane in aluminuim canisters? on 03/12/2013 15:10:01 MDT Print View

> I didn't realize this today but the higher pressure of a propane canister could
> cause some serious problems if used with current stoves.
This might be so in principle, but it is unlikely in practice. There are two areas which might be of concern: the hose, and the valving. (Disclaimer: these are personal opinions, not BPL statements.)

Hose pressure
This would be higher with propane, but the hoses used are mostly small-bore and will take an order of magnitude more pressure than is present. I say 'mostly' - there are some Asian remote canister stoves which seem to have poor-quality hoses and they might fail. I just don't know about them. Caution with them.
I addition, the braid overwrap will add enormous strength to the hoses. The burst pressure on a real (good) hose with braid would be extremely high.

Valving
The higher pressure will alter the valving of course. If the design of the valve is such that the stove used goes from off to full power in a quarter turn, then control will become more tricky. However, recent designs have been made with a much more gradual taper so that several turns are required. In this case the valving with propane will be more sensitive but easily controlled.

> standard butane remote canister stove?
No such thing really. The screw-thread canisters usually contain a butane/propane mix, with a higher pressure than plain butane.

The only change which might be needed when running on 100% propane would be a slight reduction in the size of the air inlet holes. Just blocking them slightly with a few turns of wire would be enough - if needed.

Cheers

Hikin' Jim
(hikin_jim)

Locale: Los Angeles, CA, USA
Re: Re: Re: Re: Re: 100% propane in aluminuim canisters? on 03/12/2013 23:45:46 MDT Print View

Nick,

Caution is a good thing, but I've experimented with 100% propane in a couple of different forms for my backpacking stoves with no ill effect. It actually works pretty well. I haven't tried them in hot weather, but for that I'd probably just stick with butane or a propane/butane blend.

HJ
Adventures in Stoving

anders ahrsjo
(anders.ahrsjo@gmail.com) - M

Locale: Sweden
Re: Re: Re: 100% propane in aluminuim canisters? on 03/20/2013 15:33:53 MDT Print View

Until 2011 you could get 70% propan/30% Butan mix in alu cans here in Sweden.
About 210 gram gas in a 100 gram spray can with Lindahl valve.
Excellent vinter gas for a Primus EtaPack Lite stove.
I've just packed a few for a trip north (16 h train and 2 h bus).
CheersBiltema gas with 70% propanNote EN 417 standard and Propan 70%. Butan 30%.