Male bayonet Butane canisters: why so much cheaper

[Roger Caffin]

> The possible minimalism and efficiency would seem appealing.

I find it hard to imagine something more 'minimal' than a SnowPeak GS100 or a UL Gnat stove myself. And both of those are quite efficient. Just my thoughts.

Cheers

[al b]

Roger Caffin said
"I find it hard to imagine something more 'minimal' than a SnowPeak GS100 or a UL Gnat stove myself. And both of those are quite efficient. Just my thoughts."

I meant minimal in comparison to a remote stove (normally needed for a caldera style complete conic enclosure).

And I meant efficient (in wind) compared to a jetboil, surely the total enclosure in a cone means more efficient compared to a can top stove, hopefully similar to a jetboil but for less weight (hopefully)?

Here is a belated diagram.

[Nick Gatel]

Getting specifications on canisters and pressures is like searching for a needle in a haystack. But the green Coleman and blue Benz-o-matic canisters run high pressure devices such as Coleman stoves, lanterns, BBQ s, etc. These devices typically operate at around 15 to 20 psi. And you will find that the construction of the these canisters are much thicker than the material used for most BPing stove canisters.

Appliances inside an RV are required by law to operate at a max of 11 inches water column, which is approximately 1/2 psi. We are talking about stoves, heaters, ovens, and refrigerators.

If you look a the typical Coleman stove or lantern, you will see a fairly substantial regulator on them.

To provide an example, I have a Weber BBQ that I wanted to hook-up to my tent trailer's outside LPG connection. Knowing that the BBQ was designed to run at close to 20 psi, and my camper only provides 1/2 psi pressure, I removed the regulator from the BBQ. However I did not remove the jet inside the burner feed. Without the regulator and using low pressure, the BBQ works perfect. As an experiment I connected a Coleman canister to it, and the flame was a couple feet high!!!!

Looking at several of my BPing canister stoves, I suspect that these are also running around 1/2 psi. So I would never consider trying to adapt a standard canister without some sort of a regulator… which means a lot of weight.

Regarding refilling canisters. In the US it is against the law to transport or sell refilled canisters. Don't know if it is a true safety issue, or lobbying on the part of the canister manufacturers to protect their marketing. But if the BPing canisters are designed to hold 1/2 psi and you are connecting it to a 20 psi or greater canister, I would be wary. Just a disclaimer… I do not have the specs on BPing canister pressures.

Why are these Coleman and Benz-o-matic canisters cheaper? Supply and demand. Millions upon millions of them are sold yearly. And of course the blends may not be what we want for colder camping anyway.

[Hikin’ Jim]

Nick,

The 170g canisters that Alan is referring to are not the big 16.2oz/465g Coleman 100% propane type canisters.

The 170g canisters are much smaller and have a standard 7/16ths UNEF threaded connector just like a standard backpacking canister. They're a propane-butane blend, not just propane.

I agree that 100% propane has a vapor pressure that makes it unwieldy for backpacking, but the blended fuel canisters that Alan is talking about are actually quite practical. They're a size midway between the 113g and 227g sizes that are regularly available in the US, and the canister itself is lighter than standard backpacking canisters. I just wish I could find some in the US.

HJ

[Nick Gatel]

Jim,

Thanks for the clarification. To me grams are a some sort of communist plot and I can't convert well :)

But I recently got a scale in grams so I will be jointing the magical metrical mystery tour soon.

[Hikin’ Jim]

Alan,

Nice diagram. :)

I see what you're driving at. If the canister sits upright but outside the cone, then (maybe) you don't have the problem of potentially overheating the canister.

Two problems with your set up:
1. The attach point where the "nozzle" enters the cone is going to get HOT. I forsee melting here, particularly if there's any plastic in the torch head.
2. The flame is high on the pot, near the top of the cone. All that heat is going to concentrate in the top of the cone, and the cone is going to melt (assuming you're using a standard Aluminum cone).

A Ti cone might do better, but you'd still have the problem of melting at the attach point.

The other problem I see is one of heat distribution. You're heating the pot from one side only. I don't see that as efficient. I suppose it might work for boiling water, but that's about it. You'd need a Ti pot and a Ti cone, and you'd need to overcome the problem of overheating at the point where the torch head enters the cone.

Still, all that said, I suppose that the only way to really tell is to rig up a test. Perhaps if you could find an all metal torch head, you wouldn't have to worry about melting, but you would have to worry about thermal conduction back to the tank through the torch head. You'd have to monitor canister temperature very closely.

Your idea is very interesting. Let us know how it goes if you try something like this. Just be really careful about canister overheating.

HJ

[Bob Gross]

You could lay the canister over on its side, put the burner pipe through a hole on the cone wall, then have a 90-degree bend in the burner pipe with the burner pointed straight up at the bottom of the mug. That would be interesting.

–B.G.–

[Hikin’ Jim]

Unless the canister has a dip tube, you'd get some serious flaring. Still, I agree with Bob that being under pot would be more "interesting" if all the details could be worked out.

HJ

[al b]

HJ said
"being under pot would be more "interesting""

My thinking was a tall narrow pot has more surface area on the side than underside
so if flame hits the lowest side of pot then it may directly hit more. The cone can lift the pot high enough so that the flame hits the lower side of pot, as in my previous diagram.

Also, according to trail defigns once you enclose a pot in a cone the efficiency differences between narrow and wide pots disappear: because the hot gases just pass by the sides of the pot and heat there, so why not heat lowest part of side, and let spiralling, rising gases heat rest of it.

EDIT found this 120g almost all metal unit described as flare safe within a minute:
http://www.go-system.co.uk/catalog/product/view/id/266/category/22/

120g isn't too bad for an off the shelf idea, a Tony Beasely style MYOG version
could be lighter (and avoids needing remote hose).

Or if heating underneath is desired, keeping all else the same as original diagram, you could use a taller cone, and add an extension with 45/90 bend so gas fires upwards underneath pot: the cartridge would remain upright. Unfortunately, this now requires metalworking and gas knowledge to ensure safety, whereas I was hoping for a more off-the-shelf MYOG idea.

EDIT just found this:

Unfortunately weighs 309g, but proves blow torch can run on side (if you think about it, they are hand held, so should need to be able to cope with being non-vertical
(BUT some mention flare safe as an option, so need to check)
a Tony Beasely style MYOG version could be lighter (and avoids needing remote hose).

EDIT: I hope it can be lit in position shown, it would be better with control on side.
EDIT: control knob would need a peg thru it as shown, with matching holes in said plastic knob. Plastic parts look cosmetic, but would need checked.

On a different note, the flat stoves that begot the cheap aerosol cannisters are somewhat heavy, it seems strange no one has made a lightweight one, sort of like the GasMate adaptor (in http://zenstoves.net/Canister.htm, which also seems to show a picture of the very thing under Side Mounted Stoves, although it looks a bit heavy)

[al b]

I noticed that Hiking Jim had the aforementioned (in my previous post) gasmate style adaptor on his blog:

perhaps it would be worth a stove of the week spot on said blog.

I also found this smaller Camping Gaz torch which can lie on side (presumably after warm up):

so could be lit, then set on side (beside cone) to heat under pot (in cone).

It has quite a long "snout"

NB by on side I would envisage the control valve knob facing away from cone.

NB this idea is vapourware and only to be tried if considered as safe.

[Hikin’ Jim]

If you have a titanium cone (not aluminum!), it might work. I don't see that it would be particularly efficient at heat transfer. It seems like heating the pot from the bottom is the logical choice in terms of efficiency.

That's not a bad idea to devote one of my blog posts to some of the various adapters I have.

HJ

[al b]

That burner on its side should be heating the pot from below: hence the new post upon its discovery.

[Hikin’ Jim]

Hmm. Interesting. Still need a Titanium cone. Are you going to try it out?

HJ

[al b]

I might.

[al b]

On 2nd thoughts, I won't try it, because even when can is lying on its side, it would have liquid feed only up till liquid level falls beneath valve.

However, although even though no off the shelf solution exists, the idea was posted for manufacturers and those who make their own stoves, and
now
I have a (hopefully) better idea of how to get total cone enclosure, and liquid feed (for cold weather), without needing a flexible hose: here is the thread —

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=56523

Did Hank roberts 2 flare on start-up (when used with original hank roberts canister)?

[Hikin’ Jim]

Yes, the Hank Roberts type stoves (which were sold under multiple names such as EFI, Browning, Gerry, etc.) did flare until they warmed up. The instructions state that the gas should be kept on low until the stove warmed up.

But once they warm up, they're fine on liquid feed butane.

HJ
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