fuel consistency

Stu said:

Was wondering if there is a burn difference (better, hotter, last longer?
etc) of the two fuel cannister types.

MSR do an 80/20 mix isobutane/propane
Coleman+Snowpeak do an 70/30 mix butane/propane mix

so is isobutane better than butane?
is 70/30 better than 80/20? will it make
a difference when the cannister is low on pressure? etc

just learnt that snowpeaks is butane/lpgas

argh so now there is

butane/propane
isobutane/propane
butane/lpg

jetboil runs iso/pro but I dont know the % mix...

--
-- Stu

"Stu" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Was wondering if there is a burn difference (better, hotter, last longer?
etc) of the two fuel cannister types.

MSR do an 80/20 mix isobutane/propane
Coleman+Snowpeak do an 70/30 mix butane/propane mix

so is isobutane better than butane?
is 70/30 better than 80/20? will it make
a difference when the cannister is low on pressure? etc

anyone know the technical details? 🙂

I know this is a really [censored] answer and probably not worth the bandwidth
but...
I'm sure I read that one of them burns much better at altitude, although I
can't remember which one. So there's a difference at least......

"Treefrog" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

"Stu" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Was wondering if there is a burn difference (better, hotter, last longer?
etc) of the two fuel cannister types.

MSR do an 80/20 mix isobutane/propane
Coleman+Snowpeak do an 70/30 mix butane/propane mix

so is isobutane better than butane?
is 70/30 better than 80/20? will it make
a difference when the cannister is low on pressure? etc

anyone know the technical details? 🙂

I know this is a really [censored] answer and probably not worth the bandwidth
but...
I'm sure I read that one of them burns much better at altitude, although I
can't remember which one. So there's a difference at least......

Propane is added to the mix to improve low pressure burning - this includes
high altitude and low temperature. I recall turning on an old Camping Gaz
stove in Braemar one cold winter evening and hearing a hissss as the air
rushed in!!

druidh

The message <[email hidden]>
from Stu <[email hidden]> contains these words:

Quoted message said:

argh so now there is

Quoted message said:

butane/propane
isobutane/propane
butane/lpg

I'm no chemist but my dictionary would have it that lpg (liquefied
petroleum gas) is propane or butane liquefied under pressure.

Isobutane took a little more chasing down through iso and isomer to
isomerism - the existence of 2 or more compounds having the same
molecular formula but a different arrangement of atoms within the
molecule.

So it looks very much as if the increasingly fancy names are nothing
more than window dressing intended to add mystique to an otherwise dead
common product.

Oh yes Butane - a colourless flammable gaseous alkane that exists in 2
isomeric forms, both of which occur in natural gas. The stable isomer,
n-butane, is used mainly in the manufacture of rubber and fuels. (such
as Calor Gas). Formula C4H10.

and Propane - a colourless flammable gaseous alkane found in petroleum
and used as a fuel. Formula CH3CH2CH3.

<from Collins>

--
Roger Chapman so far this year 5 summits
New - 5 (Marilyns 0, Sweats 0, Outlying Fells 5)
Repeats - 0 (Marilyns 0, Sweats 0, Wainwrights 0, Outlying Fells 0)

Bitstring <[email hidden]>, from the wonderful person
Treefrog <[email hidden]> said

Quoted message said:

"Stu" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Was wondering if there is a burn difference (better, hotter, last longer?
etc) of the two fuel cannister types.

MSR do an 80/20 mix isobutane/propane
Coleman+Snowpeak do an 70/30 mix butane/propane mix

so is isobutane better than butane?
is 70/30 better than 80/20? will it make
a difference when the cannister is low on pressure? etc

anyone know the technical details? 🙂

I know this is a really [censored] answer and probably not worth the bandwidth
but...
I'm sure I read that one of them burns much better at altitude, although I
can't remember which one. So there's a difference at least......

Propane will have a higher vapour pressure at any given temperature,
since it's 'more gaseous'. The hydrocarbon table goes methane, ethane,
propane, butane, pentane, hexane, heptane, octane, nonane, decane .. and
so on. Hexane is liquid at room temperature/pressure. Pentane is so/so.
Methane and Ethane require silly pressure to liquefy, so are not
suitable for lightweight canisters. Octane .. well, that's pretty much
'vanilla' petrol. Keep on going and eventually you get to viscous
liquids and waxy solids .. think candles.

afaik, Isobutane and butane burn equally well, and I can't imagine
there is anything but a fractional difference.

--
GSV Three Minds in a Can
Outgoing Msgs are Turing Tested,and indistinguishable from human typing.

"Roger" <[email hidden]> wrote

Quoted message said:

Isobutane took a little more chasing down through iso and isomer to
isomerism - the existence of 2 or more compounds having the same
molecular formula but a different arrangement of atoms within the
molecule.

So it looks very much as if the increasingly fancy names are nothing
more than window dressing intended to add mystique to an otherwise dead
common product.

Oh yes Butane - a colourless flammable gaseous alkane that exists in 2
isomeric forms, both of which occur in natural gas. The stable isomer,
n-butane, is used mainly in the manufacture of rubber and fuels. (such
as Calor Gas). Formula C4H10.

If I can remember it correctly without bothering to look it up, n-butane has
the 4 carbon atoms arranged in a straight chain, iso-butane has a line of 3
carbon atoms in a straight chain with the 4th coming off the middle one. In
more modern nomenclature n-butane is just butane and iso-butane is actually
called 2-methylpropane which might sound confusing but is actually quite
logical once you understand the system. As far as burning goes they should
be pretty much the same I'd guess.

In article <[email hidden]>,
[email hidden] says...

Quoted message said:

"Roger" <[email hidden]> wrote

Quoted message said:

Isobutane took a little more chasing down through iso and isomer to
isomerism - the existence of 2 or more compounds having the same
molecular formula but a different arrangement of atoms within the
molecule.

So it looks very much as if the increasingly fancy names are nothing
more than window dressing intended to add mystique to an otherwise dead
common product.

Oh yes Butane - a colourless flammable gaseous alkane that exists in 2
isomeric forms, both of which occur in natural gas. The stable isomer,
n-butane, is used mainly in the manufacture of rubber and fuels. (such
as Calor Gas). Formula C4H10.

If I can remember it correctly without bothering to look it up, n-butane has
the 4 carbon atoms arranged in a straight chain, iso-butane has a line of 3
carbon atoms in a straight chain with the 4th coming off the middle one. In
more modern nomenclature n-butane is just butane and iso-butane is actually
called 2-methylpropane which might sound confusing but is actually quite
logical once you understand the system. As far as burning goes they should
be pretty much the same I'd guess.

I knew doing a chemistry degree would come in handy one day.

So it's a shame that now that time has come I can't remember much about
it! Though the above does seem to ring a few bells.

--
Darren
mail to darren not ng

"Darren G" <[email hidden]> wrote

Quoted message said:

I knew doing a chemistry degree would come in handy one day.

So it's a shame that now that time has come I can't remember much about
it! Though the above does seem to ring a few bells.

A lot of the chemistry I know has been self taught on a need to know basis
for work purposes. Certainly didn't learn much in A-levels or 4 years of
higher education (metallurgy), I was only doing just enough to not get
kicked out which happily didn't turn out to be an awful lot at all.

In article <[email hidden]>,
[email hidden] says...

Quoted message said:

"Darren G" <[email hidden]> wrote

Quoted message said:

I knew doing a chemistry degree would come in handy one day.

So it's a shame that now that time has come I can't remember much about
it! Though the above does seem to ring a few bells.

A lot of the chemistry I know has been self taught on a need to know basis
for work purposes. Certainly didn't learn much in A-levels or 4 years of
higher education (metallurgy), I was only doing just enough to not get
kicked out which happily didn't turn out to be an awful lot at all.

now that rings a bell too.

AND I have the certificate to prove I did the bare minimum!!

--
Darren
mail to darren not ng

In message <[email hidden]>, druidh
<[email hidden]> writes

Quoted message said:

"Treefrog" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

"Stu" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Was wondering if there is a burn difference (better, hotter, last longer?
etc) of the two fuel cannister types.

MSR do an 80/20 mix isobutane/propane
Coleman+Snowpeak do an 70/30 mix butane/propane mix

so is isobutane better than butane?
is 70/30 better than 80/20? will it make
a difference when the cannister is low on pressure? etc

anyone know the technical details? 🙂

I know this is a really [censored] answer and probably not worth the bandwidth
but...
I'm sure I read that one of them burns much better at altitude, although I
can't remember which one. So there's a difference at least......

Propane is added to the mix to improve low pressure burning - this includes
high altitude and low temperature. I recall turning on an old Camping Gaz
stove in Braemar one cold winter evening and hearing a hissss as the air
rushed in!!

No, propane is needed at low temperatures at low altitudes as it has a
much lower boiling temperature than butane. Butane cartridges work fine
at high altitudes even when it's cold, which is why Himalayan
mountaineers used to use Camping Gaz stoves without problems, puzzling
those of us who had difficulties with them in British winters.

In message <[email hidden]>, Chris Street
<[email hidden]> writes

Quoted message said:

Stu said:

Was wondering if there is a burn difference (better, hotter, last longer?
etc) of the two fuel cannister types.

MSR do an 80/20 mix isobutane/propane
Coleman+Snowpeak do an 70/30 mix butane/propane mix

so is isobutane better than butane?
is 70/30 better than 80/20? will it make
a difference when the cannister is low on pressure? etc

anyone know the technical details? 🙂

Definitions.

lpg = liqufied petroleum gas. Covers methane, ethane, propane, butane,
corresponding alkenes and alkynes and isomers. For camping though the only
ones you will be interested in will be propane, butane and "isobutane"

propane - gas consisting of three carbon atoms in a line with eight
hydrogen atoms hanging off them CH3-CH2-CH3

butane - four carbon atoms, ten hydrogen CH3-CH2-CH2-CH3

iso butane is more correctly termed as 2-methylpropane and has a branched
structure rather than a straight one

CH3-CH-CH3
|
CH3

Note that it still has the same number of carbon and hydrogen atoms.

This change in shape has a profound change in the physical properties. From
my copy of the Rubber Book 72nd Edition, butane is listed with a boiling
point of 0.5C, propane is listed at -42C.

Intermoleculare forces called van der Waals forces keep alkanes together as
a liquid. These are weak forces and don't do an especially good job.
However as the length of a molcule increases they do a better job - methane
the shortest boils at somthing like -167C

By looking at the overall length of isobutane you can see it's considerably
shorter than normal butane. Hence the Van der Waals forces are less and it
should boil at a lower temperture. It does and it actually boils at -11.7C

These boiling points define the absolute minimum temperatures you can burn
them at - below that of course there is no gas. However even at
temperatures above this the gas pressure is insufficient to generate a
large amount of pressure in the jet so although a flame can be lite it is
aggravatingly small.

At -1C butane will not burn. Isobutane with it's -11.7 boiling point will
and can be used quite successfully as a fuel. There is no change in gas
density and a very small change in jet velocity so it can be used in
standard butane jetted burners without problems.

By adding propane to a mix of butane you change the physical properties of
the mixture. Rather than having a 4 carbon long chain next to another four
carbon long, you could be next to a three carbon long chain. This reduces
the effective Van der Waals forces, drving down the boiling point. I have
no data for propane/butane mixes handy but a simple bicomponent system like
this will probably not deviate from ideality much and I would expect a
30:70 mix to be 30% of the way from 0.5 to -42 which is about -12.5

By adding isobutane and propane together it's much more effective as you
start from -11.7, so a 30:70 mix would boil at about -21C

Chris, thanks for the clear technical info.

In practice I have found that butane/propane mixes, whatever the
proportion and whether they contain isobutane or not, don't work well
below -5C without the cartridge being warmed and kept warm. When a
cartridge is full it works quite well at sub zero temperatures but the
performance quickly falls off. A common reason given for this is that
the propane burns off first, though I have seen arguments that this is
not so.

The only exceptions I know to this are the Coleman Max 60:40
butane/propane cartridges, which will only work with Coleman X series
stoves. These cartridges have an internal tube and feed liquid fuel, not
gas, to the stove. The fuel is warmed by a preheat tube that runs
through the burner. I've used Max cartridges down to -12C without any
loss in performance even right up to the last few seconds of fuel. I've
also left my the stove and cartridge outside over night on the ground so
both are covered with frost and then lit the stove and used it without
difficulty.

I reckon the Coleman X stoves and Max cartridges are the only ones
suitable for use in consistently sub zero weather. Unfortunately finding
the cartridges in the UK is very difficult. One supplier is
http://www.gazzaproducts.co.uk

"Chris Townsend" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

In message <[email hidden]>, druidh
<[email hidden]> writes

Quoted message said:

"Treefrog" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

"Stu" <[email hidden]> wrote in message
news:[email hidden]...
>
> Was wondering if there is a burn difference (better, hotter, last
> longer?
> etc) of the two fuel cannister types.
>
> MSR do an 80/20 mix isobutane/propane
> Coleman+Snowpeak do an 70/30 mix butane/propane mix
>
> so is isobutane better than butane?
> is 70/30 better than 80/20? will it make
> a difference when the cannister is low on pressure? etc
>
> anyone know the technical details? 🙂

I know this is a really [censored] answer and probably not worth the bandwidth
but...
I'm sure I read that one of them burns much better at altitude, although
I
can't remember which one. So there's a difference at least......

Propane is added to the mix to improve low pressure burning - this
includes
high altitude and low temperature. I recall turning on an old Camping Gaz
stove in Braemar one cold winter evening and hearing a hissss as the air
rushed in!!

No, propane is needed at low temperatures at low altitudes as it has a
much lower boiling temperature than butane. Butane cartridges work fine at
high altitudes even when it's cold, which is why Himalayan mountaineers
used to use Camping Gaz stoves without problems, puzzling those of us who
had difficulties with them in British winters.

Aha - must've been even colder than I thought then. Anyone else suffer
frostbite while holding a gaz stove in their hands to warm it up??

druidh

In message <[email hidden]>, druidh
<[email hidden]> writes

Quoted message said:

"Chris Townsend" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

In message <[email hidden]>, druidh
<[email hidden]> writes

Quoted message said:

"Treefrog" <[email hidden]> wrote in message
news:[email hidden]...
> "Stu" <[email hidden]> wrote in message
> news:[email hidden]...
>>
>> Was wondering if there is a burn difference (better, hotter, last
>> longer?
>> etc) of the two fuel cannister types.
>>
>> MSR do an 80/20 mix isobutane/propane
>> Coleman+Snowpeak do an 70/30 mix butane/propane mix
>>
>> so is isobutane better than butane?
>> is 70/30 better than 80/20? will it make
>> a difference when the cannister is low on pressure? etc
>>
>> anyone know the technical details? 🙂
>
> I know this is a really [censored] answer and probably not worth the bandwidth
> but...
> I'm sure I read that one of them burns much better at altitude, although
> I
> can't remember which one. So there's a difference at least......
>
>
Propane is added to the mix to improve low pressure burning - this
includes
high altitude and low temperature. I recall turning on an old Camping Gaz
stove in Braemar one cold winter evening and hearing a hissss as the air
rushed in!!

No, propane is needed at low temperatures at low altitudes as it has a
much lower boiling temperature than butane. Butane cartridges work fine at
high altitudes even when it's cold, which is why Himalayan mountaineers
used to use Camping Gaz stoves without problems, puzzling those of us who
had difficulties with them in British winters.

Aha - must've been even colder than I thought then. Anyone else suffer
frostbite while holding a gaz stove in their hands to warm it up??

The old Camping Gaz Bleuet stoves with piercable butane cartridges
wouldn't work properly if it was below +5C. Current Campingaz (as they
now call themselves) cartridges are 80:20 butane/propane and work a
little better in the cold.

Several years ago I led a ski tour in the Tombstone Mountains in the
Yukon Territory, just south of the Arctic Circle. Due to airline
restrictions we weren't able to take liquid fuel stoves. In the Yukon
resealable Campingaz cartridges were the only ones available so I took
three Campingaz stoves. Temperature fell to -25C at times and we had to
melt snow occasionally. Cooking for ten on these stoves at those
temperatures was not fun! Cartridges had to be warmed up with hands and
inside clothing and sleeping bags. We had one hose attached stove, which
I used with the cartridge in my sleeping bag. All the cartridges were
just about useless when half empty.

In message <[email hidden]>, Chris Street
<[email hidden]> writes

Quoted message said:

Chris Townsend said:

In message <[email hidden]>, druidh
<[email hidden]> writes

Quoted message said:

"Chris Townsend" <[email hidden]> wrote in message
news:[email hidden]...
> In message <[email hidden]>, druidh
> <[email hidden]> writes
>>
>>"Treefrog" <[email hidden]> wrote in message
>>news:[email hidden]...
>>> "Stu" <[email hidden]> wrote in message
>>> news:[email hidden]...
>>>>
>>>> Was wondering if there is a burn difference (better, hotter, last
>>>> longer?
>>>> etc) of the two fuel cannister types.
>>>>
>>>> MSR do an 80/20 mix isobutane/propane
>>>> Coleman+Snowpeak do an 70/30 mix butane/propane mix
>>>>
>>>> so is isobutane better than butane?
>>>> is 70/30 better than 80/20? will it make
>>>> a difference when the cannister is low on pressure? etc
>>>>
>>>> anyone know the technical details? 🙂
>>>
>>> I know this is a really [censored] answer and probably not worth the bandwidth
>>> but...
>>> I'm sure I read that one of them burns much better at altitude, although
>>> I
>>> can't remember which one. So there's a difference at least......
>>>
>>>
>>Propane is added to the mix to improve low pressure burning - this
>>includes
>>high altitude and low temperature. I recall turning on an old Camping Gaz
>>stove in Braemar one cold winter evening and hearing a hissss as the air
>>rushed in!!
>>
> No, propane is needed at low temperatures at low altitudes as it has a
> much lower boiling temperature than butane. Butane cartridges work fine at
> high altitudes even when it's cold, which is why Himalayan mountaineers
> used to use Camping Gaz stoves without problems, puzzling those of us who
> had difficulties with them in British winters.
>
Aha - must've been even colder than I thought then. Anyone else suffer
frostbite while holding a gaz stove in their hands to warm it up??

The old Camping Gaz Bleuet stoves with piercable butane cartridges
wouldn't work properly if it was below +5C. Current Campingaz (as they
now call themselves) cartridges are 80:20 butane/propane and work a
little better in the cold.

Several years ago I led a ski tour in the Tombstone Mountains in the
Yukon Territory, just south of the Arctic Circle. Due to airline
restrictions we weren't able to take liquid fuel stoves. In the Yukon
resealable Campingaz cartridges were the only ones available so I took
three Campingaz stoves. Temperature fell to -25C at times and we had to
melt snow occasionally. Cooking for ten on these stoves at those
temperatures was not fun! Cartridges had to be warmed up with hands and
inside clothing and sleeping bags. We had one hose attached stove, which
I used with the cartridge in my sleeping bag. All the cartridges were
just about useless when half empty.

Pot of hot water. Dunk gas bottle in it. If you hands can tolerate the
temperature of the water then the gas cartridge won't go bang or anything
daft like that.

Oh, we did that. The water and cartridge cooled down very, very quickly.

We also stood cartridges on top of pan lids on pas on a stove.

In message <[email hidden]>, Chris Street
<[email hidden]> writes

Quoted message said:

Chris Townsend said:

Chris, thanks for the clear technical info.

In practice I have found that butane/propane mixes, whatever the
proportion and whether they contain isobutane or not, don't work well
below -5C without the cartridge being warmed and kept warm. When a
cartridge is full it works quite well at sub zero temperatures but the
performance quickly falls off. A common reason given for this is that
the propane burns off first, though I have seen arguments that this is
not so.

It's wrong for the same reason that a bottle of vodka doesn't separate into
alcohol and water. Propane and butane are perfectly miscible and they mix
entirely thus the evaporative surface consists of a mixture of liquids -
therefore you get a gaseous mixture as well.

What then causes the rapid fall of in performance? Just the pressure in
the cartridge falling?

Quoted message said:

Quoted message said:

The only exceptions I know to this are the Coleman Max 60:40
butane/propane cartridges, which will only work with Coleman X series
stoves. These cartridges have an internal tube and feed liquid fuel, not
gas, to the stove. The fuel is warmed by a preheat tube that runs
through the burner. I've used Max cartridges down to -12C without any
loss in performance even right up to the last few seconds of fuel. I've
also left my the stove and cartridge outside over night on the ground so
both are covered with frost and then lit the stove and used it without
difficulty.

It's just like a Primus stove or other self vaporising liquid fuel stoves
then. It'll work below the boiling point of the gas mix assuming you can
get it to light initially - one of those handheld turbo lighters should be
enough to get it going. Personally I'd be a little leery of using it with
LPG that wants to become an explosive gas without the benefits of heat
myself....

I've never had any problem getting it to light. A match or ordinary
lighter works fine even at -12C. As soon as you open the valve gas comes
out, as with any gas stove.

Quoted message said:

Quoted message said:

I reckon the Coleman X stoves and Max cartridges are the only ones
suitable for use in consistently sub zero weather. Unfortunately finding
the cartridges in the UK is very difficult. One supplier is
http://www.gazzaproducts.co.uk

I just use a Coleman petrol stove. although it's a pain refuelling now I
have a diesel car. I'm looking for a decent diesel stove - any thoughts on
the Optimax's or should I just save up and get an MSR dragonfly
burn-anything sort of stove...?

I reckon the Optimus Nova is the best liquid fuel stove around at the
moment. I've used it on two month long walks without problem. It is
supposed to burn diesel, though I haven't tried this. It works fine with
paraffin.

The Dragonfly doesn't burn diesel - at least it's not listed as a fuel
by MSR. The XGK Expedition is the only MSR stove said to work with
diesel. The XGK is a good stove and certainly works well with paraffin,
petrol and even some smoky gunk called white spirit I found in a hut in
Norway. It's not as clean or easy to use as the Nova though. It doesn't
simmer easily either, which the Nova does.

Quoted message said:

I just use a Coleman petrol stove. although it's a pain refuelling now I
have a diesel car. I'm looking for a decent diesel stove - any thoughts on
the Optimax's or should I just save up and get an MSR dragonfly
burn-anything sort of stove...?

Don't know anything about the Optimax, but I've an Optimus Nova which is
supposed to be able to burn diesel though I haven't tried it. It isn't
the hottest or the most efficient stove on the market but it does have
the redeeming feature that it simmers like a champ without sputtering or
going out or otherwise needing to be fussed over.

hth,

Boo

The message <[email hidden]>
from Chris Townsend <[email hidden]> contains these words:

<Chris Street>

Quoted message said:

Quoted message said:

It's wrong for the same reason that a bottle of vodka doesn't separate into
alcohol and water. Propane and butane are perfectly miscible and they mix
entirely thus the evaporative surface consists of a mixture of liquids -
therefore you get a gaseous mixture as well.

If you are foolish enough to keep your vodka in an unsealed container
why shouldn't the alcohol and water evaporate at different rates, they
have different boiling points?

Quoted message said:

What then causes the rapid fall of in performance? Just the pressure in
the cartridge falling?

I would have thought that was basic physics - latent heat of evaporation
(or whatever they call it these days). Turning the liquid into gas needs
a specific amount of energy which cools the remainder of the liquid. As
the reservoir is depleted there is less liquid to provide this heat and
the temperature of the remainder thus drops more quickly.

--
Roger Chapman so far this year 5 summits
New - 5 (Marilyns 0, Sweats 0, Outlying Fells 5)
Repeats - 0 (Marilyns 0, Sweats 0, Wainwrights 0, Outlying Fells 0)

druidh said:

"Chris Townsend" <[email hidden]> wrote in message

Quoted message said:

Quoted message said:

No, propane is needed at low temperatures at low altitudes as it has a
much lower boiling temperature than butane. Butane cartridges work fine at
high altitudes even when it's cold, which is why Himalayan mountaineers
used to use Camping Gaz stoves without problems, puzzling those of us who
had difficulties with them in British winters.

Aha - must've been even colder than I thought then. Anyone else suffer
frostbite while holding a gaz stove in their hands to warm it up??

I only do that in a dire emergency. Normally the cartridge gets
chucked in my sleeping bag so it's nice and warm in the morning. If
you have a hose and tripod stove you can balance the cartridge on top
of the pan lid to get warmed by the waste heat.
--
Phil Cook looking north over the park to the "Westminster Gasworks"

Quoted message said:

Quoted message said:

Pot of hot water. Dunk gas bottle in it. If you hands can tolerate the
temperature of the water then the gas cartridge won't go bang or anything
daft like that.

Oh, we did that. The water and cartridge cooled down very, very quickly.

We also stood cartridges on top of pan lids on pas on a stove.

Why not try a vertical arrangement of several stoves so the ones below
warm the ones on top ? Braced with spare guylines it should be quite
feasible - a kind of culinary post office tower :-)

--
Boo