Cost of canister gas?

[CasualNerd]

Has anyone actually lit one yet, to confirm that they're not just full of water?

Yeah burns just as you'd expect. They look / feel like every quality brand name I've used previously.

[johnrs]

Guys
Where did you order the bulk Gasmate canisters??
Can't see it in the thread.
I am in NSW.
Thanks
John

[Nuts]

https://www.outdoorsdomain.com.au (shrug)

GPS they were 75/25 here as well (last year).. so a change in the mix.

[Warin]

Guys
Where did you order the bulk Gasmate canisters??
Can't see it in the thread.

On page 1 of this thread about 1/3rd the way down the page

Meanwhile:

https://www.outdoorsdomain.com.au/gasma ... gJ0dPD_BwE

Note .. 230g may be sold out at the moment. But you might still be able to order them, just a longer wait for stock to arrive and then to be delivered.

Nuts has already posted just above .. but this gives where you can see the original post .. so you might improve your detective skills

[GPSGuided]

GPS they were 75/25 here as well (last year).. so a change in the mix.

I wonder why they changed the mix? Supplier change? Market differentiation? Climate change?

[Mark F]

I suspect that the reduction in propane from 30% to 25% is needed to allow for the higher partial pressure generated in the move from n-butane to iso-butane. Checking Google for images of canister the 30% propane canisters are labeled as having butane rather than iso-butane, Personally I much prefer the propane/iso-butane blend as the entire canister will work down to well below zero even if the propane is largely exhausted. This suggests that either blend , 80/20 n-butane/propane or 75/25 iso-butane/propane which both have very similar temperature/pressure curves, deliver internal pressures that are at the upper limit of the canister specifications.

[Warin]

internal pressures that are at the upper limit of the canister specifications.

Zen and the design production process. Ommm
The design engineer and lawyer will have a safety factor in the strength of the canister.
The production engineer and accountant will reduce that safety factor of the canister to reduce costs.
As the person to oversee the production the production engineer has the last say.
Thus thin canisters.

(Ref: Zen and the Art of Motorcycle Maintenance)

[GPSGuided]

Personally I much prefer the propane/iso-butane blend as the entire canister will work down to well below zero even if the propane is largely exhausted.

Concur. Propane/iso-Butane in 25/75 mix is a sweet spot, one that sucked me into this deal.

[Nuts]

GPS they were 75/25 here as well (last year).. so a change in the mix.

I wonder why they changed the mix? Supplier change? Market differentiation? Climate change?

The NZ mix? Perhaps that is a newer version, i'm not sure. I'd suspect pricing first. The 75/25 mix works fine, through our range of conditions.

[GPSGuided]

The NZ mix? Perhaps that is a newer version, i'm not sure. I'd suspect pricing first. The 75/25 mix works fine, through our range of conditions.

Yes, I was referring to the difference in the mix ratio b/n NZ and AU of the same product.

By logic, one would have expected the higher propane ratio be supplied to NZ for the colder climate and potential higher altitude of walk routes.

[skibug]

Mark F wrote:

"... This suggests that either blend , 80/20 n-butane/propane or 75/25 iso-butane/propane which both have very similar temperature/pressure curves, deliver internal pressures that are at the upper limit of the canister specifications."

Roger Caffin, not surprisingly, has done a lot of research on canister pressure and failures, including experiments in his (rural) backyard, heating canisters to their rupture point inside an old kiln. He published in Backpacking Light (https://backpackinglight.com/exploding_ ... verheating) some years ago, which I read at the time (as a subscriber at the time), but no longer can access. But from memory, he found that canisters are engineered to be safe up to at least 50 degrees, as they may be be transported in conditions up to that. In his stress tests, I seem to remember he found that it was only above (usually well above) 80 degrees(?) that they would fail, and even then not with "explosions" but more like powerful venting. As 50 degrees is reasonably hot to the touch, I concluded that so long as I can comfortably touch the hottest part of the canister, it was reasonably safe - this is assuming the canister is not corroded, or has dents or other imperfections. With my cooking set up, including a windshield which is loosely wrapped, I have never felt at risk.

See also:

https://bushwalkingnsw.org.au/clubsites ... ch.htm#Hot

Skibug

[Mark F]

ski bug - I agree and my posts were based on Rogers findings and other information. The point of my posts was in response to others who seemed to want to increase the propane level to well above the 25% in the propane/iso-butane blend and thus move into what I consider dangerous territory as do the standard setters. I have no fears for my own setup which also includes a windshield.

[GPSGuided]

Looks like Outdoors Domain has received new stock of those 230g canisters and our bulk order here in Sydney will be shipped soon.

At present, we still have 12 spare cans unallocated (at $3 each) for those who are interested.

[MeanderingFlyFisher]

M'dog, the one you linked, and indeed the experiments/discussions on here were for use with butane, mostly decanting between Iso cans or from cheaper butane sources..

Iv'e used LPG (adaptors and) 1kg cylinders and they are very heavy walled.

Let's know how you go (I don't know enough else to comment further).

Meanwhile:

https://www.outdoorsdomain.com.au/gasma ... gJ0dPD_BwE

?

These guys still have these available as I just received a box today.Gone up a bit I think but $100 delivered for 24 is still a lot better than $10-$14 a can.