Nov 27, 2012 at 5:12 pm #1296525
Good evening Folks,
My apologies if this has been spoken about before but searched BPL with no luck.
I have two Jetboil canisters that I am trying to figure out how much gas is left in them.
The first one is a 100g canister which weighs in at 201g on my scales (I think it might be full, as cannot remember using it) and a 230g canister which weighs in at 316g (used 2 weeks ago to boil about 3 litres)
Anyone have any idea what these canisters weigh empty?
Thanks in advance,
StephenNov 28, 2012 at 3:06 am #1931667
@tjaardLocale: Minnesota, USA
My computer died, so can't get to my ger list, but you could go to the store and weigh the full ones, then subtract the weight of the gas, should give you a decent approximation .Nov 28, 2012 at 4:10 am #1931673
Unfortunately the nearest store is an hour away, I will call them and ask can they weigh them for me.
StephenNov 28, 2012 at 4:13 am #1931674
@jamesdmarcoLocale: Finger Lakes
Yeah, that is about right for a full canister, both the 4oz and 8oz. (100g is slightly less than 4oz and 230 is slightly more than 8oz.) I figure about 100% for canister weights vs gas weights for the smaller canisters. Larger canisters are more efficient but still weigh about 2/3 of the fuel weight.
I got 3.6-4.2oz amungst various manufacturors about 7 years ago.
I got 5.8 and 7.2oz between two different larger canisters 7 years ago.
They vary, even amung the same manufaturor. Fuel, metal thickness, rolling, sealing, valves, etc. Nowdays, they have dropped the ounce usage in favour of the metric weights. Coleman canisters were always the heaviest, as I remember.
You ALWAYS need to add the canister for the true fuel weights.
This is why I say that alcohol and canisters are about equivalent.
Ethanaol/Methanol blende is about 11000BTU/lb, but it only takes a 1oz bottle to carry up to 16floz.
A canister starts at about 22000BTU/lb but adding in 100% for the can, this drops it to about 11000BTU/lb. I usually figure about 13000BTU becuase it isn't quite 100% fuel/can and it is more efficient with the on/off&simmer valve.
For comparison, WG is around 17000BTU after adding in for the container. Kero is slightly higher. Hexamine or Esbit was about 12000-13000BTU(soot may drop this slightly.)Nov 28, 2012 at 4:28 am #1931675
Thanks very much for that information.
The trip is 3 nights and 3 full days so I might just bring the two cartiages as will be boiling water for each meal for hot drinks.
StephenNov 28, 2012 at 4:42 am #1931676
I never had a canister by JetBoil, but for other brands 100-110g canisters usually are 90-100 g when empty, and 220-230g are about 130-134g (one particular canister was 150g).Nov 28, 2012 at 4:44 am #1931677
@jamesdmarcoLocale: Finger Lakes
Yeah. Generally I find canisters less reliable than I would like. I would always bring a spare cartridge back when I was using them. No fun cooking over a camp fire in the rain.Nov 28, 2012 at 5:36 am #1931681
Not to point out the obvious, but is it not printed on the canister? Snow Peak canisters have the fuel weight printed on the top of the can in teeny tiny letters.Nov 28, 2012 at 5:51 am #1931685
That's very much Sergiy,
I hear you James, I was in a trip last winter where a buddies can stripped working.
It has the weight of the gas displayed on it but I need to know the empty weight time figure it how much gas is in them, I could always call Jetboil.
StephenNov 28, 2012 at 6:29 am #1931690
Just called Jetboil, they say a 100g can is 94g empty and a 230g is 126g empty.
So the small one is full and Large one is roughly 80% used.Dec 1, 2012 at 6:19 pm #1932466
I looked in my notes and found that the measured, total weight of the full small size canister I have (Snow Peak, IIRC) is 212 grams. The contents is 110 grams; leaving 102 grams as the "tare" weight of the canister.Dec 1, 2012 at 10:12 pm #1932504
An easy way to keep track of usage is, when you're done with your next trip, to just put a mark on your canister for each use. When you get to ten marks, get a new canister if your next trip is more than a couple nights. I find I get around 12 to 14 burns out of a small canister if I'm just boiling water.
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