Newb question about Isobutane

[Chris T]

Hey there, I’m pretty new at this. I started backpacking in late April and I am taking my 4th overnighter (2 day) this weekend. So I guess that means I’ve been out 6 days so far, so 6 hot meals plus morning coffee. How do I know when my Isobutane canister is empty? If I wanted to weigh it, how much does the fuel itself vs the canister weigh? Like if I weigh it and its 3.5 oz instead of 4 does that make it say half full or nearly empty?

Sorry if this seems like a ridiculously basic question. I’ve googled and most people keep track of cook time. Because of my addiction to instant coffee in the morning, I really haven’t. Any ideas?

[Matthew / BPL]

Some weights listed in this thread.

[Jerry Adams]

“8 oz” canisters weigh about 5 ounces empty

“4 oz” canisters weigh about 3 ounces

It varies a little by brand and maybe every few years the same brand can change a little.  When you run a canister empty you can weigh it and be more accurate

If a “4 oz” container weighs 7 oz it’s full.  5 oz – half full.  etc.

The last 1 ounce of a canister gets hard to empty, the stove starts running very slowly.  You might consider a canister with only 1 ounce, or 1/2 ounce “empty” because it’s so slow

sorry, I can’t think of anything clever to say in response to your question about it being a ridiculously basic question : )

[Jerry Adams]

Matthew’s post is a bit dated.  Canisters have come down a bit in weight since then.  To save manufacturing cost, not as a service to ultralight backpackers : )

[Matthew / BPL]

Heh, good catch. I didn’t notice the date.

Not knowing how much fuel is left in my canister is a large part of why I prefer Esbit (or alcohol) as a fuel source.

[Matthew / BPL]

Chris, what size/brand of canister are you using? If it’s a 220(200?) Snow Peak I have some empties here that I haven’t gotten around to recycling and I can weigh one for you.

[Chris T]

I’m using the MSR 4 oz canisters, the small ones. For some reason I thought the thing was 4 oz full so I am glad I asked! I can build an oz or two for wiggle room. So as long as its over say 5 oz now I can probably be ok for two nights. I certainly won’t starve in 2 nights! Ha. Every time I have gone out I’ve been able to get some weight off my pack! I don’t want to break my streak by carrying an extra. Hehehe.

[Jerry Adams]

If you carry an extra ounce, then you can just assume 220/200 canisters (8 ounce) weigh 5 ounces empty : )

[Matthew / BPL]

I don’t have any of those to weigh for you, Chris :(

[Gary Dunckel]

OK, so here is the real deal. Jerry was pretty much estimating, but I have weighed scads of fuel canister brands of “4 oz.” and “8 oz.” sizes. I am pretty anal about accuracy, and I weigh everything in grams, then convert the average to ounces. The following is a list of the average weights of my favorite canister brands.

110 gm (3.88 oz) canisters – full weights (with the plastic caps on); completely empty weights:

MSR IsoPro – 7.5 oz; 3.6 oz

Snow Peak Giga – 7.5 oz; 3.6 oz

100 gm (3.53 oz) canisters ( due to the higher percentage of propane, which raises the internal vapor pressure, they contain ~10% less fuel in order to be safely compliant with DOT regulations)

Jetboil – 7.0 oz; 3.6 oz

Olicamp – 7.0 oz; 3.6 oz

“220 gm” canisters:

MSR IsoPro (claimed fuel weight 227 gm) – full 13.4 oz; empty 5.3 oz

Jetboil (claimed fuel weight 230 gm) – full 13.4 oz; empty 5.3 oz

Olicamp (claimed fuel weight 230 gm) – full 13.4 oz; empty 5.3 oz

(I’m not sure how JB and Olicamp can actually put a few MORE grams of the 25% propane/75% isobutane into the larger canisters. Maybe they’re inherently stronger than the smaller ones?)

Note that the empty canisters of each brand are the same weights. I am sure that this is due to the fact that the same South Korean factory makes the canisters and fills them with the appropriate fuel mixture specified by the various brands. All of the canisters of each size appear identical, right down to the plastic caps. The only ones that look a bit different are those of MSR. The dimensions and shape are the same as those of the other brands, but it looks like the bottom concavity has been plated with some sort of silver metal (for a unique cool factor?

But yeah, the good old days are behind us. When Snow Peak made their own canisters in Japan and filled them there, the empty 110 gm canisters were 1/2 oz lighter. Likewise with MSR. Whereas their original “4 oz” canisters were much heavier than now, due to the wide base, their empty “8 oz” canisters weighed just 4.7 oz (0.6 oz lighter than the current ones). About 10 years ago the golden age ended, and everything is now done in South Korea.  Primus and CampingGaz canisters were made & filled in France 10 years ago, but I see that now Primus uses a South Korean company as well. I know nothing about what CampingGas is doing. I don’t even see their products in the States now.

p.s. – Note that MSR’s canisters have a sort of gauge to let you know approximately how much fuel remains. Cute idea, but I’ve not checked it out for accuracy.

[Bob Moulder]

From a couple of years ago, make a scale with your trekking pole.  ;^)

If you boil the same amount of water each time, the easiest way long-term is to get an accurate scale, do a few test boils and weigh the canister after each boil to see how many grams you’re using per boil.

Figure about 5 grams for 2 cups, 7.5g for 3 cups and 10g for 4 cups for a reasonably efficient system, with the flame setting of the stove roughly 2/3 of maximum. A lower flame setting is nearly always more fuel efficient than full blast… very few exceptions.

[David Thomas]

Gary’s data may be all you need.  But. . .

Another approach is to weigh your canisters (my MO is to weigh them without the cap) when you buy them or any around the house you haven’t used yet.  Then write the full weight on the bottom in Sharpie.  Not only does this let you quickly check how much you’ve used (and therefore how much you have left), but if you save the canisters and ever take up refilling them from cheaper-per-ounce 16-ounce / 450-gram canisters, you’ve got your endpoint weight already marked.  This also addresses any differences between your scale and Gary’s, but modern digital scales all seem to be pretty accurate and consistent, IME.  If you’re using an analog scale, then I’d recommend you keep your own weights, or at least confirm that your weighings match Gary’s.

Bonus tip: Get in the practice, now, of weighing your canister’s before and after each trip.  Write down the info, maybe on tape on the canister, “380 grams full” then “3-night trip, 232 grams” and then “overnight trip 170 grams” (at which point, you’ve only got 20 grams till its empty weight of 150 grams).  Pull the tape off and put it in your notebook, or gear box so you can discern what your usage patterns are.  Adding notes like “one cold dinner” or “winter camping – lots of snow melting” etc, will add value as you learn to estimate your fuel usage in advance.

Ideally, you get to a point where on the last morning of your trip, you have the option of an extra cup of hot tea, thereby burning off the last of your butane as you pack up to head out.

Also, start shaking your canisters to hear the butane slosh around inside and feel the momentum of the liquid bouncing off each side of the canister.  It’s subtle, but over time you’ve develop a feel for it and that let’s you adjust mid-trip (“opps, using a bit too much fuel, one less hot drink a day so I can be sure of reconstituting the F-D food” or “Got extra fuel!  Woo-hoo!, I’m taking a hot shower this evening!”).

Off-topic: Next GGG, let’s have a beginner competition: 40%, 50%, 60%, 70% full canisters to be arranged in order for a prize (the 70% canister?).  Points for accuracy first, ties decided by speed.  And an advanced competition: Several canisters, say 14%, 46% and 72% (known only to the judges) to estimated by the contestant, winner has the lowest total error and wins a refilling valve.

[James Marco]

There is a heck of a lot more to a stove than just fuel weight. I have used a butane stove for over 19 years. I never committed 100% to them because of the canister weight. But, I have used Roger’s Winter stove for two weeks with only a single 8oz canister and had fuel left over when I got home.

That said, a stove system is needed, not just a stove. A high efficiency pot that weighs about 3.25oz and has a quart capacity, a good, rather tight fitting, wind screen that extends slightly beyond half way up the pot (leaving some holes or a gap at the bottom for air,) a lid (can be foil) are parts of the whole stove em to get that type of efficiency (3 cups, twice per day for 14 days except the start and finish.) Turn off the stove immediately. Use a cozy for cooking (anything >180F will cook stuff.) Out of the wind. These all save fuel.

[Chris T]

Ok so I went to the camp store today and bought an extra 110g jetboil Iso can. I am going to weight it full with cap and mark it on the bottom so I know what it is when I take it out. (I had a gift card that was close to expiration, lol.)

Ok so my MSR 110g can is showing at 4.9 oz so that’s good. I can safely take this can out and not be worried about being stranded without coffee. I am basically a coffee addict so I easily drink 6 of Sea to Summit mug sized cups when breaking down and packing up camp. Even though it boils REALLY fast I have gone through an entire Maxwell House instant jar at home in zip lock sized portions now (after packing my bag last night for this trip this evening.) I know that’s gross. But I can drink pretty much anything that even approximates coffee. Eating cliff bars I can manage. Hiking without coffee? I shudder at the though.

[Jerry Adams]

Maxwell House instant?

Uh oh, this thread could degenerate quickly : )

I drink Nescafe Taser’s Choice instant myself, just because that’s what I’ve done in the past

You could probably make it with cold water if that’s all you had?

[Matthew / BPL]

Chris, Listen to Unky Shug.

[David Thomas]

Matthew and I are on the same page.  I was going to post a single image (below) – it’s the only instant coffee allowed in our house and the only one I use in recipes (like for chocolate cakes, tortes, gauche glaze, etc).

[Chris T]

Medaglia D’Oro is SOLID. I am a fan. But none of my stores around here carry it. I have to go to fairway or whole foods. If I remember I grab some Via packs from Starbucks. But I figure if the woods don’t care that I am pooping in the open or drinking some shady water on occasion or that I STINK (it broke 90 yesterday) they won’t care that I am drinking coffee flavored swill. Hahaha

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