I Want a Carry Weight Ethanol vs Canister Sanity Check (cause I’m being dense)

Eat the cat food.  Since it is a consumable, it does not count in your base weight.

Do you remember this video on how to bake tuna in a can?

Alkie stoves . . .
A friend of mine and a long-term member of BPL went walking with his wife one weekend. He planned to cook dinner for the two of them on an alkie stove. When he got to the campsite and unpacked, he found the bottle of metho but not the stove. Um … Er … Oh Dear …

His wife kicked an old Coke can (litter) at him and asked if it was any use. 10 minutes later, with the help of his folding pocket knife, he was all set up.

Cheers

Well, I did a LOT of research into this with a couple dozen different stoves. Here is what I came up with. (I had a lab available about 20 years ago._)
5-6gm for canister fuel for 500ml from 5C in lab
12-15gm Ever Clear from 5C in lab (about 1/2oz)
17-20gm Yellow HEET from 5C in lab (about 5/8oz)

A 100-110gm canister weighs about 100gm (roughly 100% of fuel weight is the can, about 75% of fuel weight is the can for 220gm canisters.)
Bottles for carrying WG or Alcohol are about 30gm up to about a liter.

Alcohol (switching back to ounces.)
Counting stove and fuel only about 3.0oz is needed for one night boiling 2 cups for supper and 2 for breakfast. (I need three cups at every meal or roughly 3.5oz in the field.) 7 nights is around 12.0oz, discounting the differences in alcohol.
Canister
Counting stove and can, around 10.25oz is needed for one night. 7nights is about 10.25oz. There is a step function per can.

Least carry weight for 7 nights is Canisters.
(WG and canister fuel have roughly the same heat value.)
For short trips up to 4-5 nights alky is lightest.

Note that I have a good breakfast of oatmeal and 2 cups of coffee. For supper I need 2 cups and I have a cup of cocoa. Depending on your usage, it could be more or less.

Since I only boil once a day (1-2 cups of water) alcohol always came out lighter for me.  Canister would eventually overtake it, but probably not before I would have to resupply for food.  I’ve carried 14 days worth before and probably don’t want to carry any more than that!

Yeah, different strokes. I don’t resupply for about 14 days, usually. At about 30oz of water boiled twice per day, an 8oz(220gm) canister will do me for a couple weeks. I have been out for a month at a time when I was working on lean-to’s. The old SVEA is ultra reliable for this. If I was to use alky for this, I would go through about 42oz for 28 days and 21oz for 14 days. A single canister only weighs about 13oz for two weeks, 26oz for a month.

Do we need to send up some Spam so his cat has something to eat?

And it’s a wrap. At least until I get some time with this setup. I finished making a Caldera-cone like screen that fits my supposed requirements for compactness, ran some burn checks through it and… came up with what everyone else gets for burn times and fuel consumption. The end goal was pretty efficient both in fuel and packability. That was successful. It was also a very good intellectual exercise. I’m a firm believer we need to exercise our brains as much as our body. In that sense, this was not a waste of time. I had the concepts but not the math, so online triangle solutions, cone solutions (a 360 deg triangle), arc and cord calculations to make the pattern. My recommendation though? Just buy a Caldera Cone and be done with it. Part of what turned me away was their stating something about it is optimized for particular stove and I just went south from there thinking it’s not going to work for me.

I do want to throw out another huge thank you to our Bushcraft / BPL communities and MJGEGB for sending me the stoves. They are awesome.

Here’s the gist of what I learned: A truncated cone is called a Frustum. Large Ti cup seems more efficient than smaller Ti cup, probably more heat bypasses the small cup. No matter how you slice it, cones are a PITA for packing. Alcohol stoves that have wicking material and a cap and don’t spill are a blessing. The slot for the cup handles open up at the bottom when formed into a cone. Ooops. On a two-part cone the bottom section gets compressed by the top section and disengages, requiring something extra to keep it together. I used paper binder thingies. Darn, that’s small pieces that can be lost. No special tools: drill, tin snips, pokey thing, rulers, wire, marker pen, cardboard, large sheets of paper.

Half a dozen burn tests and I averaged 6.2 grams ethanol per cup, or 26 grams per liter water rolling boil. (That’s .26 fl oz per cup and 1.11 fl oz per liter if my math is right) in ideal circumstances and 60 deg water. Good enough.

When I pack it, the two part cone rolled up fits inside my 700 ml Ti cup with just a little under an inch sticking out. Pretty compact. Missed my target by “this much.”

Nice job on the cone. Don’t light that on your portable table, you’ll probably melt a hole in it.

I discovered after some sloppy at-home tests as well as field experience that I can get 16-18 “boils” of a 500 ml pot from a canister, and at the rate of 2 1/2 to 3 boils a day, the canister with a BRS stove is more weight efficient than Esbits after only several days, not to mention much more enjoyable to use. For longer trips, the larger canisters are even more efficient. I believe that alcohol is even less efficient than Esbit, although I have tested it extensively.

I’ve backpacked the Grand Canyon twice using ESBIT. It is quite efficient when used with a Caldera Cone and mating pot. And I much prefer it to alcohol for several reasons. I do actually cook with ESBIT with no problems.

Nice job, Eugene! Yeah, almost all alcohol burners are very close in fuel consumption. About 0.6oz/2cups will cover most situations (except very cold.) I use a 1oz/burn (3 cups) to insure things will boil. IFF you use filtered/treated water, about .3oz/cup is good, or, around half normal consumption.

Thanks folks!  I did an outside burn today in 6 – 12 mph gusts, on a hill, and came up with the same (i.e. very close) 28 grams fuel / 1 liter 60 deg water, fuel consumption rate, and 59 deg ambient temps.

Eugene, Looks good. That’s about the same as I get. But, I start at a lower temp (34F, or ice water.) Very Cold starts at 20F.