Feb 25, 2011 at 2:41 pm #1269719
I got off work early today, so I had time to experiment with some new and old stove designs with my 10 cm Imusa mug (~650 mL). After using up a whole bottle of HEET I am wondering how my results compare to others. I am specifically interested in mug type pots, around 500-700 mL size, as that is what I seem to be gravitating towards.
My fastest kitchen top burn for 16 oz of cold tap water with my IMUSA mug is 5:27, using a MBD magic mouse stove and a steel can windscreen and lid.
So what are you mug pot lovers using for alcohol stoves and how fast do they boil? I am curious about your boil time, and then, secondarily, about the setup and how much it weighs.Feb 25, 2011 at 3:54 pm #1701609
Same mug with 16 ounces of cold tap water. For indoor use, no windscreen. For outdoor use, the aluminum windscreen weighs 8 grams. The burner is a home made low-pressure sideburner that weighs 20 grams. Conveniently, that adds up to about one ounce. Boil in 4 minutes flat.
However, this has lost out to a butane stove. Butane with fuel will win, weight-wise, within three days of use. It has also lost out to an Esbit burner. The only reason I don't use Esbit much is because of the residue problem.
–B.G.–Feb 25, 2011 at 5:28 pm #1701640
@retiredjerryLocale: Oregon and Washington
What is the temperature difference from start to "boil"?
What is the weight of alcohol used?
I have some homemade stove that weighs 0.5 ounces, requires 0.5 ounces to heat 16 ounces of water 80 degrees C.
I don't care about time all that much.
But that's just what's important to me.Feb 25, 2011 at 5:45 pm #1701645
What is your "break even weight" you're figuring for your alcohol/canister comparison?
How much fuel weight (per day, per boil, or otherwise) are you figuring into that?
I've never looked that far into canister stoves, but with my whole alky burner setup using less than a half fl. oz. of fuel to boil 2 cups, and weighing almost nothing (tea light stove, the only thing that has a non-negligible weight is the conical windscreen) I'd imagine it would take me a good deal longer than 3 days to rationalize a canister for weight reasons.
That being said, my humble little tea light has no place in a speed boiling contest…7-9 minutes, depending on which pot I use. Generally I just find other things to do in that time.Feb 25, 2011 at 5:51 pm #1701648
I could be wrong, but from what I understand Travis was simply after a "time to boil", not comparing all of the possible ways to heat water with all fuel/pot/stove combinations known to man nor philosophical arguments for or against…
FrancoFeb 25, 2011 at 6:33 pm #1701669
For the alcohol stove with windscreen, it is about 1 ounce. The fuel bottle for it is another 1 ounce. Then add alcohol. I burn a lot, and I figure on 2.5 ounces per day. For three days, that is 9.5 ounces.
For butane, it is 1.65 ounces for the burner, plus 0.25 ounces for the windscreen, or 1.9 ounces total. No fuel bottle. One 4-ounce canister weighs 7 ounces. That is 8.9 ounces in all, which slightly beats the alcohol solution.
If you cook a different amount, you will easily get different results.
–B.G.–Feb 25, 2011 at 8:09 pm #1701716
I figured the difference was probably mostly in the fuel usage. Since I use around an ounce a day if I'm having 2 hot meals (less obviously if only 1 hot) my break even point is much further down the road…Feb 26, 2011 at 3:53 am #1701758
@jamesdmarcoLocale: Finger Lakes
Yeah. This can vary a lot from person to person.
Mostly I use a small, 1/2oz stove and foil wind screen. For a cone to be effective it would need really high efficiency…about 1oz combo weight is correct.
For alky, I use a lighter water bottle, this weighs 1/2oz.
I use about 1.5fluid oz per day at about a .8 density. For 3 nights this is ~5oz. Accounting for the .8 density, it actually weighs 4oz. (from http://www.simetric.co.uk/si_liquids.htm, note that in calculating density against a standard, water, you can pull a proportion and simply ignore the units. Methyl Alcohol is listed as 786.51g/l water is 1000g/l. The units "cancel" for 78.651%…rounding gives 80% or .8. Ethyl alcohol falls in the same range.)
This is 2 cups of coffee in the morning, cold lunch, 2 cups of cocoa and cooked supper at night (spanish rice, Alfredo Noodles, macarroni, etc.)
This is 5.5oz total for three days. With a grease pot and foil lid(2.75oz), total cooking setup is about 8.25oz. This beats yor butane figures AND includes a cook pot.
Anyway, the point is that we can go on all day with people stating lower and lower weights. It is really unimportant to the issue: "Fastest alcohol boil with a mug type pot"
The same set up takes a while to burn and doesn't matter to this point.
I tried several types of alcohol burners, the best was 3'42" for 8oz in an aluminum mug starting at 40F. Faster means too much heat lost and low efficiency. Slower means higher efficiency, but slower boiling times. Around .3 fl oz of alcohol used in a small white box burner Wrapped in aluminum foil, 'cept for air vents.Feb 27, 2011 at 5:11 pm #1702395
I thank everybody for the insightful comments, but Franco is right, I am mostly interested in how fast people have been able to boil water with a mug pot. I have already calculated for myself how relatively efficient multiple pot and alky stove combinations are on fuel usage and how many ounces of fuel i need to carry for a given number of meals.
My question really stems from the fact that with a supercat stove and multiple pots with wide bases, I can consistently get boil times under 5 minutes (some approaching 4) at home and nearly that fast on the trail. But since i am interested in switching to a mug pot this summer I was just wondering what type of stove everyone is using for these pots.
I have found for larger pots that sideburners are the best, they heat fast, are relatively efficiently, are ok in the wind, and don't require a pot stand. Should I be trying to use a smaller sideburner for the mug type pot or switch to something else? I have found that even though fast boils aren't always the most effiecient, as soon as it is windy the slower stoves almost never stay efficient and they take forever.Feb 27, 2011 at 6:46 pm #1702430
Travis, my alcohol plan is that I use a side-burner when I have a slightly broader cook pot like an old boy scout pot. I use a top-burner when I have a slightly narrower cook pot, like a mug. Currently, my fast boiler is a tiny aluminum teakettle that has a capacity of about 16 ounces, but it is intended only for water boiling and not for cooking.
Efficiency and speed and some other factors are all intermixed. If the burner is going so slow as to try to be ultra-efficient, then it will lose a lot of heat that never gets into the water. If the burner is going so fast as to try to get the fastest boil time, then it still can lose a lot of heat that never gets into the water. In order to find the sweet spot, you really need to make ten or twenty runs, and eventually you will find that point where speed and efficiency intersect. But then, that will be correct for only one amount of water, and if you double or halve the water, there is a completely different intersect point. Then if you change your windscreen by 20% on a windy day, there is a completely different solution. There is no simple answer.
–B.G.–Feb 28, 2011 at 11:22 am #1702663
I have been playing with the cat can and mug set up as well using a 600ml GSI mug. It seems fewer holes works better on the small mug, two rows of 11 close to the top is working consistent right now. I would like to lower the bottom set of holes some so it primes faster (about a minute right now).
I think the windscreen is more important for performance in the field, raising the stove some works better yet (more air volume? or less heat loss to ground?), the balance of air intake and a tight windscreen make the most difference to performance.
I have been using water from the fridge and leaving the alcohol outside to simulate field conditions and doing the tests on the patio (cold). Time to "hot" is about 7 minutes, full boil 8:30 using .75 ounce SLX denatured alcohol. I have been using a section of dryer vent for the windscreen, not as light as foil but more durable and it is the right diameter.
It is nice to put the stove, screen, plastic bowl (16oz Nalgene), and 3 ounce fuel bottle in the mug, very compact.
My goal is just that it works consistent, if the water is hot enough (not boiling) for coffee by the time I have got my bear bag down, and ate a breakfast bar then that is fast enough for me.
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