tomas
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Post by tomas on Apr 19, 2016 6:25:26 GMT -8
Now if it's believed that a longer time to boil means more fuel consumed then I'd understand the concern That's the issue for me. Longer burn times equals more fuel being used. For me, canister and WG stoves are more efficient and reliable. I like my Trangia, but I also feel it is more limited in what environments it works best.
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BigLoad
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Post by BigLoad on Apr 19, 2016 6:28:33 GMT -8
For some, the time matters because the stove is used in the morning and night. Coffee in the morning, maybe some oatmeal, lots of folks will use the stove twice on several days of a trek. That said, decreased boil time can mean less fuel used and less time spent. The correlation between boil time and fuel efficiency is actually weak to nonexistent. Gabby's graph isn't too different my own tests, and it shows in general that a stove that takes twice as long to reach a boil also burns for twice as long on the same amount of fuel, so a slow stove boils the same amount of water per unit fuel as a fast stove. There are efficiency differences between stoves, but they're not all that big, and the most important factors are things like pot diameter, height of the pot above the stove, and wind protection.
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Post by Coolkat on Apr 19, 2016 7:01:45 GMT -8
The correlation between boil time and fuel efficiency is actually weak to nonexistent. Without taking the time to do my own testing I've always thought this might be true.
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crawford
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Opportunity is missed by most people because it is dressed in overalls and looks like work.--Edison
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Post by crawford on Apr 19, 2016 9:23:07 GMT -8
Hence my use of the words "can mean less fuel used." Other things play into efficiency, such as diameter of the pot compared to the diameter of the burner, wind and air temp, air pressure, composition of the pot to name just a few.
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Post by charly13 on Apr 20, 2016 23:40:07 GMT -8
From the point of view of construction and function, your stove is pretty much a Trangia (-clone). Most DIY designs burn about 30ml of alcohol to boil the standard half liter of water. Some are very sensitive to ambient temperature, too, and just quit in cold weather or require lots of priming/preheating.
More efficient stoves go way below 30ml per half liter and reach 15ml or less.
I tinkered for two years to get a more fuel efficient design, here is what I use:
www.youtube.com/watch?v=9upnZX03GgM
It is a tad more fuel efficient than TD's 10-12 stove. If you want a pretty fuel efficient stove and don't like to tinker, get a 10-12. The secret is to keep the flame small and allow about 10min to boil your standard half liter of water, so you waste less heat than when you boil it in four minutes.
Happy trail cooking!
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Post by charly13 on Apr 21, 2016 0:38:32 GMT -8
The correlation between boil time and fuel efficiency is actually weak to nonexistent. Agree: the windshield and pot design are the absolutely prime concerns. Under identical conditions however, there still is quite a difference in fuel efficiency, with smaller flames and longer burn times (burning less alcohol per minute!) giving you a more fuel-efficient cooking process (I testburnt many stoves against the 10-12 under identical conditions). Also look for soot on your pot. Soot is un-burnt fuel and a sign for an inefficient burning process. This again is mostly due to a non-optimal set up like a pot too low over the flame and/or a flame too big for the setup (too little air for the fuel to burn clean).
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walkswithblackflies
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Post by walkswithblackflies on Apr 21, 2016 4:48:53 GMT -8
I just use a very simple cat can design. I like simple in the wilderness... less to break, foul, etc.
I have thought about making another, more efficient model, but I have determined I'm far too lazy.
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Post by wgiles on Apr 21, 2016 5:31:15 GMT -8
I use the Supercat and Starlyte styles with Jim Wood's Firebucket Wind Screen, but I also use commercially made stoves. I prefer the Starlyte because the fuel won't spill if I tip it over. It does take a while to boil water and its performance in wind can be very poor, but it's lightweight and nearly foolproof. For warming, I use a tea candle in the same type of gift tin that the Starlyte is made in. I use an Olicamp heat exchanger pot with the Starlyte and it cuts a minute off the boil time vs the same pot with no heat exchanger.
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BigLoad
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Post by BigLoad on Apr 21, 2016 8:57:27 GMT -8
The correlation between boil time and fuel efficiency is actually weak to nonexistent. Agree: the windshield and pot design are the absolutely prime concerns. Under identical conditions however, there still is quite a difference in fuel efficiency, with smaller flames and longer burn times (burning less alcohol per minute!) giving you a more fuel-efficient cooking process (I testburnt many stoves against the 10-12 under identical conditions). Also look for soot on your pot. Soot is un-burnt fuel and a sign for an inefficient burning process. This again is mostly due to a non-optimal set up like a pot too low over the flame and/or a flame too big for the setup (too little air for the fuel to burn clean). Burn rate has almost nothing to do with fuel efficiency, even controlling for the other factors. Burn rate is determines how fast the heat is released. Fuel efficiency is what fraction of the released heat makes it into the water, regardless of whether that release happened fast or slow. Gabby's chart has a good example of roughly the same amount of fuel required to reach boiling on two different stoves, except one of them does it twice as fast as the other. Their fuel efficiency is practically identical, although the burn rate is different by a factor of two. Fuel efficiency is measured in volume of water boiled per unit of fuel, not volume of water boiled per minute or volume of fuel burned per minute.
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Deleted
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Post by Deleted on Apr 23, 2016 17:21:17 GMT -8
I made a couple DIY stoves, ended up opting in the long run with a Trangia and a Click Stand combination. I use it all year round.
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Post by charly13 on Apr 29, 2016 1:24:48 GMT -8
Burn rate has almost nothing to do with fuel efficiency, This has to be relativized. In the setting as per chart apparently no. I suspect the "grease pot" was of rather large diameter (8in), unfortunately the chart is partly unreadable and does not specify the pot diameter. I did dozens of testboils with identical pot/windshield set ups (toaks Ti 1300, 145mm/5.5in dia and TD TiTri cone). There, burn rate would matter and a lower burn rate / longer time for boiling made a difference of 10 to 20% in alcohol consumption. I suspect (no tests yet) there is an optimum somewhere, as heating the pot with too small a flame will never get you to a boil: radiant loss will be too great. I also testboiled the TD cone for the 750ml/110mm (about 4.5in) mug "against" the 145mm/5.5in set up and found the larger dia pot having an advantage of about 10% less alcohol consumption over the mug. So, testboil your equipment. Weigh your water - measuring cups are too inexact. Measure your alcohol with a 10ml or 20ml syringe (get it cheaply at your drugstore - but don't ask for needles...). Then you will find out which setup works most efficiently for your conditions. Happy trail cooking!
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Post by aabigrick on May 3, 2016 19:49:56 GMT -8
I made several diy alcohol stoves. Then I bought a whitebox alcohol stove, and it worked way way better than anything that I had ever made.
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rebeccad
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Post by rebeccad on May 4, 2016 19:41:28 GMT -8
I made several diy alcohol stoves. Then I bought a whitebox alcohol stove, and it worked way way better than anything that I had ever made. That was pretty much my experience. But that won't necessarily stop me from messing around with other DIY stoves.
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Post by aabigrick on May 5, 2016 7:17:29 GMT -8
Yeah they are fun to make and see how they perform, I made one mtn dew can stove that got fully lite super fast and burned amazingly well actually faster than the whitebox and burned just as good but, it wasnot high enough and thus ran out of fuel to fast. I didnot make any cat can stoves that i liked, depsite several attempts.
Whitebox for the win.
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rebeccad
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Post by rebeccad on May 5, 2016 9:41:52 GMT -8
I didnot make any cat can stoves that i liked, depsite several attempts. Main thing I liked about the cat stoves is that I could make one anywhere with nothing but an awl or needle to poke holes. It wouldn't be super effective, but it would work. Nice to know there's a way to deal in an emergency, like if the airline confiscates your stove (not that that's likely with an alky stove; just another nice thing about them).
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