View Full Version : Cook System Battle
UCONNMike
03-02-2005, 22:44
I was ready to use my homemade Mountain Dew Can stove for my upcoming trhu-hike up until a few days ago, when i recieved a gear sponsorship from jet boil to use and test their product. I was excited but concerned that i was now adding too much weigh to my pack, but i dont leave this kinda problem up to assumption. So i went to the scale and had all items weighed to match the difference. these were my results.
Soda Can System:
Moutain Dew Can Stove - .35 oz
Titanium Trek 700 Pot - 4.8 oz
Windscreen - 1 oz
11oz MSR Fuel Bottle - 2.8 oz
11 fl oz of Denatured Alcohol - 11.4675 avoirdupois (weight) oz
total = 20.4175 oz at full fuel capacity
Jetboil Cook System:
total = 15 oz at full fuel capacity
so the difference is 5.4175 oz in favor of teh jetboil cook system. The Jetboil system has the cookpot, stove, fuel, windscreen in an all in one package, and is clearly superior in terms of efficency and weight.
These results were shocking to me, since i thought the soda can system was the lightest possible way to go, but now i relize how great of an opportunity it is to be part of the Jetboil Team.
Very interesting and worth a further look. I noticed on their website the listed weight is 15 oz. but they made no mention of the fuel being full as you have. Can you find where that is listed or is this based on your personal tests?
Mountain Dew
03-02-2005, 23:23
You are forgetting that it is also much easier to find denatured ora replacement fuel than it is a fuel canister for the jet boil system. Oh, and if you use a soda bottle instead of the msr fuel bottle you will save weight as well.
cutman11
03-02-2005, 23:30
And the 11 fluid oz of alcohol weighs 8.8oz, so the alky set up would be 4oz less than you have listed, bringing it within one oz of the jetboil. I dont know the jetboil system, how much fuel would it carry....you need to compare systems in terms of pints of water boiled also to be comparing equivalently.
SGT Rock
03-02-2005, 23:54
Check the weight on that JetBoil, all the reviews I have seen tested the weight with fuel bottle, cup, lid, flux ring, stove, etc at about 22.2 ounces.
Also... you need to loose the MSR fuel bottle. The bottle is made from aluminum and there is a warning that you will corrode the bottle storing alcohol in it. Switch to a plastic 12 ounce soda bottle at about 0.9 ounces.
Also, Also... 1.0 ounces for a windscreen is a little much, it should be about 0.5-0.7 ounces.
Also, Also, Also... Fuel weight for alcohol is incorrect, alcohol weighs 0.79 ounces per fluid ounce, so a 12 ounce bottle of fuel is 9.48 ounce without the bottle.
Also, Also, Also, Also... You are only looking at start weight which is misleading. If you carry your stove with the mods I mentioned, it will have a start weight of about 5.75 + 9.48 = 15.23 ounces,and the average weight between re-supply will be 5.75 + 4.74 = 10.49 ounces. The JetBoil will have a start weight of 22.2 ounces with an average weight between re-supply of 20.64 ounces.
UCONNMike
03-02-2005, 23:57
the alcohol doesnt weigh 8.8oz, it is more dense than water, and that caluclation of 11 oz of denatured alcohol was doen using the weight of water. plus you can use any brand of cannister fuel with a jetboil, and since i have a gear testing sponsorship they are providing fuel drops for me along the way. and i understand i could jsut use a soda bottle, but i know myself, and I'd prob end up drinking out of it by accident, cause i'm a huge idoit. Once they send me the stove i will weight it at teh post office. But the point i was trying to make is that the difference in weight isnt really all that great, and in my own opinion the jetboil is a superoir product to that of a soda can stove.
UCONNMike
03-02-2005, 23:58
the guy i got my weighs from must have screwed up, oh well....my bad
SGT Rock
03-03-2005, 00:14
the alcohol doesnt weigh 8.8oz, it is more dense than water, and that caluclation of 11 oz of denatured alcohol was doen using the weight of water. plus you can use any brand of cannister fuel with a jetboil, and since i have a gear testing sponsorship they are providing fuel drops for me along the way. and i understand i could jsut use a soda bottle, but i know myself, and I'd prob end up drinking out of it by accident, cause i'm a huge idoit. Once they send me the stove i will weight it at teh post office. But the point i was trying to make is that the difference in weight isnt really all that great, and in my own opinion the jetboil is a superoir product to that of a soda can stove.
Negative good buddy: http://www.csgnetwork.com/specificgravliqtable.html
Water has a specific gravity of 1, alcohol has a specific gravity of .785, so alcohol weighs less than water.
the alcohol doesnt weigh 8.8oz, it is more dense than water, and that caluclation of 11 oz of denatured alcohol was doen using the weight of water. The specific gravity for denatured alcohol is 0.79.
Spec Grav= (Dens of Material)/(dens of H2O)
therefore the density of alcohol would be 79% of H2O. So, the weight of the alcohol would be less than that of water. If the weight of 8.8 fluid oz of H2O was 11 oz then the weight of 8.8 fluid oz of alcohol would be 0.79*11oz=8.69oz. So alcohol's weight is roughly equal to the number of fluid ounces.
And I have verified this by actually weighing my alcohol.
SGT Rock
03-03-2005, 00:24
Except that water weighs more than 1 ounce per fluid ounce. An 12 ounce bottle of water weighs 12.48 ounces, and an 12 ounce bottle of alcohol would weigh 9.85 ounces, I was off by .37 ounces on my earlier post, my bad.
Except that water weighs more than 1 ounce per fluid ounce. An 12 ounce bottle of water weighs 12.48 ounces, and an 12 ounce bottle of alcohol would weigh 9.85 ounces, I was off by .37 ounces on my earlier post, my bad. Maybe I need to reweigh my alcohol. hmmmm.
Okay I just reweighed my alcohol. 0.5 fluid ounces weighs in at 0.45 oz.
Therefore You can use the fluid ounce to weight ratio of 90%. Meaning you take your volume and multiply by 0.9 to get your weight.
SGT Rock
03-03-2005, 00:36
It can be confusing, When calculating pack weight, water weighs 1.04 ounces (roughly) per ounce, so if you carry two quarts (32 fluid ounces) it weighs 33.28 ounces. And if you packed the same amount of alcohol (pure) it would weigh 26.29 ounces. So if you like 80 proof whiskey, then it would be about (33.28*.6)+(26.29*.4) to get the real weight of 19.97 + 10.52 = 30.49 ounces. This isn't exact, but close. It is all in my spread sheet :sun
SGT Rock
03-03-2005, 00:41
Okay I just reweighed my alcohol. 0.5 fluid ounces weighs in at 0.45 oz.
Therefore You can use the fluid ounce to weight ratio of 90%. Meaning you take your volume and multiply by 0.9 to get your weight.
Actually your scale isn't accurate enough, the actual calculation as memory now comes to me is roughly 0.82 ounces per fluid ounce. Since water is 1.04 x alcohol 0.79 specific gravity, you get the calculation.
cutman11
03-03-2005, 00:52
So after all that matematical stuff, taking Sgt Rock's info, I stated 11 oz would weigh 8.8 oz, but actually would be 9.03 oz, so I was .23 oz low on my estimate of the weight. Hope you use a scale that weighs to the 2nd decimal place if you need this kind of accuracy. How much will the dirt on your pack weigh after you hike with the jetboil vs. the alky stove?:-?
Okay,
the density of water is 1gm/cc
There are 0.034 Fluid ounces in 1 cc.
So if we multiply the volume of water by its density we obtain its mass then we multiply by the acceleration due to gravity and we get its weight. Therefore,
32oz./(0.034oz/1cc)*1gm/cc*9.8m/s^2=9223.5gm*m/s^2=9.22kg*m/s^2
=9.22N
1lbf=4.45N
9.22N/(4.45N/1lbf)=2.07lbf
16oz=1lbf
2.07lbf/(1lbf/16oz)=33.12oz
this is how much 32 fluid ounces of water weighs
to find the weight of alcohol
0.79*33.12oz=26.1 oz of alcohol
This is 81% of the volume.
Which is interesting since when I weighed it out I got 90%. The reason there is the descrepency is because using the calculations above one assumes STP (standard temperature and pressure). STP is 0C @ 1ATM. Now how likely is it that one will encounter this on an everyday basis. Pretty unlikely. Since I am at a higher elevation than most (4500ft). I would say one should probably use 85% of volume is weight for alcohol. Yes I realize that is a strange statement.
SGT Rock
03-03-2005, 00:57
...plus you can use any brand of cannister fuel with a jetboil, and since i have a gear testing sponsorship they are providing fuel drops for me along the way. and i understand i could jsut use a soda bottle, but i know myself, and I'd prob end up drinking out of it by accident, cause i'm a huge idoit. Once they send me the stove i will weight it at teh post office. But the point i was trying to make is that the difference in weight isnt really all that great, and in my own opinion the jetboil is a superoir product to that of a soda can stove.
Well you did get a sweet deal with a stove and free canisters, I don't blame you one bit for taking the deal ;)
But, just remember that their canister is also a little smaller in fuel capacity to some of the other models, so if you use an MSR fuel canister it will be an even heavier base and average weight than with the JetBoil brand. :datz
As to superior product, I really don't consider a MtDew can stove a product, so the JetBoil is a product, but the can is a improvised solution :D
UCONNMIKE
you forgot to add that the jetboil has a cozy also...It makes the heat retention very impressive...
SGT Rock
03-03-2005, 07:44
UCONNMIKE
you forgot to add that the jetboil has a cozy also...It makes the heat retention very impressive...
That is a good point, I was thinking the same thing earlier. You can add a good cozy for 0.9 - 1.2 ounces. And since the JetBoil has a built in igniter, you should also add a lighter into your calculations at 0.6 ounces for a Scripto. This would bring the MtDew stove to a base weight of 17.39 with an average weight between re-supply of 7.55+4.92 = 12.44 ounces (note: correct calculation for fuel weight).
But I also had another thought - fuel usage. A 4 ounce canister is about equal to 8 fluid ounces of alcohol. Since the JetBoil canister is actually about 3.2 if I remember correctly but is also slightly more fuel efficient than a regular sove - you are comparing ~1.5 times the required fuel for the same section compared to the JetBoil stove. So for a realistic comparison you should compare about 9 ounces (this gives you a 10% fudge factor on comparison) so a start weight of 7.55 + 7.38 = 14.93 ounces, and an average weight between re-supply of 7.55 + 3.69 = 11.24 ounces, about half that of the JetBoil.
It can be confusing
...
So if you like 80 proof whiskey, then it would be about (33.28*.6)+(26.29*.4) to get the real weight of 19.97 + 10.52 = 30.49 ounces. This isn't exact, but close. :sun
Good Grief! The math...! The calculations...! Now, I *NEED* the whiskey!
RE: JetBoil system -- Did I read that this thing is kinda "top heavy" and perhaps prone to tipping over too easily? And, that "per the mfgr's specs" you should only put 2 cups of water in the .7 liter pot?
hopefulhiker
03-03-2005, 08:20
One problem with the Jetboil is is weighs 15 oz without the fuel.. An idea I had was to use an down hood off and old down jacket as a cozy and as a sleeping hood.
MileMonster
03-03-2005, 08:59
Nice that you got to be a tester. The fact that they are shipping fuel canisters is way cool. Those things cost some coin to ship legally.
Your statement that the jetboil is "clearly superior in terms of efficency and weight" is pretty bold.
SGT Rock
03-03-2005, 09:07
Your statement that the jetboil is "clearly superior in terms of efficency and weight" is pretty bold.
Good point. Let me also say as a person that has tested gear for a lot of people and also as someone that has asked people to test my stuff - be VERY objective. Just because they gave you a stove doesn't mean you have to love everything about it or sing hosannas while on the trail. Weigh it, drop it, get it dirty and try to use it. See how far you can take it apart and then how easy it is to put back together. Pick it apart, see what you as a backpacker want from it and where it does or does not meet your expectations. I suspect that the reason JetBoil got involved with Jack is they know he is brutally honest.
In the end, tell people honestly what it's deficiencies are and what it's positives are, tell what it functions are really like. Remember that gear selection is based on a lot of choices about things - just saying it is clearly better or "THE BEST" doesn't really hack it when folks want info before buying. Subjective information helps people to decide based on personal preference criteria.
superman
03-03-2005, 09:22
All gear is a consumable to me and not to fall in love with any of it. What works best on one hike may not be right for the next hike. I had a good idea that each piece of gear that I aquired would be better than what I had. I may have ten different stoves of different types. Each one was going to be "the answer." I tend to take my open weener can/esbit frame stove. On some short hikes I've taken my old zip stove. I'm not fond of canisters. I don't like stoves I have to fiddle with. Simple, ease of use and light weight works for me but next hike ....well who knows.
bulldog49
03-03-2005, 09:28
Those things cost some coin to ship legally.
Not true. They can be shipped USPS ground at no additional cost. I buy fuel from REI, its shipped at the regular shipping rate.
flyfisher
03-04-2005, 08:24
........
These results were shocking to me, since i thought the soda can system was the lightest possible way to go, but now i relize how great of an opportunity it is to be part of the Jetboil Team.
Not nearly the lightest. Here is one that costs under $20:
Cookkit contents:
3 cup AntiGravity pot with lid, CoffeeStove, pothandle,
firestarter, lighter, matches, pot cozy, spoon, silnylon stuff sack.
weight: 10.5 oz (297 g)
CoffeStove:
http://www.imrisk.com/woodgas/coffeestove.htm
(weight of the stove is 3.0 oz) - cost $0
Time to build - an hour or so
Fire starter is 3 dozen 1 in x 3/4 in squares of cardboard soaked in candle wax
No fuel cannister, no other fuel weight.
***************
I also had the opportunity to learn how to start a fire even when it was wet outside.
SGT Rock
03-04-2005, 09:02
Basically a Hobo stove. Have you thought about adding a small 6v case fan to that?
Another alternative to that sort of stove is the Nimbilwill Nomad stove.
Actually your scale isn't accurate enough, the actual calculation as memory now comes to me is roughly 0.82 ounces per fluid ounce. Since water is 1.04 x alcohol 0.79 specific gravity, you get the calculation. I kinda already explain the descrepency in the measurements and the physics, but I wanted to mention that my scale is damn accurate. It is a digital scal that measures down to 1/100th of an oz.
SGT Rock
03-04-2005, 14:43
LOL, good enough for me ;)
Dances with Mice
03-04-2005, 15:01
I kinda already explain the descrepency in the measurements and the physics, but I wanted to mention that my scale is damn accurate. It is a digital scal that measures down to 1/100th of an oz.
That doesn't mean it's damn accurate. It just means it's damn precise. Two different things. That doesn't mean I think it's inaccurate, I'm just saying...
flyfisher
03-04-2005, 16:14
Basically a Hobo stove. Have you thought about adding a small 6v case fan to that?
Another alternative to that sort of stove is the Nimbilwill Nomad stove.
Yep, I sure have Sarge. About 5 designs worth. Some of them, out on my web pages work very well. However, by choosing the dimensions of the Coffee Stove carefully and experimenting both sides of it, I was able to find a very efficient size that stays hot, because of reflections and draws enough air to burn efficiently.
Other twig stoves:
see the five designs at:
http://www.imrisk.com/forge/forge.htm
which use fans. However,
I do like not having to depend on the battery.
And a down draft wood gas stove here:
http://www.imrisk.com/woodgas/ddstove.htm
That doesn't mean it's damn accurate. It just means it's damn precise. Two different things. That doesn't mean I think it's inaccurate, I'm just saying... I know the fact that it measures down to 1/100th of an oz does not make it accurate just precise,. What I meant to say after that was that it is used in science labs at the University where I work, but apparently I didn't say that.
Anyway this is not even on subject so... The original point was that the Jet Boil after a few days is not as light as he was stating and in fact was not as light from the start.
Dances with Mice
03-04-2005, 18:40
The original point was that the Jet Boil after a few days is not as light as he was stating and in fact was not as light from the start.That is both accurate and precise.
That is both accurate and precise. lol lol lol