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View Full Version : Sgt Rock ZIP stove review - comments



yuppie_redneck
2008-01-14, 01:50
I must say, after working on alcohol and wood stoves for years now, finding your site has been an epiphany of knowledge.

Your reviews and insights into the practical uses of equipment are usually spot on!

Regarding the zip stove:


Some Pro's you left out: The cheery ambiance of a wood flame on a cold rainy night. Or a hot one! It doesn't matter what the weather is, if there is a fire everyone will gather there. Since most alcohol stoves burn clear, you miss that.


Wood stoves can be used whenever canister stoves can. (Since weather here was dry all summer, we would have gone without fires on our scouting trips were it not for my little coffee can.)


Wood burns at any altitude, any ambient temperature a hiker would be able to survive at.


A well designed wood stove can serve as a windscreen and reflector for your alcohol stove, and allows you to reduce the alcohol you bring. (Instead of the fan on the zip I recommend a flexible drinking straw and your own hot air ;)


Who needs a flashlight when they have a lighter and a place to keep fire? Certainly you can use your flashlight less.


Weight of the zip stove is a consideration, but all a wood stove really needs is a way to contain the fire, control ventillation, and support the pot you cook with. My stove is a coffee can with a bunch of holes - to reduce ventillation I cover holes with dirt or rocks. It doesn't weigh much at all, certainly less than the alcohol and windscreen I don't have to carry because I have it along. I could drop the weight if I didn't like coffee and tea with my meals, by using a soup can and Ti cup instead of coffee can and Ti pot. I could also do without the coffee can plastic lid - but I like how it keeps everything together. Just be sure to find a can your 'pot' fits snugly inside of if you downsize. One thing though - on wet days you need to figure in a little added weight - to allow for picking up fuel and stuffing it in a baggie.



Since my wood stove serves as my wind screen, pot stand, water purification reservoir (with a baggie and sock - I don't like the iodine or chlorine taste of tablets and leaving the water out to air overnight gets rid of that), trash can (for flammables - why carry your rubbish?), and it nests to carry my pot, tinder, lighter, the aforementioned straw, lexan spork, washcloth, 6oz of HEET, hybrid super V-8 stove (optimized to work with the stove as wind screen), the single titanium tent stake I carry for pot support and pot lifter, and whatever else I can stuff into it - I just don't mind the extra couple oz of weight. I also carry less water since I can boil to purify as needed - although I use tabs or MIOX, having a way to boil reduces how much extra I have to carry 'just in case'.

If I didn't have to worry about scouts running out of fuel, and having to use my lil wood stove to heat more water than I planned for, I might not be so attached to it. Were fuel scarce, I am sure I'd just carry more alcohol. (Did you know most hand sanitizers burn great and come in little squeeze bottles already?) But then, if I didn't have the scouts my isopro stove would run on etOH and I'd have to build wood fires anyway :)


To avoid ash in your raman - put the lid on your pot (besides it boils faster that way).


To avoid soot on your pot..... why worry about it? Just secure the pot inside the woodstove. I do wipe off the loose stuff with a piece of paper - which I then use to start the next fire. (I cheat and put a daub of vaseline on it from one of those tiny little squeeze tubes, if the boys havn't needed it all for blisters.)


One last thing - I have yet to meet a male hiker with BO that smelled better than woodsmoke - NO STRETCH AT ALL.

yuppie_redneck
2008-01-15, 08:58
Sorry if this thread is misplaced, if so pls move it.

I was looking at the numbers on your turbo V-8 (posted at end of this for convenience).

I noticed something you did not mention. Your stove becomes more efficient at 18ml than any other volume of alcohol. (greater time above 175 per volume of alcohol added) beyond that you get diminishing returns.

At 6ml you get no time above 175.
Add 6 ml more you get 75s.
Add 6 ml more you get 125s longer above 175degrees.
Add 6 ml more you get 120s longer above 175 degrees.
Add yet another 6ml (total 30ml) and you only get another 80s above 175 degrees.

As such, one would do better to refuel this stove if burn times at 175 (cooking temp) greater than 5 minutes are desired. (Provided carrying a little less weight is worth the effort of refueling to you.)

Note, this also fails to take into consideration any heat that might be lost while refueling. (If you use a pipette method to refuel with a drinking straw you really don't lose any.)

If you don't know what a pipette is, just dip the straw into your fuel, put your finger on the top, place the bottom of the straw over your fuel reservoir, and remove your finger. I spill a ton less fuel doing it like this - certainly FAR more weight in fuel is saved than the cost of carrying the weight of the straw. Plus I use the straw to accelerate burn when using wood fires in my coffee can. If you worry about how much to add, crimp your drinking straw at your stove's usual fuel level. (Permanent marker comes off in alcohol.)

Temperature 6 ml (1 cap full) 12 ml (2 caps full) 18 ml (3 caps full) 24 ml (4 caps full) 30 ml (5 caps full)
150 degrees 250 sec. 255 sec. 300 sec. 320 sec. 350 sec.
175 degrees n/a 365 sec. 365 sec. 390 sec. 410 sec.
200 degrees n/a n/a 440 sec. 460 sec. 480 sec.
Max heat 150 F. 190 F. 210 F. 213 F. 213 F.
Time to max heat 250 sec. 365 sec. 510 sec. 530 sec. 550 sec.
Time above 175 degrees n/a 75 sec. 200 sec. 340 sec. 520 sec.
Avoirdupois ounces (weight) .16 ounces .32 ounces .49 ounces .65 ounces .83 ounce

*** Notes. compared to earlier tests I added 6 ml fuel which is what I use when I just heat for some drinks and foods which don't require a full boil. I also added a column for time above 175 F which is the temperature I have found most foods to actually be cooking. Also note that the temperatures for water and room temperature are about 10 degrees colder than last time, brrr.

Conclusions:

I am very happy with this new stove. Besides being smaller and lighter it also does the following:

1. It reaches the higher temperatures of the Cat using the same amounts of alcohol.

2. It maintains longer periods of heat, especially above 175 F than the Cat Stove which means more actual cooking time than the cat.

3. It is more efficient as well as lighter than the soda can stove.

yuppie_redneck
2008-01-15, 09:15
I really like your stove comparison chart, and I agree with you that most cooking is not done at a boil - but around 175F.

If you were to use that neat thermocouple on those stoves again with differing volumes of alcohol you could probably figure out what the most efficient volume of alcohol would be to maximize burn time at 175F like you did with your turbo V-8.

In addition, it would be fairly easy to determine how much alcohol would be needed to cook an average meal in each stove at 175F. Time boiling is useless to me unless I need to purify water due to a bonehead error. Time cooking is more helpful :)

Alcohol stoves become much less efficient at higher temperatures. My gut feeling is that your Turbo V-8 would really shine in a real world comparison like this. Before I found your site, I was already making the V-8 stoves - heating enough water to make meals on just over half an oz of 95% isopropyl*. I hadn't used fiberglass though - went organic with a shredded cotton ball (Get less itchies making the stove that way.) I also omitted the wire cloth - I use a coffee can for windscreen, wood stove, pot stand and storage. Mainly because it fits nicely over my Snow peak pot. If I were really wanting to drop some weight I would probably go to a chicken or tuna can and use one of the larger snow peak mugs with folding handle (single wall - why insulate the food from the heat if you are using it to cook by using an insulated mug?). I suppose I could also use a Heini can for a pot - but it'd be too much of a pain to explain to the scout's parents every time they saw it.



*how many ml in an oz ?
One ounce is equal to 29.57353 milliliters

SGT Rock
2008-01-15, 23:22
I'm just getting back so I'm a little cloudy headed right now. But you are right on a wood stove. Last night (and again this morning) I didn't use an alcohol stove at all. I used my campfire with a few well placed rocks in the fire ring. With that sort of set up (or a ZZip) you can keep on heating water. I made tea, dinner, mo' tea, and then heated water for "warm" water in the water bottle, then finally put a pot on next to the fire when I went to bed - the warmth from the coals kept that water from freezing overnight while the water in my bag was frozen over.


Welcome to stove addiction.