MELTING SNOW: Fuel Efficiency and Boil Time Comparisons of Four Gas Backpacking Stoves in Winter Conditions
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Tony Burnett
(tlbj6142) - F

Locale: OH--IO
Re: Snow melt: When and how much? on 11/16/2005 15:19:43 MST Print View

Re-reading the above article, it seems as though Dr J melts snow 3 times per day...

Mid-day: 2.5L melt no boil!
Evening: 2.5L melt and *boil*
<optional 3am re-heat?>
Morning: re-boil (should be re-heat??) 1.5L for breakfast and then melt (and boil??) another 1.5 L.

Leave camp with 2.5L.

Repeat...

Edited by tlbj6142 on 11/16/2005 16:02:11 MST.

Rick Dreher
(halfturbo) - MLife

Locale: Northernish California
Re: Snow: Boil or Treat? on 11/16/2005 15:43:18 MST Print View

Let me refine my question a bit.

All I've ever observed in my snowmelt pot has been tree debris, pollen and the occasional frozen insect (nope, not claiming microscopic vision).

I only snowcamp in seasonal snow in western U.S. mountains. Whenever possible, I gather snow for drinking water in clearings, well away from trees to minimize windblown debris. My presumption regarding my "source" snow is that there's little or no chance of it carrying disease pathogens--no viruses, bacteria, protozoa, etc. Further, visual inspection should alert me to the presence of animal or human waste in the immediate area where I'm collecting, making it relatively easy to avoid.

So, if I'm going to treat or filter my melt water, what am I targeting and how did it get there?

Don Selesky
(backslacker) - M
Re: Snow melt: When and how much? on 11/16/2005 17:47:01 MST Print View

I try to drink as much as I can before I take off in the morning carrying 2 liters. I go through the drink-as-much-as-I-can routine in the evening at camp. Don't want to carry more than 2L, but I definitely can drink that much while hiking.

William Siemens
(alaskaman) - F
snowmelting on 11/17/2005 00:36:08 MST Print View

Thanks Ryan, good info. A question occurred to me...I have read somewhere, probably here on this forum or in the print magazine, that you can save fuel by running the stove at less than full-tilt-boogie. I realized that when its really blasting, a bazillion btu's are floating up into the air...So am wondering, if you used the Xtreme at a moderate setting, not as much heat escaping arount the side of the pot, if maybe you'd end up with boil times and fuel economy more like the Jetboil? Inquiring minds want to know. Cheers, Bill

paul johnson
(pj) - F

Locale: LazyBoy in my Den - miss the forest
Re: Re: Snow: Boil or Treat? on 11/17/2005 00:44:10 MST Print View

Rick,

you make a real good point here. good thinking. i still, not very often, mind you (i try, sometimes, to act like an adult) eat "virgin" snow.

there are no pathogens, TMK (to my knowledge), that i can think of that are found in "virgin" snow. how they would get into pure "virgin" snow, i can't even imagine. if you're at all concerned, dig down a ways and you'll obviously find snow not exposed, except for while falling and a short time afterwards, to whatever else might be in the air - if anything (these aren't the types of viruses, i.e. airborne pathogens, we're normally concerned with anyways). this snow also has never been in contact with the ground or any living thing. also, not too many birds flyin' about during a snow storm, right?!

[note: BTW, HTST (hi-temp, short time) pasteurization of milk is performed at ~162deg F for ~16-20sec. this is sufficient to kill bacterial and viral enteric pathogens - acc. to the FDA. also, all "bugs" in the milk get ~5log (IIRC), reduction fr/HTST pasteurization. this is a common method of pasteurization used by dairies. i only mention this to show that, for snow at least, boiling is not necessary to obtain pure drinking water.]


i gotta' believe that it's 'ok' to eat/drink this snow/water w/o purifying. why? kids all over the world would be comin' down w/all manner of afflictions, diseases, and plagues. many of us would never have made it into adulthood with all of the snow we ate. i know, not a very scientific method, but w/so much anecdotal evidence to the contrary, how can we believe pure "virgin" snow can make one sick? just think of kids growing up for past several millenia as one giant field experiment in snow eating. our observation of the results of this experiment would be that kids can eat pure "virgin" snow w/impunity - and this snow isn't even heated to make drinking water. i think we would be safe in extrapolating these observations to adults.

as a kid growing up in 50's and early 60's, the only popular concern (prob. a mother's phobia) we heard was radioactive fallout from the "bomb" tests (in the NE, we live on the receiving end of the jet stream/prevailing winds). [i ate a lot of snow - guess that explains quite a few things...!!!]

oh...and...as mom always warned, "Don't eat the yellow snow!!".

Edited by pj on 11/17/2005 02:48:03 MST.

Bob Gabbart
(bobg) - F
Snow pathogens on 11/17/2005 06:41:52 MST Print View

On the PCT through the Sierras there is a red fungus? that grows on the snow. I know PCT hikers have gotten sick from it and I saw it myself on my JMT hike this past summer. Anyone know what that is?

Douglas Frick
(Otter) - MLife

Locale: Wyoming
Re: Snow pathogens on 11/17/2005 10:58:00 MST Print View

>red fungus? that grows on the snow.


You can Google a lot of decent info on this topic. Here's one quick reference: <http://www.straightdope.com/mailbag/mpinksnow.html>

Interesting that it's UV resistant, so my Aquastar probably wouldn't be the best solution for purifying watermelon-snow meltwater.

paul johnson
(pj) - F

Locale: LazyBoy in my Den - miss the forest
Re: Re: Snow pathogens on 11/17/2005 13:40:46 MST Print View

good info. many thanks. was thinking that it might have been an algae (snow/water + red color), but couldn't imagine how it would get there and wasn't at all sure enough to venture anything but a mental guess. go figure.

>>"Interesting that it's UV resistant, so my Aquastar probably wouldn't be the best solution for purifying watermelon-snow meltwater."

perhaps more research needs to be done. remember the UV range of the EM spectrum is divided into 3 sub-ranges, viz. UV-A, UV-B, and UV-C. both Steripen and AquaStar produce UV-C light primarily at the 254nm wavelength. also, recall that the UV-C range is the most bio-active portion of the UV range(s).

i didn't look at all of the links, but one of them speaks of UV resistance. however, the range of wavelengths cited are UV-A and UV-B. these have less of an effect than UV-C. i also don't know the level/intensity of UV-C the algae is exposed to in the Artic and on Mtns, and how this level compares to SteriPen and AquaStar levels/intensity.

i'm not saying UV-C would work, just that it may work better than UV-A and UV-B. the link had no info on UV-C. so, we are left wondering.

BTW, the cells are large enough that even a so-called "cyst" filter will remove them.

so, now our mother's should also tell us "Don't eat the pink/red snow either".


EDIT:
be sure to read Rick's later post. in it he mentions a toxin, hence filtering or any method that doesn't deal with chemicals is not a viable method. bottom line: stay away from colored snow.

Edited by pj on 11/17/2005 14:26:50 MST.

Rick Dreher
(halfturbo) - MLife

Locale: Northernish California
Re: Watermelon snow on 11/17/2005 14:00:38 MST Print View

I typically see pink snow in summertime conditions when there's usually plenty of water available directly and it can be entirely avoided. Not to say that the algae can't appear in meltwater!

On the topic, I do know folks who've ingested some of the stuff and report it gives them the runs, but nothing more dramatic. I've never seen it described as an acute health hazard.

Donning my speculation hat, the algae likely manufactures a toxin--in the manner of the famous red tide algae but not nearly as toxic. Killing the algae is probably not the goal; rather, you'd want to neutralize or remove the toxin. Perhaps carbon adsorbtion?

Best to avoid in the first place!

p.s. UV will kill algae, I've got a UV system on my koi pond to do just that.

Edited by halfturbo on 11/17/2005 14:01:40 MST.

Ryan Faulkner
(ryanf) - F

Locale: Mid atlantic, No. Cal
Re: Re: Watermelon snow on 11/17/2005 14:10:12 MST Print View

I belive the Steri Pen water purifier uses UV light to kill bacteria

paul johnson
(pj) - F

Locale: LazyBoy in my Den - miss the forest
Re: Re: Watermelon snow on 11/17/2005 14:20:27 MST Print View

Rick,

regarding your pond's UV system, do you know the wavelength and intensity/power level of the light produced?

Rick Dreher
(halfturbo) - MLife

Locale: Northernish California
Re: UV system on 11/17/2005 16:41:54 MST Print View

Hi Paul,

My pond system emitter is 25 watts and has an output range of 250-280nm. The maker doesn't give an intensity spec, but does note it's 40% efficient in generating UV (I suppose the rest goes into visible light and heat).

These units are available in many wattages and sizes to match pond size and conditions.

FWIW the UV AquaStar has a target output 254nm at 4 watts.

Frank Deland
(rambler) - M

Locale: On the AT in VA
winter stove on 11/21/2005 12:48:15 MST Print View

The Coleman is great for ease of use, no priming, but at 19F below, the flame was so low it looked like a low fuel burn. The MSRs workred like blow tourches. Glad my companions had those.

Tony Burnett
(tlbj6142) - F

Locale: OH--IO
Re: winter stove on 11/21/2005 13:54:16 MST Print View

Frank;

At -19F? Or below 19F?

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: snowmelting on 11/23/2005 02:04:50 MST Print View

> that you can save fuel by running the stove at less than full-tilt-boogie. I realized that when its really blasting, a bazillion btu's are floating up into the air...So am wondering, if you used the Xtreme at a moderate setting, not as much heat escaping arount the side of the pot, if maybe you'd end up with boil times and fuel economy more like the Jetboil?

Yep. Moderate power, windshield, lid: I quite literally halved my fuel consumption.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: winter stove on 11/23/2005 02:07:23 MST Print View

> The Coleman is great for ease of use, no priming, but at 19F below, the flame was so low it looked like a low fuel burn. The MSRs workred like blow tourches. Glad my companions had those.

Well, -19 F is a shade cool...
But no problem: just move the Powermax cartridge around so it gets a bit of radiation from the stove to warm it up. And insulate it from the snow of course.
As long as you can touch the cartridge (pain thereshold about 40 C) it is NOT too warm.

paul johnson
(pj) - F

Locale: LazyBoy in my Den - miss the forest
Re: Re: winter stove on 11/23/2005 02:45:00 MST Print View

Dr. Caffin,

good suggestion on the radiant heating of the insulated cartridge. also, "full-tilt-boogie" (good one!), now i know what the "f-t-b" indication on my stove dial means.

"pain threshold" at 40C? that's only 104F, and the cartridge is dry, not wet. "40C", a 'typo' right?

maybe the ans. is still pain threshold, but the 40C is a typo?

Edited by pj on 11/24/2005 01:56:37 MST.

Edward Ripley-Duggan
(edwardripleyduggan) - F
Boiling times/modding Xtreme on 11/23/2005 16:30:24 MST Print View

The CDC recommends one minute of boiling, not ten, so far as I can determine. I will use two minutes if I feel the source has a high likelihood of contaminants. However, I'm careful about where I gather snow, and generally only melt it.

On an ancillary point drawn from this thread, what modding for weight loss is possible for a Coleman Xtreme?

Ted Ripley-Duggan

Bill Fornshell
(bfornshell) - MLife

Locale: Southern Texas
Modding for weight loss?? on 11/23/2005 17:10:36 MST Print View

Ted Asked:
"On an ancillary point drawn from this thread, what modding for weight loss is possible for a Coleman Xtreme?"

Ted I don't understand the word "modding". Can you explain please.

John S.
(jshann) - F
Re: Modding for weight loss?? on 11/29/2005 18:07:18 MST Print View

Modding = Modifying