melting snow

[thaycw1]

Hello,

I do some winter mountaineering, and normally I have to carry 4-5 liters of water, despite the fact that I'm surrounded snow. I'll sometimes carry a stove to make water, but that's such a hassle that it's usually reserved for camping trips.

Does anyone have any experience using the MRE heater to melt snow, to make water in such cases? Is there any reason this wouldn't be safe to do, as long as you didn't drink the water that was in direct contact with the heater? If no problems, how much water can you reliably get per heater packet?

thanks,
Chris

[housil]

Hy Chris, welcome to forums.

We had the topic if you can use snow to run a FRH.

I tried to melt snow with a FRH and the problem with FRH is, as colder (+older) it is, as slower runs the chemical reaction. At -5°C (23F) the FRH didn´t work at all.
Whenever I'm on winter "excursions", I always use a(ny) fuel operated cooker. This can melt you enough snow to get a useful amount of water.

[thaycw1]

Thanks for directing me to that string, Housil! In that string it seems that most people were trying to activate the reaction with the snow itself. Did you try using liquid water (not frozen because stored against your body) to activate the reaction, and then melting the snow? Or are you saying that even that didn't work?

Even if the heater did somehow work at that temperature, are we saying that it would not be safe to drink that melted snow? If so, what is the reason for that? I can understand if the water comes in direct contact with the heater of course, but if it doesn't, why would that present a risk?...

thanks!
Chris

[housil]

Thanks for directing me to that string, Housil! In that string it seems that most people were trying to activate the reaction with the snow itself. Did you try using liquid water (not frozen because stored against your body) to activate the reaction, and then melting the snow? Or are you saying that even that didn't work?

You are right, actually we tried to operate a FRH with snow instead with water.
But even with water, the heater didn´t get hot enough to thawing the snow right on it. I guess it slow´s the chemical reaction down. If it´s cold outside, it happens that the FRH don´t get hot, just (luke) warm.

Even if the heater did somehow work at that temperature, are we saying that it would not be safe to drink that melted snow? If so, what is the reason for that?

Drinking melted snow is always a little bit "difficult" as melted snow contains no minerals nor any salt etc. You just get purified water and better add 9g/liter of salt to make it isotonic (0.9%)

I can understand if the water comes in direct contact with the heater of course, but if it doesn't, why would that present a risk?...

There is no risk. MREs have an extra bag to heat up beverages, coffee etc via the FRH.

My personal opinion is, it takes too long and you don´t get enough water in a proper time using a FRH to melt snow if it works at all.

As you see on my picture:

even after 45min (!) the FRH couldn´t melt the snow right in it

[thaycw1]

Okay – thanks for the info!