Dual Survival Water "desalination"

J

jaymeister99

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I know, I hate to admit I have been watching Dual Survival and actually like it.:foot:

Did anybody see the episode that they made a desalination setup? Looked like a homemade still. Can this actually work for real?
 
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I saw it, and I say it works. I've actually done this, with a slightly different setup and on a stove at home, but in theory, it should work.
 
I may have just answered my own question. Anybody ever do the old trick of digging a hole, putting a can in the middle, then cover with a tarp and drop a pebble in the middle? This collects water that condenses on the tarp.

I would image this setup is basically the same principal but with a heat source to speed it up.

But is the water completely palatable with so much salt? I'm guessing yes since the salt won't evaporate.
 
I have read about this (and I saw and like the show) I believe it only takes the majority of the salt from the water but enough to make the water perfectly safe for drinking.
 
I saw it, thought it was a cool idea ! I really like watching Cody & Dave, they are very entertaining but at the same time they will show you some good stuff !
 
I saw this episode and I thought it was great. Unlike their first episode of the season everything seemed to be relevant and useful for the situation. As long as you keep the water in the still in the right temperature range and it is cool enough to condense coming out it will work. Unless the water boils over or there are volatile contaminates in the boiling water or the water dissolves something in the cooling coil or catch container this water will be some of the purist you ever drank.
 
Actually, they forgot one very important point: The water that comes from the end of that pipe is distilled water, so essentially pure H2O. It's actually the same water that you would buy in 1ga jerry cans to put into your steam iron or something like that. You can't drink that, because it will pull all the minerals out of your body to saturate itself with those minerals. Kinda like salt water dehydrates you from the inside out, but the other way round.

The salt (and everything else that is solved in the water) will stay in the can because it doesn't evaporate. NaCl (normal salt) becomes a liquid at 430°C, I believe. The evaporation point is much higher. Al the gases that are solved in the water evaporate, but they don't condense in the pipe.

So what you have to do if you ever have to use that setup is either pour some salt water or a little bit of sand into your freshly made distilled water. Then it's drinkable.

I've read about desalination of sea water in a book by german survivalist Rüdiger Nehberg, this post is just a little more than a sloppy translation of this part of the book.
 
That is what I thought...perfectly distilled water is not a good thing.
 
maethor said:
Actually, they forgot one very important point: The water that comes from the end of that pipe is distilled water, so essentially pure H2O. It's actually the same water that you would buy in 1ga jerry cans to put into your steam iron or something like that. You can't drink that, because it will pull all the minerals out of your body to saturate itself with those minerals. Kinda like salt water dehydrates you from the inside out, but the other way round.
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This isn't entirely correct. Distilled water is fine to drink and the majority of our freshwater water is highly hypo-osmotic relative to our blood (that is why blood tastes salty and drinking water doesn't). While our body fluids contain many minerals, it is really sodium (Na+) that constitutes the major ion regulating blood osmolarity.

Your logic is generally correct, that replacing blood volume with large volumes of hypoosmotic water will draw salts from your cells. However, we do not drink large volumes of water relative to our total body water content. Our bodies are made of 80% water with about 0.9% salt content. For a typical 70 kg individual, that represents 56 kg or 56 L of water and about 500 g of salt. At most we can only drink at a sitting between 2-3 L of water. Lets say you drank 3L of pure water, your body would have to supply this water with 27g of salt to make it isoosmotic with your blood. This reflects only 5% of the total body salt content which is hardly a difficulty for the homeostatic mechanisms of your body.

Besides, having not enough salts is not a very common problem as our diets, and in the case of the show (saltwater everywhere), has an excess of minerals. We obtain most of our salt from our diet, one reason why deer are attracted to salt licks because their predominately herbivorous food can be lacking in salt. Incidental ingestion of salt by the stars of the the show, even by virtue of breathing in salt-spray from the air, would more then adequately replace their body salt content. Plus their diet, including sea cucumber would furnish an excess of salts and minerals which would be flushed out by the kidneys.

Main point - don't be afraid of drinking distilled water.
 
kgd said:
It tastes flat to us because its lacking in oxygen, but is not in anyway unhealthy.
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Thats what I was thinking, its not that its bad for you, it just won't give you any additional benefits. Besides hydration!;)

Geez, where did you learn all that!?
 
kgd is a really fart smeller..... er, smart feller!! I have learned a lot from his posts!

I saw the episode you are talking about and enjoyed what Cody did with the distillery. Ingenuity and situation adaptation are keys to survival.
 
kgd said:
It tastes flat to us because its lacking in oxygen, but is not in anyway unhealthy.
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Yes this is correct....I was forgetting exactly what I had learned.

A little distilled water in a survival situation is fine. What you do not want to do is replenish repeatedly with pure water.

I used to be an endurance athlete and it became necessary to actually add salt to my water source otherwise I would suffer miserably on long rides. I was probably sweating and replacing larger volumes than one might hope to produce with a desalination rig in a survival situation;)
 
You can also suspend a pad of cloth over a boiling container of salt water or otherwise questionable water. The steam will saturate the cloth with condensed distilled water. You then wring out the water into a container - which could be you.
 
Ken, you just made me learn something. Or I chose to read it, either way, thanks for the informational post :thumbup:
 
unit said:
Yes this is correct....I was forgetting exactly what I had learned.

A little distilled water in a survival situation is fine. What you do not want to do is replenish repeatedly with pure water.

I used to be an endurance athlete and it became necessary to actually add salt to my water source otherwise I would suffer miserably on long rides. I was probably sweating and replacing larger volumes than one might hope to produce with a desalination rig in a survival situation;)
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Yeah, if you are losing lots of body water through sweat and not eating anything then you want drink something of the same salt content as your blood. This is the rational behind gatoraide and Pict's magic rehydration formulae with a little sugar as a pick me up. Again, most of our minerals come from the food we consume. If you are fasting over a long period of time and only consuming liquids, then adding in minerals to that liquid diet becomes necessary.
 
Distilled water becomes acidic fairly quickly, too. It dissolves CO2 out of the air, forming carbonic acid. PH ends up around 6.
 
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