Solar still not for desert

[crazydave]

there are a lot of urban myths and often things are poopooed by people who couldnt get it to work or have read bitter accounts by others which can be as guilty as faulty manuals. like the bullet trick mentioned. the manuals also say that you need to make sure the bang doesnt blow the tinder ball away and to cover the ball with your hand or boot. the principle of using the flash to light a fire is a sound one. anyone on the IBSR ranges who has inadvertantly set the grass alight during a pepper pot will agree with me as i've done it and seen it done several times. peat fires on the ranges are also common and not just from the use of tracer rounds. tying a loose grass ball around the muzzle and firing into the ground would probably work as well and i've not read that in a manual

same with the solar still, the physics are sound as anyone in a sweaty tent or poly bivvy bag will agree with, the variables are down to whether the ground has enough moisture to trap in the first place. if it doesnt then you either have to supply the water yourself or change to a dew trap.

sometimes though these things are like fishing kits - they are proactive in getting you to do something instead of lying there feeling sorry for yourself.

 

[Hoodoo]

I believe this is the original citation.

 

[Graham_S]

I thought it was something like that.
There are quite a few things in even the most respectable survival manuals that simply do not work.
An Idea gets published and then it spreads around as gospel without anyone checking if it actually works as described.

 

[Armleywhite]

1 may not be sufficient to keep you going for long, but I would imagine that if resources permit, several would be a very good source of water.

 

[BOD]

I have just realised that the original link in the first post is now broken.

So to recap for those interested. Dave Alloway, the survival trainer for the Texas Parks and Wildlife Rangers, among others, said that the effort in making a solar still is simply not worth it in desert conditions.

 

[IanM]

For those interested small, compressed, cellulose sponges made to wipe the bit of a soldering iron when moist are available from shops that sell soldering irons e.g. Maplins.

http://www.rapidonline.com/Tools-Fa...ies/Soldering-iron-tip-cleaning-sponges/61554

You are probably better off slicing a damp cellulose sponge and drying it between weights to compress it to a manageable size.

 

[rik_uk3]

Ray Mears set up a solar still in one of his programmes, if I remember right, he thought you would sweat more water building it than the end results of the still

 

[Hoodoo]

Ray Mears set up a solar still in one of his programmes, if I remember right, he thought you would sweat more water building it than the end results of the still

That's the usual conclusion I see. However, if you built it at night, you would save a lot of water.

A person in the desert can lose 2 liters H20/hour by sweating. If you lose more than about 15% of your body water, death is not far away. So under heat stress, it’s truly a life and death issue. I am thinking the original idea was not to make these as a last ditch/last minute effort but build them to supplement your water supply before your water supplies are low. However, this raises another issue. Some desert trekkers factor in that they will supplement their water supply with still water as part of their planning and I think desert survival experts like Dave Alloway said that's a serious mistake because of the inherent unreliability of the still.

 

[crazydave]

its taught in the military and some troops have spent a lot of time looking at this as to them survival can be very important. some ranger units were teaching to use a poncho as the cover which might work but nowhere near as efficient as a clear cover. I've make a few in different areas when I had nothing else to do in the same way when waiting for the chopper home we would go on a forage or try and rustle up a bow drill

the point is that they do work and can produce water if you can supply a source of dead moisture such as stagnant water, vegetation, elephant dung if you dont fancy the hardcore method, sweaty clothes or widdle. its generally not a nice drink but it is sustaining in the same way as the two bottle recycled widdle trick works but isn't pleasant. they recycle water better than producing it out of thin air which is what people generally expect. if they didn't work then they wouldn't put them in lifeboat kits. similar to using a transpiration bag which doesn't allways work but when it does can produce enough fluid to stop death. picking the right spot such as the bend in a dry river bed or a natural dew pond also adds to the chances of sucess.

there are also a lot a variables. some versions advocate lining the pit with piles of rocks and opening the still up at night to allow dew to form on the rocks which is then harvested when the still is put back to use the following day. I havent tried this so cant vouch for it.

troops first out in the desert will go through up to 20 litres of water a day, after a few weeks as the body aclimatises and shuts down its internal heaters this drops down to 8 or 9 and even less so you also sweat less, it must also be added that scientists have recently poo pooed the minimum daily water requirements as another urban myth allthough I am not claiming that dehydration is not serious.

sometimes though its better to die trying than not to try at all.

 

[Hoodoo]

troops first out in the desert will go through up to 20 litres of water a day, after a few weeks as the body aclimatises and shuts down its internal heaters this drops down to 8 or 9 and even less so you also sweat less, it must also be added that scientists have recently poo pooed the minimum daily water requirements as another urban myth allthough I am not claiming that dehydration is not serious.

Those recent studies on daily water requirements were based on humans at thermoneutrality and really don't apply to the kinds of conditions faced in the desert, where the ambient temperatures often exceed body temperature.

 

[Tengu]

Ive been thinking.

Could the writers of the books have been getting the pit type still mixed up with the inflatable water purification still I think someone posted a pic of?

People do use those in deserts, often on their houses.

 

[BOD]

Except where there is moist ground or a source of undrinkable water - wee, poo, seawater etc. the general consensus seems to be that
there is no use for a solar still

I wonder though whether it would be better to bag vegetation with the plastic using the transpiration method than kill the plant by tossing it in the still?

 

[crazydave]

a transpiration bag would only work with a plant that breathes properly, desert scrub plants and cacti wouldn't be too kind to the bag so you'ld probably have to chop up the plant anyway.

I wouldn't say the consensus is that they dont work as like anything its down to variables and how or if you can control them. to rule them out is foolhardy but having the knowledge to use them if desperate like being with a broken vehicle and draining the coolant to 'still' the water out of it. Back in the days of the mg34 and the water cooled vickers machine guns troops used to drink the coolant water when there was nothing else desperation being the death of sqeamishness.

You might not get much water out of one in one place like a desert wadi but drop down to the coast and it might become a viable way to desalinate seawater to keep you alive. in such circumstances you would try anything to get a source of suitable water when no other options are open to you. digging a pit for a still at night might be a suitable way to keep you warm enough to survive the freezing desert nights and provide topsoil for a shelter to keep you cool during the heat of the day.

you should never rule anything out which is one of the better things you see on the born survivor shows once you get past the personality, the prudishness of some of the viewers and the health and safety issues. its one thing greatly lacking but which does occasionally surface in the more acceptable shows. we call bg foolish for eating all sorts of creepy crawlies but no one complains about the rm sea survival when the guy looked forward to eating fish eyes because they were mostly water, or rm cooking shrimp in the jungle, eating mealy worms, wichity grubs or toredo worms with the aboriginals.

does anyone remember being given foil sleeping bags on long haul flights? you could tip half a pint of water out of them afterwards like a human transpiration bag - no wonder it didn't last and they went back to blankets

 

[Schwert]

You cannot distill water off of radiator coolant with a primative still. Propylene glycol and water codistill....so get that notion out of your head.

 

[crazydave]

fair nuff I was under the impression it could be separated. I shall amend the internal manual and delete the original source