hot rock still

something i haven't read of seen before...
http://www.us-rsog.org/_disc12/00000338.htm

I like this concept. I may not be totally understanding how it works. If I'm reading it right, it's just a solar still using hot rocks instead of the sun. I think that's a very good idea.

I'm going to go add about a 4x4 piece of visquine and some surgical tbing to my PSK right now.

Has anyone tried a still this way, and if so, any tips on making them work efficiently?

Luke

Maybe I'm just not picturing this right but this whole idea seems pretty inefficient. You have to build a fire to heat your rocks. You need to build or dig the equivalent of a solar still, in mud no less <img src="images/graemlins/confused.gif" alt="" />. And then use the hot rocks to boil water from the mud? It seems labor intensive for the return. Why not just strain the water from the mud through a sock, handkerchief, whatever, and then boil it to purify (or use the PA tablets that we all have) Like I said, maybe I missed something

Ed

This works if you have matches and a garbage bag but no pot or container. It's all about what you have with you for improvisation. Without a pot to boil the water and no container to hold the water for the puri-tabs if you can light a fire and find a garbage bag you can create distilled water this way. Still very labor intensive but effective given enough wetness and enough fuel and a little bit of waterproof material for the condenser.

I have no doubt that it would work, I'm just doubtful that the sweat equity required would be offset by the water returned. If I've got enough plastic for fabricate a condenser then I've got enough to whip up a container to utilize my PA tabs. I probably will file this info away, right next to "how to build a solar still", but it probably won't be the first option in my bag of tricks.

Ed

In the Aus Army Survival School (Darwin) they teach soldiers who find themselves with no plastic and no containers to dig a small pit (maybe 1/2 bucket sized), line it with paperbark or clay, fill cauldron with water, heat rocks as hot as possible, and using branches as tongs to drop hot rocks into water. Take off shirt, place on branch, hold in steam until saturated, wring out clean water. Very labour intensive but you need only fire, water and rocks. You can also condense that steam on the kicked-out windscreen of your vehicle, which will of course need to be supported at an angle over the cauldron but which will trickle the condensed water to the lower edge for collection.

Rgds
Bones

The regular old solar still seemed to require an enormous hole, 3x3ft or 3x4ft. I always assume that you needed the big hole to expose more damp soil for distillation. But if you've got a smallish hole (maybe a ft in all dimensions) with mud in it, maybe that would work. Water flows to the lowest point, & if you condensed what was in the hole, maybe more would drain into it.

This is just theory, mind you! But so were solar stills.... <img src="images/graemlins/smirk.gif" alt="" />