In the West Marine catalogue (p.430/1999 ed) I saw a Pur Watermaker which claimed the ability to convert seawater to fresh water via pumping through a semi-permeable membrane. Claim was that 98.4% of the "salt" content was removed. It's pretty pricey at $500, and its yield of 2 pints per hour sounds about equal to the perspiration that would be needed generate the 800lb/sq inch force needed to force intake water through the membrane. Anyone have experience with such a unit? For a long trip along the southern coast of Bathurst Inlet NWT this coming summer , there are many large islands which may be (fresh) waterless. I plan on taking 3-10 liter MSR Dromedary Bags, which are certainly much cheaper than the above mentioned unit. Mostly I am concerned about a 5-6 day "involuntary stay" on one of these islands, due to wind. If there is sea-ice that far south, I realize that melt water on its surface will probably be potable, if accessible. Alas, last summers trip to NWT often reminded me of the biblical phrase " wind and clouds without rain" , i.e. fresh water doesn't fall from heaven to fill your canoe with distilled water! Just curious about other's experience with saltwater to freshwater alchemy. rich dempsey ridem_at_msn.com *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
In a message dated 1/31/00 4:18:26 PM Pacific Standard Time, RiDem_at_email.msn.com writes: << In the West Marine catalogue (p.430/1999 ed) I saw a Pur Watermaker which claimed the ability to convert seawater to fresh water via pumping through a semi-permeable membrane. Claim was that 98.4% of the "salt" content was removed. It's pretty pricey at $500, and its yield of 2 pints per hour sounds about equal to the perspiration that would be needed generate the 800lb/sq inch force needed to force intake water through the membrane. Anyone have experience with such a unit? >> Rich, I don't have any experience with water makers, but I did do some research on them for a trip I am planning. My conclusion was that the water maker you mentioned was too slow to use for anything but survival purposes, which is how it is marketed. Paddlewise's Cajun Gulf of Mexico crosser, Arthur Hebert <A HREF="http://homepages.gs.net/seacajun">Arthur Hebert's Sea Kayak Page</A> , sent me an email in the past saying that the higher capacity manual water maker he used on the crossing felt too slow and that if he had to do it again, he would get an even higher capacity model. Do a search for the Pur website, and you can see these higher capacity models, which I think ran in the $1000-2000 or even more range. Duane Strosaker <A HREF="http://members.aol.com/pirateseakayaker/index.html">Pirate Sea Kayaker</A> *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
At 10:44 PM 1/31/00 EST, Strosaker_at_aol.com wrote: > removed. It's pretty pricey at $500, and its yield of 2 pints per hour > sounds about equal to the perspiration that would be needed generate the > 800lb/sq inch force needed to force intake water through the membrane. > > Anyone have experience with such a unit? > >> You might try dropping this question on the Cruising World/Sailing World Message Board. You're more likely to find people there that have had experience with this unit: http://www.cruisingworld.com/cgi-bin/genlmesg.pl -- Wes *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
Rich wrote; ><< In the West Marine catalogue (p.430/1999 ed) I saw a Pur Watermaker which > claimed the ability to convert seawater to fresh water via pumping through a > semi-permeable membrane. Claim was that 98.4% of the "salt" content was > removed. It's pretty pricey at $500, and its yield of 2 pints per hour > sounds about equal to the perspiration that would be needed generate the > 800lb/sq inch force needed to force intake water through the membrane. > > Anyone have experience with such a unit? Arthur replied; The PUR 06 with it's 2 pints per hour of fresh water, would be for survival only. A LOT of work for little water. Of course to have a 06 water maker in your safety arsonal, would be great. Would surley be my last possible resort. I had a PUR 06 for a back up to my primary PUR 35 water maker. The taste, it grows on ya. Below I copied the post I sent to Duane a while back. >Duane wrote: Arthur Hebert, sent me an email in the past saying that the higher capacity manual water >maker he used on the crossing felt too slow and that if he had to do it >again, he would get an even higher capacity model. Do a search for the Pur >website, and you can see these higher capacity models, which I think ran in >the $1000-2000 or even more range. > Below is the post I sent to Duane a while back; Greetings Duane, I used the PUR 35 for my only water source for 15 days on a crossing. The manufacturer states a 1.2 gallon output per hour, that was probably in perfect factory conditions with several young bucks taking turns pumping, using fresh water (just guessing of course, no scientific data to prove that :>). I was only able to pump 32oz in approx.. 20 minuets, this was no fun after paddling 10 to 12 hours. I played a dangerous balancing act maintaining adequate hydration. If I were to do it over again I will purchase the new electric PUR 40 which can also be operated manually. There is a obviously a weight concern of 25 lbs.. for the unit itself not including the power source, not to mention the finical hit of $2200 US. I would back up the PUR 35 for it's reliability. I think they are practical in a "survivile"situation, a lot of work after or during a hard day paddling. If you have any sailing friends you may want to check to see if anyone owns a 35 that you can test. That could be a good way to see if it is worth the cost and effort for your use. Take care, Arthur Hebert *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
Speaking of "survival", does anyone have any info on distilling fresh from salt? I saw a website of a fellow who did it at the rate of one part fuel to one part freshwater distilled, not too effecient and no details as to how it was done. Or perhaps solar stills? I'm thinking of situations where one could become beach-bound by weather long enough to threaten on-board water supplies. Not to mention something to satisfy that natural (male) need to "tinker" with something (we never do grow up). I'll pass on the watermakers. They are heavy, expensive, power-hogs for luxury cruisers. A friend has one (which he loves) but he also has big bucks and a 40' sailboat. Bob *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
BaysideBob wrote: > > Speaking of "survival", does anyone have any info on distilling fresh from > salt? > I saw a website of a fellow who did it at the rate of one part fuel to one > part freshwater distilled, not too effecient and no details as to how it was > done. Or perhaps solar stills? Basically, to get the efficiency up, you have to make good use of the heat from the fuel by pre-warming the water entering the still pot with some of the "waste" heat from the condensing phase. That is SOP on the oil patch or in a refinery, where every calorie of waste heat is a few millicents lost, and every food Calorie is a penny lost. A practical thing when the operation is stationary and will be used endlessly. Some arid countries do this with sea water. Invariably, they have cheap fuel -- or, as in the Middle East, the fuel is "free:" in Saudi, natural gas has no market, so they just flare it off at the well head. At that price, it pays to make fresh water from salt. For we energy-poor sea kayakers, using a large surface-area unit which exploits the (low-grade) heat from the sun, and a condensing water source of coolness (read: sea water as the condensing fluid) is the only really "efficient" and practical method. Drawback: can't be done on the rolling deck of an enroute sea kayak. Can be done ashore, with some setup time. Good to know for a survival situation. I think NOLS has published some methods using black plastic as the solar collector for the heat. A Web search should reveal some tested techniques. -- Dave Kruger Astoria, OR chemist *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
As I understand it these devices are emergency devices only and can't provide enough fresh water for more then survival situations when you have nothing else to do but pump. cya -----Original Message----- From: owner-paddlewise_at_lists.intelenet.net [mailto:owner-paddlewise_at_lists.intelenet.net]On Behalf Of RiDem Sent: Monday, January 31, 2000 7:17 PM To: Paddlewise Subject: [Paddlewise] Saltwater to Freshwater "Devices" In the West Marine catalogue (p.430/1999 ed) I saw a Pur Watermaker which claimed the ability to convert seawater to fresh water via pumping through a semi-permeable membrane. Claim was that 98.4% of the "salt" content was removed. It's pretty pricey at $500, and its yield of 2 pints per hour sounds about equal to the perspiration that would be needed generate the 800lb/sq inch force needed to force intake water through the membrane. Anyone have experience with such a unit? For a long trip along the southern coast of Bathurst Inlet NWT this coming summer , there are many large islands which may be (fresh) waterless. I plan on taking 3-10 liter MSR Dromedary Bags, which are certainly much cheaper than the above mentioned unit. Mostly I am concerned about a 5-6 day "involuntary stay" on one of these islands, due to wind. If there is sea-ice that far south, I realize that melt water on its surface will probably be potable, if accessible. Alas, last summers trip to NWT often reminded me of the biblical phrase " wind and clouds without rain" , i.e. fresh water doesn't fall from heaven to fill your canoe with distilled water! Just curious about other's experience with saltwater to freshwater alchemy. rich dempsey ridem_at_msn.com *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ *************************************************************************** *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
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