Where to find the cheapest RO de-salination membranes

[jheldatksuedu]

Originally Posted by Canibul

I'm in the same general boat, in that I need a decent watermaker between now and November and don't yet have the $ 4000 for a 20 gph one. This is not rocket surgery.

You don't need a 20gph system, you are in a 36 ft boat..... go back to study what you really need.

Listen to the naysayers, we are all smart people, I've taught engineering for 30 years, I also planned on building a watermaker, studied the systems, but I got lucky, I found a $5000 katadyn in a yardsale box for $10. I'll probably need new elements, that's what attracted me to this post in the first place. I've looked and I haven't found anyplace for cheap ones.

Salt water is tough stuff, and more tough at 1000 psi and higher flow rates. A cheap pressure cleaner is lucky to last 6 months as a pressure cleaner used 5 times, and that's with fresh water. I'm not saying you can't build one, but cheap, easy to fix, etc. is not going to happen unless you luck into a good sized comercial stainless pump. We are all trying to save you a headache, and offering our opinion. If a cheap one could be built, somebody would and you could buy them. I pinch pennies harder then anybody I know, and I also understand engineering. I also will bend over to pick up a penny on the ground, I expect I've got about 86 cents by now, might make a dollar before I die... I did find $40 once, and did my best to make sure I tried to find the person that lost it.

[Canibul]

you are wrong on both counts. I am not in a 36 ft. boat. I spent 40 years in the offshore/underwater business designing, building, and using underwater acoustic systems. I know a little about glass, stainless, anodized aluminum, seawater, and pressure vessels. O-rings. Connectors. Titanium. And I need a 20 gph water maker.

But I'm looking for a used one. I think you got me mixed up with someone who wants to build a cheap one from scratch. I don't do Harbor Fright.

[hellosailor]

Canibul-
You may not find a lot of used ones. I suspect people who upgrade, upgrade by swapping their whole boat for a bigger one, since there's all that plumbing and assembly to change if "needs" change.
But the marine consignment and secondhand shops, like Sailorman in FLL, might have used units from boats that were insurance totals, or whatever other source. I'd try calling around to some of those guys, since they often will suggest someone else to try calling for something they don't have.

[Lepke]

Ebay or Amazon

[jheldatksuedu]

Originally Posted by Canibul

you are wrong on both counts. And I need a 20 gph water maker.

But I'm looking for a used one. I think you got me mixed up with someone who wants to build a cheap one from scratch. I don't do Harbor Fright.

I was just going on your description, 12m sounds like 36, actually closer to 40 I didn't put it to a calculator, but still most in a boat that size don't need 20gph. The rest of my comment was not necessarily aimed a you, but somebody that thinks they can get by with a cheap pressure washer pump designed for fresh water. They also often haven't figured out the capacity they really need, they think about somebody taking a luxurious shower, and not about having any tanks to spread the load on a smaller system.

As for finding a cheap system, that and the word marine are mostly mutually exclusive. Most Marine salvage shops I have been in, charge as much as they can, they price things so it hurts, hurts a lot, you are almost always considering that for 40% more I can get new with a warranty, and your are probably correct. If it is something with moving close tolerance parts definitely correct. The only cheap salvage is if you are doing the salvage work yourself. I have found that eBay is good for larger marine equipment, people that have a million dollar boat normally don't search on eBay to find a bargain, they get out their gold card and buy new and then pay somebody to install it. EBay is not cheap when it comes to time invested, you have to spend the time to make up a good automatic search that weeds out all the chaff, and then check your email every day, and look at what the search finds, then decide if it is what you need, how much it is worth and probably have a sniping program, often ending up with nothing for all the time invested. Somebody else just bids a little bit more. There is no free lunch, except maybe at a church....

[colemj]

Originally Posted by jheldatksuedu

but still most in a boat that size don't need 20gph.

What does boat size have to do with water usage? Usage is more determined by user-preference, activities, cruising grounds, etc. The only place where the size of the boat could matter is in washing down the boat - where the difference between 35' and 55' is minimal.

Mark

[Canibul]

Originally Posted by colemj

What does boat size have to do with water usage? Usage is more determined by user-preference, activities, cruising grounds, etc.

Mark

no kidding. Put several women with long hair, wardrobes, and a washing machine on board. Add a dog. THEN tell me about your fresh water usage lol...

I looked at several used systems on eBay, and quickly realized that they looked pretty neglected even in the photos. So add the immediate cost of new membranes and a rebuild kit to any eBay system, I suppose.

Can someone point me to a good pro/con write up on 12 volt vs 110 volt watermakers?

[matureee]

Originally Posted by Captain Bill

Odd that you would suggest he go forward with crap pumping hardware when you chose instead to do it with an actual water maker pump. No one said you can't build your own water maker, but using components that were never designed to be in contact with high pressure salt water it is simply not going to last. I have no doubt one can build a more efficient water maker than some commercial units. Some of their decisions are based on marketing where you can make decisions based on function if you choose to do so such as more direct line flow routing because you are not trying to make it fit in the smallest possible box.

I prefer to communicate by pointing out what does work rather than jumping up and down on somebody's ideas. Sorry that you find that odd.