DIY Watermaker

[Tellie]

Originally Posted by beau

Tellie, i appreciate your comments and support.
I have been told I can get 40 gallons per hour of fresh water from 2 x 2 1/2 X 40 inch membranes in series and yes 40 US gallons is 150 liters, my mistake.
yes, I have a 12 v boost pump which cost $65.00.
The pressure washer is 6.5 Hp driving a Brass (italian designed pump) max pressure is 3,500 psi. of course I wont be using more than the 800 -1000psi.
the gasoline motor will be run outside (of course)
i have a complete spare pump which cost $150.00, a full set of seals etc cost $35.00.
I am replacing the original plungers with ceramic ones.
http://www.westward-ii.com/PDF's/How...watermaker.pdf
Is the design I am using.

I appreciate your comments and support

You have my support all the way. Keep us updated often as to your progress and thanks for taking my comments in the content they were meant. I know of Leo's design. One thing I like about him is that he seems to be always updating his site with some current info. One thing I'd recommend is using only pleated pre-filters.

[Brent Swain]

Originally Posted by Stillraining

Mind sharing your source Brent...you can PM me if you'd rather.

General pump , model number TT911.
3GPM, 1700 rpm.

[cat man do]

Originally Posted by Brent Swain

Any pressure washer pump with ceramic plungers, which can put out at least 3 GPM, is fine for a water maker, and is far more ruggedly built, for much higher pressure than a watermaker will ever use.
They can be found for under $3
Italian made ones are the best.

A few numbers short

Originally Posted by Brent Swain

Any pressure washer pump with more that 3gpm output and ceramic plungers will do. I bought mine, a general TT911 for $325 CDN from Mancorp in New Wesminster, but I have seen them on sale at Princess auto for cheaper.

[foggysail]

[QUOTE=Tellie;541881] One thing I like about him is that he seems to be always updating his site with some current info. One thing I'd recommend is using only pleated pre-filters.[/QUOTE]


Tellie---

I always read your posts, usually there is at least one gold nugget there.

Foggy

[Therapy]

[QUOTE=foggysail;542373]

Originally Posted by Tellie

One thing I like about him is that he seems to be always updating his site with some current info. One thing I'd recommend is using only pleated pre-filters.[/QUOTE]


Tellie---

I always read your posts, usually there is at least one gold nugget there.

Foggy

Keep diggin.
There is usually more than one.

[Brent Swain]

Apologies for the typo. Never took typing seriously enough in high school.
Who knew we'd be using it so much.
I often see 3GPM pumps with ceramic plungers on sale for under $300.

[JohnnyO333]

Hello Everyone, 1st time poster, LONG time stalker HA !

I have read and learned quite a bit from this long thread that has survived the years. With that being said, I have a defined set of requirements which revolves around seasonal cost.

I am a commercial fisherman, and I live aboard a 42ft trawler 5-6 months out of the year, which is split up between 2 seasons. The other 6 months she is in port by herself.

Concerning the pumps, I don't need anything that would last YEARS... something that could be changed out cheaply once a year or twice a year would be fine by me.

I run my main engine at minimum 12-15 hours per day, so a pulley driven pump is ideal ! I'll make my water in the morning during warm-up or during the evening during cool down ...... Both take about 30mins with the main idling around 800rpm ...

I need 40-50 gallons per day for showers / general cleaning.

Can someone tell me which is the cheapest pump I can get away with ? I don't care if this is something I would have to replace once per season, it needs to be CHEAP but work. I'll keep a spare onboard. I would rather have 2 (150.00) pumps onboard , then 1 $750 pump ...

I know one area I cannot skimp is in the pressure vessels / membranes. But I would like to know the cheapest of these I can get away with also.........

Any and all help is appreciated.

JohnnyO
"Band of Brothers"
Southwest Louisiana (Cajun Country)

[Cheechako]

I was lucky enough to obtain a 120v 1.5 hp watermaker unit used. The fancy control unit was bad. I salvaged the Cat HP pump off it and engine mounted it, along with the membranes. Eventually I replaced the 3 small length membranes with one 36" one, due to corrosion etc of the used tubes/fittings. The other unit I built I bought the parts from Aquamarine in Deer Harbor Wa. They used to specialize in the do it yourselfer. I believe it had a Whale (?) german made pump. You might get some insight by talking with Aquamarine (Ph: 1-800-376-3091 or (360) 376-3091 ) if they are as helpful as they used to be. Basically you need a HP pump like a HP washer uses, but you need one that will stand up to salt water and put out at least 600 psi. A good pump like a cat pump should last for years even in your application. In fact maybe especially in your application, as using them is better than having them sit. My unit put out 24 GPH with one membrane, and was basically manually controlled using a gauge and a needle valve to control operating pressure. If you have a gen set onboard it may be cheaper and simpler to just do a direct drive A/c unit, then dealing with electric clutches etc.

[JohnnyO333]

I want pulley drive.
I want CHEAP pumps.
I need 40-50 GPD

I don't want anything expensive I can't afford to replace. I will keep 1 spare of everything onboard.

JohnnyO

[foggysail]

Originally Posted by JohnnyO333

I want pulley drive.
I want CHEAP pumps.
I need 40-50 GPD

I don't want anything expensive I can't afford to replace. I will keep 1 spare of everything onboard.

JohnnyO

Someone here in the Cruiser's Forums sells a book describing how he built a huge (40+gallon/hr??) watermaker for less than $700 or so. Guess you have to buy the book.

Foggy

[JohnnyO333]

Foggy, have the information on how to purchase the book ?

I've always found great value in E-books.

Thanks

JohnnyO

[SaucySailoress]

Hi Johnny O

There have been many many discussion about this topic - take a look on the google search tool at the top, or even easier, here's a link to the results: watermaker - Google Search

Incidentally, we bought one in Holland and brought it back in boxes to assemble - it was actually the best option when we considered price and effort.

[thomasow]

Hello.

Interesting (and long) thread. FWIW, we completed a home-built water maker this summer (Kubota / DC Gen / 40+ GPH) and I have posted the design (complete with part numbers and costs of parts used) here:

mv.VikingStar: Water Maker

It is a simple design, and I will say that most the cost was in the Small Parts!

And to the issue of HP pump, though I found a killer deal on a CAT SS pump, I think if one used the Brass head pumps that would work well - one commercial unit I puled parts from had a brass head pump. Though the pump was eroded out and unusable, I noted the water maker had over 3000Hrs on it! So perhaps it is a reasonable approach.

-al-

[foggysail]

Tom---

YOUR POST WAS CERTAINLY REFRESHING!! Especially:

"Towards the end I needed to just Get It Done. As it is, we are at $5000 and perhaps 4-5 YEARS of aggressive EBay searching! " From you URL pointer.

I am into my 2nd year building this thing of mine that I expected to have finished last spring!!! OK.....so I made some simple changes along the way but then again, maybe they were not so simple. I planned from the beginning to have my unit somewhat automatic. I had the controls completely sketched with all the needed electronic components. Things were fine until Dave (Go-Boating-Now) commented that a unit utilizing today's technology would not use discrete electronic components, they would use modern controllers. Those were not his exact words, maybe he said "he would use modern controllers!"

Well that did it for me! AND DAVE, IF YOU SHOULD READ THIS, I want to thank you for inspiring me to use a modern approach!

So all I had to do was relearn C after 20+ years, in this case Microchips C18 software language, become familiar with one of their microcontrollers, a PIC18F4550 (about 260 pages) plus learning one of the newer serial communications buses I2C.

Yes indeed! Time flies!

My design uses a display panel to display all the programmable features/functions of the machine such as run time, H2O pressure, product flow for example. I am nearly finished with my software and will be testing it within the next month. Not until then can I begin doing the plumbing assembly. Oh, my control panel with have a CAT 7070 mounted which I know is overkill because my system is powered with a 2HP electric motor, a couple of push button switches and a display panel. No large flow gages or water pressure gages. That stuff is electrically monitored and displayed on my programmable display.

If I have enough time, I will get my machine installed this season....hopefully!

But CONGRATS to you on your achievement!!!

Foggy

[goboatingnow]

Originally Posted by foggysail

Tom---

YOUR POST WAS CERTAINLY REFRESHING!! Especially:

"Towards the end I needed to just Get It Done. As it is, we are at $5000 and perhaps 4-5 YEARS of aggressive EBay searching! " From you URL pointer.

I am into my 2nd year building this thing of mine that I expected to have finished last spring!!! OK.....so I made some simple changes along the way but then again, maybe they were not so simple. I planned from the beginning to have my unit somewhat automatic. I had the controls completely sketched with all the needed electronic components. Things were fine until Dave (Go-Boating-Now) commented that a unit utilizing today's technology would not use discrete electronic components, they would use modern controllers. Those were not his exact words, maybe he said "he would use modern controllers!"

Well that did it for me! AND DAVE, IF YOU SHOULD READ THIS, I want to thank you for inspiring me to use a modern approach!

So all I had to do was relearn C after 20+ years, in this case Microchips C18 software language, become familiar with one of their microcontrollers, a PIC18F4550 (about 260 pages) plus learning one of the newer serial communications buses I2C.

Yes indeed! Time flies!

My design uses a display panel to display all the programmable features/functions of the machine such as run time, H2O pressure, product flow for example. I am nearly finished with my software and will be testing it within the next month. Not until then can I begin doing the plumbing assembly. Oh, my control panel with have a CAT 7070 mounted which I know is overkill because my system is powered with a 2HP electric motor, a couple of push button switches and a display panel. No large flow gages or water pressure gages. That stuff is electrically monitored and displayed on my programmable display.

If I have enough time, I will get my machine installed this season....hopefully!

But CONGRATS to you on your achievement!!!

Foggy

Agh well foggy that's what you getting listening to me. !!!

My experience ( I've since sold it) is that building your own can be cheaper but isn't necessarily so, especially compared to the cheaper end of the non-energy recovery professional units.

In my case I did a few things differently. Firstly I'm convinced that brass pressure pumps are adequate, subject to a few provisos. One they will not last anything as long as SS or titanium ( mind you I,m dubious about SS at the best of times ) but they are cheap. Secondly be aware that the oil seal can fail and contaminate the water that can be a problem on cheap heads. So learn to dismantle and inspect and replace. Thirdly I have a programmable unit ( mines uses a atmel controller) so I rigged it to always fresh flush the pump after every use, never leave seawater stagnant in the pump.

I used a needle valve and motorised it with a simple motor gearbox unit. That's was still cheaper then a cat back pressure regulator and has the advantage that the system can be adjusted remotely. It's very handy to not have to bring high pressure piping any distance to allow access to the pressure regulator.( as foggy pointed out this also applies to remotely sensing pressure and flow. Also my unit offers the possibility to balance pressure against product flow to compensate for salinity and water temperature. ( I didn't do that yet that's for version 2) I have a purely electrical panel that uses a 3.5" windows CE panel PC to display and control the watermaker and this communicates to the micro controller. As I said this keeps the high pressure runs very short. From inspection I'd say I'll would have gotten 4years from the pump. This assumes good sediment filtering etc.

I built mine because I like building things. If you do, great if not, its not a good way to save money. The small things like reliable high pressure fittings and hoses etc can get you.

Danfoss are now beginning to ship small volume rotary energy recovery units and hopefully as prices fall this will let us DIY with them as well as spurring more competition to the Clark pump method, which while useful and cheap is a poor example of good energy recovery.

Dave