Guest Posted January 22, 2011 Share Posted January 22, 2011 hi, looking at lining up a second hand water maker for catalina 27 based in san diago... any suggestions??? Link to post Share on other sites
wheels 543 Posted January 22, 2011 Share Posted January 22, 2011 I think it might be better to list what you can find, rather than everyone suggest. Surprisingly they are not so easy to come across second hand. You can also make one yourself. The key to the entire system is the membrane. All you need is a high pressure pump which can be a Brass "waterblaster" (or you guys might call it a Pressure or power sprayer) pump, a motor to drive it and the pre filters. Either by a new pump or find a Petrol (gas) engine powered pump that the petrol engine may be trying to do the impression of a dead ant and remove the pump from it. Link to post Share on other sites
Guest Posted January 23, 2011 Share Posted January 23, 2011 Best low energy watermaker is the Spectra but they don't come ceap. Electronics are what let most watermakers down and you don't need electronics to make water. Best, simple (reliable) unit I have come across is Village Marine but their power consumption is quite high. On a boat that size you could look at a Pur/Katadyn 40 but these units use proprietory parts and any replacements do not come cheap. They do have the advantage of very low power consumption so can be run off solar but only make 4 litres/hr. I wouldn't recommend an engine driven watermaker. Link to post Share on other sites
Grinna 2 Posted January 23, 2011 Share Posted January 23, 2011 I wouldn't recommend an engine driven watermaker. That's an interesting comment Pete. Would you not reccomend an engine driven watermaker for this particular case or in general? I'm thinking very seriously about a watermaker (possibly one of the Open Ocean units built in Opua ... very robust, reliable and easily replaced common parts) but was put off the electric versions because they don't make nearly as much water as the engine driven ones. Interested to hear your opinions/experience. Link to post Share on other sites
Guest Posted January 23, 2011 Share Posted January 23, 2011 Hey Grinna, The reason I am anti engine driven models is that they only perform optimally at one fixed speed and this restricts your engine speed. A lot of people think they can get away with just adjusting the back pressure to compensate but reverse osmosis relies on feed water velocity along the membrane as well as pressure. Not enough velocity and you start developing problems with the membrane. Far better to use an appropriately sized DC motor to drive it. I like the Open Ocean models but do have some reservations about the Hawk pumps they are using. I would personally go for Cat pump. Never use brass for the pump as it will fail very quickly, even stainless steel has corrosion issues eventually. The Village Marine units use titanium pumps which are by far the most superior. About 1/2 my working week is spent servicing & repairing watermakers on boats and island resorts. Southern Man on here is another great source of info. Link to post Share on other sites
Grinna 2 Posted January 23, 2011 Share Posted January 23, 2011 Interesting that you suggest a DC driven pump to work the watermaker rather than a genset and 230/110V pump. We've been thinking about a watermaker for a while now and thought we'd have to install a genset to run an electric unit or have an engine driven unit. Genset is in the too hard basket and we're now seriously considering wind and solar power as supplementary charging systems. This puts us back to the engine driven watermaker option .... trouble is we already have 2 alternators and a freezer compressor (4 belts) driven from the engine ... not sure how we'd get another pulley or 2 on there and its probably not good to hang that much shite off an engine anyway. Hmmmm ...... still thinking Link to post Share on other sites
Guest Posted January 23, 2011 Share Posted January 23, 2011 If you've got the coin and want low power consumption then my pick would be the Spectra Cape Horn Extreme. This unit should run OK on Solar and/or wind so no need to run the engine whenever you want to make water. This model doesn't come with all the troublesome electronics and the only other real issue Spectra has had is feed pumps not lasting as long as they should. Simple enough job to carry a spare and replace if needed. That being said, Spectra are continuously developing their products and the service back up and advice is generally excellent. Link to post Share on other sites
Guest Posted January 23, 2011 Share Posted January 23, 2011 Village Marine do a 30l/hr 12VDC unit called the Little Wonder. I have this on our boat and have no complaints at all. Link to post Share on other sites
Farrari 4 Posted January 24, 2011 Share Posted January 24, 2011 You can also make one yourself. The key to the entire system is the membrane. All you need is a high pressure pump which can be a Brass "waterblaster" (or you guys might call it a Pressure or power sprayer) pump, a motor to drive it and the pre filters. Hey wheels, what sort of pressure are you talking about when you talk about a high pressure pump if I was to consider making one myself? I already have an electric high pressure (relative term) salt water pump on Farrari for washing the deck down. It's not going to put out 1750psi like my home water balster but could it be high enough for my limited use? I'm more thinking of using it for solar showers, deck water, etc than drinking water initially. We carry around 20L collapsible water containers for that purpose at the moment and it would be nice not to have to refill them from shore. I also have a 0.5u water filter on-board that I could use post desalination to clean up the taste and remove any bacteria if I needed to use it for emergency drinking water. I'd be interested in your thoughts. Link to post Share on other sites
Fusion 0 Posted January 24, 2011 Share Posted January 24, 2011 I have been having a look at build your own. http://www.cruisersforum.com has some good links. Most of the comments say go for volume and make a lot of water in a short time. http://www.trademe.co.nz/Business-farmi ... 493551.htm Pump $612.78 NZD Membrane $199.00 USD http://www.freshwatersystems.com/p-3849 ... 0-gpd.aspx Housing $300.00 USD 140 lt/hr at 13hp So 90min of engine running with a big alternator 4hp should be enough load for a 40 - 60 hp or 3 ltr Diesel. So for about $1500 - $2000 for all the bits watermakerSW30-2540.pdf Link to post Share on other sites
Farrari 4 Posted January 24, 2011 Share Posted January 24, 2011 Interesting. I was looking at this membrane as it was a bit cheaper. The one you referenced Fusion looks to have a higher volume and my be better for large volumes in a short time like you say. http://www.filtersfast.com/fx12m-GE-Smartwater-Water-Filter-membrane.asp Link to post Share on other sites
Guest Posted January 24, 2011 Share Posted January 24, 2011 [Hey wheels, what sort of pressure are you talking about when you talk about a high pressure pump if I was to consider making one myself? I already have an electric high pressure (relative term) salt water pump on Farrari for washing the deck down. It's not going to put out 1750psi like my home water balster but could it be high enough for my limited use? I'm more thinking of using it for solar showers, deck water, etc than drinking water initially. We carry around 20L collapsible water containers for that purpose at the moment and it would be nice not to have to refill them from shore. I also have a 0.5u water filter on-board that I could use post desalination to clean up the taste and remove any bacteria if I needed to use it for emergency drinking water. I'd be interested in your thoughts. 800psi needed for reverse osmosis but as I said before you have to balance the flow/velocity as well for efficient operation. The product water from a well built, well maintained unit will be superior to anything you get out of the tap. Generally prefiltration down to 5 microns is all that is necessary. Link to post Share on other sites
Fusion 0 Posted January 24, 2011 Share Posted January 24, 2011 Interesting. I was looking at this membrane as it was a bit cheaper. The one you referenced Fusion looks to have a higher volume and my be better for large volumes in a short time like you say. http://www.filtersfast.com/fx12m-GE-Smartwater-Water-Filter-membrane.asp It must be a Sea water RO membrane. The 20inch and 40inch SW RO Membrane is only $5 different. The other forum states 40 inch is the most cost effective by a mile. Link to post Share on other sites
Guest Posted January 24, 2011 Share Posted January 24, 2011 Interesting. I was looking at this membrane as it was a bit cheaper. The one you referenced Fusion looks to have a higher volume and my be better for large volumes in a short time like you say. http://www.filtersfast.com/fx12m-GE-Smartwater-Water-Filter-membrane.asp Not suitable for seawater reverse osmosis, only low pressure domestic drinking water supply Link to post Share on other sites
Fusion 0 Posted January 24, 2011 Share Posted January 24, 2011 Water quality high quality tap water has 500 parts per million TDS water makers run at less than 300 parts per million TDS Link to post Share on other sites
Guest Posted January 24, 2011 Share Posted January 24, 2011 I http://www.trademe.co.nz/Business-farmi ... 493551.htm Pump $612.78 NZD Not suitable for use with salt water, will fail in very short order. Link to post Share on other sites
Fusion 0 Posted January 24, 2011 Share Posted January 24, 2011 I http://www.trademe.co.nz/Business-farmi ... 493551.htm Pump $612.78 NZD Not suitable for use with salt water, will fail in very short order. And why? Link to post Share on other sites
Farrari 4 Posted January 24, 2011 Share Posted January 24, 2011 Looking at the picture it looks to have a lot of Brass componentry that may disappear in a short space of time via electrolysis (at a guess). Link to post Share on other sites
Guest Posted January 24, 2011 Share Posted January 24, 2011 I http://www.trademe.co.nz/Business-farmi ... 493551.htm Pump $612.78 NZD Not suitable for use with salt water, will fail in very short order. And why? Yep, brass. Also probably not rated for continuous duty, may not have ceramic pistons or stainless steel valve retainers. Link to post Share on other sites
Guest Posted January 24, 2011 Share Posted January 24, 2011 So for about $1500 - $2000 for all the bits Also need to factor in 2x skin fittings, feed pump if necessary, stainless or monel high pressure connections & hose, back pressure valve, high pressure gauge, switching, pre filtration (20 + 5 micron), flow gauge if wanted, high & low pressure protection etc. Link to post Share on other sites
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