watermakers

[davidwigler]

Sorry about the newbie question, but how do they work? Do they boil sea water and condense the steam? What do you do with them if the boat is in freshwater, make distilled water?

[boatwright]

high pressure pump pushs water molicules thru a membrane which will not allow the salt and other compounds through. may times more brine goes back overboard then product water is made. will work in fresh water and produces a more "pure" water, not distilled.

[Pascal]

it's all filtration... you have a low pressure feed pump (like an AC pump) sending raw water thru 25 and 5 micron prefilter (and possibly 50micron plakton filters) .

then a high pressure pump forces the water thru membranes, actual pressure varies but it's around 600 to 800PSI depending on temperature, salinity, etc...

about 10% of the total flow is fresh water actually sent to the tanks, the rest is dump overboard

actual nrs may vary, some watermaker are fully automatic and set the pressure, etc... others require some manual settings.

great where fresh water is expensive (bahamas), a pita otherwise because of filter changes and just the complexity of the whole system

[ron6785]

I agree with Pascal. It's one of the items I thought we'd use the most and it is helpful when staying at anchor, however unless you plan to stay on the hook all the time I don't think they're worth the expense and agrivation maintnance wise. They work best if used every day.

They are RO machines and can work in salt or fresh water, howeve in fresh water the high pressure pump is usually run at 150 rather than 800 in salt water.

[fixin-to-cruise]

Many use pressure washer pumps (CAT Pump is on mine) and regulate the pressure to 850psi. They are a little electricity hungry so you need to run your genset or be plugged in. Some are noisy so choose accordingly!

[wmfels]

if you're in the market for one i have one. it has the cat pump and filters to go with. the hour meter shows .7 this was on my late fathers hatt. after my father told my mother how expensive water is in the bahamas, he installed it, my mom said they poured one glass of water, and that was it!! never even took the boat to the bahamas! lol that was my old man for you. anyway i now have the boat in minnesota and removed the watermaker. we dont need them here.. the bearings are locked up from sitting,thats pretty much all the boat ever did, but theyre easy to rebuild, if you're somewhat handy. cat pumps are made right here in minnesota, popular in the carwash industry,that was our business so ive rebuilt my share ...i have many other more important things to fix on the boat, so the watermaker is definately last on my list..not sure how many gph it produces , but knowing my dad its plenty ! anyway thats my story and if your interested send me a pm

[wmfels]

after a couple interests in my watermaker i checked it out better and only the motor is stuck the pump is fine if anyone else is interested in it send me a pm with your email and i'll send you pics and info

[Angela]

Knowing the gallons per hour will be key as that is the difference between a $500 watermaker and a $10,000+ watermaker. What is it?

[wmfels]

still trying to figure that out but i think around 300 gallons per day from the research my mother did...i'll have to confirm. going to the marina this week there maybe manual onboard