Disposal of Water Maker Brine

[nautiguy]

I think that I am going to install a small water maker soon, and I'm wondering what to do with the brine that is the waste product of the process.
Installing the water maker will require me to drill in a new through hull fitting for raw water intake, and I would like to not have to drill another hole in the hull. So, I am thinking of directing the discharge into to bilge pump sump. Besides not needing another through hull, it seems to me that the discharge will pickle the planking.
Any thoughts will be much appreciated.

Norm

[Candyfloss]

You can't "T" it into the sink drain?

[RFNK]

Generally speaking, dry bilges are desirable as it's undesirable to increase the humidity inside a wooden boat, so pumping water into the bilges isn't a good idea. Pickling planks also pickles fasteners - not a good thing either. As Graeme suggests, why not t-join the watermaker waste into the sink drain (assuming you have one) or a cockpit drain? Rick

[nautiguy]

Teeing into the sink drain may work, but the run of the discharge hose will be about 10 feet of fairly low slope. I would like to make the sink drain option work.
Plumbing to a cockpit drain will not work because the water maker will be lower than the cockpit sole.

[Lew Barrett]

Hull penetrations are not fun to contemplate, but sometimes they represent the best alternative.

[htom]

This is not a good plan, in my opinion. While the water maker is lower than the cockpit sole, is the brine outlet lower than the cockpit drain through-hulls? Is there another brine outlet?

[chasbartlett]

Don't do it. "T" it into the engine exhaust hose or somewhere else.

[Candyfloss]

I agree, it's fraught. Your brine outlet at the watermaker would have to be higher than the sink or you risk flowback. Eccc! It was just a suggestion. The best option is a dedicated thru-hull on the side oposite the intake. Put more stuff on your boat & it gets more complicated.

[Lew Barrett]

The last several posters (myself included) are pointing you where you need to go. Shared penetrations and through hulls are not recommended as a rule. At best, if there's a failure, you lose two functions, and potentially it makes diagnosing problems more problematic.

[ssor]

For your through hull to serve as you wish the water maker will have to be above the WL.

[Bob Cleek]

Uh... just curious, but why are you installing a desalinator at all? Are you planning to do some long off-shore voyaging? They are an awfully expensive way to get fresh water unless you expect to really, really, need it, especially in quantities that would permit unrestrained consumption aboard.

[Lew Barrett]

That's a fair question. In addition to offshore work, they can be handy up north where fresh water is hard to come by, but overall I (and most people I know) find it's easier just to conserve and/or carry extra water for drinking and cooking outside the tanks. Use the tankage up first, then the bottled.

We carry 260 gallons which can last us a good while. I also have a sea water pump onboard for dish washing and such, But many modern boaters can't live without using 20 or 30 gallons a day. I can shower (luxuriously) with 3 gallons of water and get by on an additional 3 gallons, absent dishes, whcih are the most water wasteful items on board. If my wife is as frugal, we can easily last 2 weeks with the water we carry. But in cruising, I've never gone that long without finding a place to top off our tanks.
Some places have better water than others thiough, and you do not want to take water from a questionable source. The best situation then is to have a friend with a big water maker. :D

[ssor]

If you restrict your fresh water use to cooking and drinking and wash your body wish a wash cloth you can get along on about a gallon per person per day. We save the water from cooking pasta for washing dishes. An automatic pressure system uses far more water than a hand pump. Raw water works fine for washing dishes and bodies. A fresh water rinse is a nice but not necessary.

[BarnacleGrim]

If you get a good quality seacock there shouldn't be any risk involved. Only cost and labour. But you may avoid a lot of problems later on by doing it that way.

[nautiguy]

Thanks for all of the responses.
We are planning some long distance cruising and only have tankage of 40 gallons of water. We are fairly frugal with our water usage, but would like to have more than absolute minimum.
As far as brine disposal is concerned, the problems are as follows:
The waste side of the water maker will be at or lower than the sink through hull and about 10 feet away, so teeing is out of the question. (I agree that the idea of using one through hull for more than one function is a bad idea. If I wanted to do that, I would build a manifold.)
San Souci is internally ballasted and has a very shallow bilge. She also has no life lines. Because of those two factors it is difficult to store more than 2 5 gallon water cans.
The bilge pumps sit in a sump that is about 30 inches below the floors and is about 2 feet square.
So, the easiest solution is to drill another hole in the hull and discharge the brine directly out of the boat.
The other solution I am considering is to direct the brine into the bilge sump where the bilge pump will pump it over the side.
Again, thanks for the comments, so far.

Norm

[john welsford]

Any reason why you cant run the discharge into the cockpit where it will then flow overboard through the drains?
John Welsford




Thanks for all of the responses.
We are planning some long distance cruising and only have tankage of 40 gallons of water. We are fairly frugal with our water usage, but would like to have more than absolute minimum.
As far as brine disposal is concerned, the problems are as follows:
The waste side of the water maker will be at or lower than the sink through hull and about 10 feet away, so teeing is out of the question. (I agree that the idea of using one through hull for more than one function is a bad idea. If I wanted to do that, I would build a manifold.)
San Souci is internally ballasted and has a very shallow bilge. She also has no life lines. Because of those two factors it is difficult to store more than 2 5 gallon water cans.
The bilge pumps sit in a sump that is about 30 inches below the floors and is about 2 feet square.
So, the easiest solution is to drill another hole in the hull and discharge the brine directly out of the boat.
The other solution I am considering is to direct the brine into the bilge sump where the bilge pump will pump it over the side.
Again, thanks for the comments, so far.

Norm

[donald branscom]

I have seen modern production sailboats 35 feet with as many as 14 through hulls!!! Crazy.
You make a sea chest, ONE THROUGH HULL and every thing branches off of that. ALSO it should come above the waterline inside the boat and have a raw water strainer. That way you can clean out the thru hull while the boat is in the water. Or work on the water pump on the engine without fear or a mess.

[nautiguy]

John, the cockpit presents the same problem as the sink drain, the slope runs the wrong way, so the brine would have to be pumped uphill.

Don, yeah, seachest, that's the word I was thinking of, not manifold. However, I think they are easier to engineer for intake rather than outflow, because most intake uses need a pump for lift, whereas most outflows are gravity fed.

Norm

[2MeterTroll]

save it and make salt.

[Tylerdurden]

It really depends on the water maker and the amount of reject it produces. Not all are the same. A swing check added to the sink would work fine.

[Cedric Rhyn]

A question, how much brine will you be producing and how quickly? If its not more than say a couple of gallons an hour for an hour or two a day, why not just run the hose into 5 gallon plastic jerrycan and when it gets a bit close to the top, carry it topsides and empty it?

Make sure you have a permit from the EPA though ( tongue in cheek)

Cedric



I think that I am going to install a small water maker soon, and I'm wondering what to do with the brine that is the waste product of the process.
Installing the water maker will require me to drill in a new through hull fitting for raw water intake, and I would like to not have to drill another hole in the hull. So, I am thinking of directing the discharge into to bilge pump sump. Besides not needing another through hull, it seems to me that the discharge will pickle the planking.
Any thoughts will be much appreciated.

Norm