Selectable Washdown Setup (Fresh/Raw water)

[wrwakefield]

Thanks, Kenbo,

A safety check valve on the potible water side is a very valid detail to highlight.

In our case, a check valve is installed [after a shut off valve] to an isolated fresh water manifold feeding numerous consumer circuits. e.g., washdown pump via the 3-way valve, two heads, the engine raw water backflush and emergency raw water coolant feed to the engine and generator, and a potable water washdown hose in the engine room. [i.e., All circuits that could contaminate potable water via back-siphoning are isolated on a separate manifold from the main potable circuits feeding the sinks and showers.]

This design is simpler to implement than write about.

There is another check valve on the outfeed from the potable pump as a back-up.

Thanks again for making sure this is well understood.

Cheers! Bill

[Waypoint]

I bought an adaptor that enables me to connect a garden hose to the bathroom tap just poke the hose up thruough the hatch and wash away

[DeepCut]

Sailor 1924

What brand pressure washer do you have?

[jkleins]

We had a fresh water washdown on our boat when we bought it. We added a salt water throughhull and pump and just teed it into the line with a three way valve just before the deck fitting. We keep it turned to salt water until we want a fresh rinse and then turn it to fresh and use it from the pressurized fresh water system.
I don’t see anyway that salt water is going to get into a pressurized fresh system unless it is pressurized itself. We just keep the salt water pump off until we need it so it is never pressurized.
If you did happen to turn the valve when there was a little bit of pressure the blow back would be flushed out as soon as you turn the nozzle on to spray the fresh water.
I think the idea of the check valve is fine but overkill for your use.
If for some reason you wanted to have both systems pressurized all the time it might make sense to have some protection from a valve failure but if you just depressurize the salt water side water can only flow out from the fresh side if there is a problem which shouldn’t be an issue.

Jim

[Pelagic]

Originally Posted by stormalong

I do not think you realize how quickly you will deplete your water maker water by rinsing your deck with it. The energy and time needed to produce RO water makes it very expensive. Are you sure you really want to do this?

Very good point, but there are ways to manage FW consumption and educate crew/guests at same time.

Our RO product Test line has a long hose that runs up and out an ER vent, so that it is hidden but can easily be pulled out on deck.

Once product passes taste test (I never trust sensors) the first part is used to fill a large garbage bucket, while the RO settles down to best quality, then a final taste test before switching to tank.

That large bucket of water is used to rinse off the salt via a small bucket and cloth, starting with the cockpit and all the areas we touch......
.....Or used for laundry.

When guests see how long it takes to fill that garbage bucket from tiny product line, they become much better at conserving.

Another "management" consideration is to make sure you can run your water maker whenever motor sailing so that your tank is always full along with your batteries.

For those like me who have a large output RO (about 800g/day making sure your invertor can handle the 3/4 HP pump is part of it. (Or switch to DC motor for high pressure pump)

Nice to know you have that ability when gunk holing along a remote coast against headwinds to rinse off at each night anchorage.

From a health perspective, making your own water in the Tropics is worth the expense as you never know the quality of shore side supply.

Having a clean cockpit at night, is another standard, I just won't compromise on.

[ErBrown]

Thanks folks, we're been talking through options and are thinking we'll likely hold-off on a dedicated Fresh Water wash down. We'll start with a simple option (several post here mentioned as well) of rinsing the deck with our existing Raw Water wash down and then a final fresh water rinse from a bucket/brush.

We do have a pressurized house system (pressure vessel and 12v belt driven pump). That system currently feeds our cockpit shower and we kicked around the idea of tapping into this for a deck rinse, but I'm not sure I want to tax the house system this hard. Might explore this down the road though, depending on how workable we find our current plan. Trying to avoid adding more gear to the boat unless we actually think it's needed or at least...will be useful.

Thanks again for all the feedback,
Erin

[daletournier]

Originally Posted by stormalong

I do not think you realize how quickly you will deplete your water maker water by rinsing your deck with it. The energy and time needed to produce RO water makes it very expensive. Are you sure you really want to do this?

It depends on watermaker size. I wash mine down once per week if we haven't had rain. The water maker is 140l/hr, 1/2 run time usually covers my washing boat down water.

[kapnkarl]

Any chance you could diagram the setup you have. Plumbing & check valves are definitely not my strength.

[sailor1924]

Originally Posted by DeepCut

Sailor 1924

What brand pressure washer do you have?

It's a Karcher 1200 psi. I have a 5 gal bucket into which I installed a hose bib and valve, as the limited fresh water supply, no pump needed for a quick rinse.

[ejjawhite]

Get rid of the salt water wash down since you have a water-maker, or follow previous advice and wash w salt water, then rinse w a few gallons of fresh. I’d run them on separate pumps and again, as previously stated, you’ll have a spare pump should you ever need it.

[ValiantV]

Originally Posted by ErBrown

This makes sense, and was my largest concern. Obviously we don't want to compromise drinking water for a convenience feature. That being said, I'm really not to excited about the idea of cutting another hole in the deck for a fresh water wash down.

Will have to see what else we can come up with.

As opposed to making more holes in your boat, is a connection to the existing fresh water system located in a lazarette or anchor locker an option? You could still install a "quick disconnect" as others have suggested, or, just a plain old "hose bibb" (with a better valve) and use a garden hose as you might when washing your boat at the dock or filling your fresh water tanks.

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