Question, what all do I need for a raw water washdown?

ric · **Posted:** Thu Feb 09, 2012 9:11 pm

This spring I want to install a washdown system. What is all needed to bring to a mechanic to install that I would have to bring to them? Can anyone point me to the parts? As far as the hose connection on the hull goes where the hose screws on, I've mostly just seen cheap black plastic things. Is there a nicer metal one out there?

TX H210SS · **Joined:** Thu May 27, 2010 9:10 am **Posts:** 1488

I don't know for sure but have wondered if you were to splice into the hose line that leads to the impeller on the VP models if u could put a suction oump on it along with valve to and suck water through power unit. Couldn't use with motor running and would need vqlve to divert water flow but seems simple and no hull drilling.

ric · **Posted:** Fri Feb 10, 2012 12:16 am

TX H210SS wrote:

I don't know for sure but have wondered if you were to splice into the hose line that leads to the impeller on the VP models if u could put a suction oump on it along with valve to and suck water through power unit. Couldn't use with motor running and would need vqlve to divert water flow but seems simple and no hull drilling.

That would be genius. Just T the rubber hose going to the pump. I'm stealing that idea!!

chrisvs · **Posted:** Fri Feb 10, 2012 7:57 am

Ric, whatever way you decide to get your water feed, if you can install a stereo in your boat, I would think you don't need a mechanic to instal a washdown system. Pretty basic job.

chrisvs · **Posted:** Fri Feb 10, 2012 8:05 am

Oh, and as for the fittings....

http://www.jamestowndistributors.com/userportal/show_product.do?pid=15103&familyName=316+Stainless+Thru-Hull+Fittings+with+Hose+Barb+Connectors

And a washdown system... (with an install video to boot!)

http://www.jamestowndistributors.com/userportal/show_product.do?pid=57047&familyName=Jabsco+Par-Max+4.0+Washdown+Pump+Kit

ric · **Posted:** Fri Feb 10, 2012 9:40 am

would it be okay to T into the raw water engine pickup?

Does the washdown pump have a 1 way valve in it to prevent the engine pump from sucking vacuum through it? Or where could I buy one?

I'll just keep the hose below deck under the rear port jumpseat next to the outdrive lift pump. I could install this with zero holes in the boat except the screws to bolt down the pump and it will be totally hidden unless needed. Well it is needed, I scrub the deck at least twice a week and tired of using a bucket. It's really hard keeping a white boat.. white.

Borchik · **Posted:** Fri Feb 10, 2012 9:43 am

I would not suggest tapping into your water inlet line, would add places for leaks and air. You can buy a complete washdown kit that has everything included except the thru-hull fitting. I have installed several of them, takes about an hour from start to finish.

ric · **Posted:** Fri Feb 10, 2012 9:54 am

I could install a 1-way valve on the hose to the washdown pump, there's quite a few on the market like this:
http://www.iboats.com/Whale-Bilge-Acces ... w_id.47347

That way the engine raw water pump has no possibility of creating a vacuum and getting air through the washdown pump.

Like this

Paul I. · **Posted:** Fri Feb 10, 2012 10:30 am

I would not tap into the engine raw water. You would be adding three more connection that could fail or even more depending on how its done. As someone has already said "air", it could get trapped in the hose. In your diagram, you have no shut off at the juction point, with out one, if something failed.........

I would add a thru hull that is threaded and add a shut off valve. So the valve is threaded on to the thru hull fitting!And add a small backer plate too. Than go from there with hose &.........

chrisvs · **Posted:** Fri Feb 10, 2012 10:50 am

I agree with the others, I don't get a good feeling about tying into the raw water inlet either. A check valve might not work as there might be some pressure in the raw water line from the water traveling through the system when the boat is on plane. I just am not sure of what the flow would be doing.... is the raw pump sucking water faster than the "ram effect" of the water coming up the pickup? I wouldn't want to be the one testing the theory.

Like PaulI said, I think a thru hull, with a proper ball valve shut-off would be best.

ric · **Posted:** Fri Feb 10, 2012 11:29 am

There will be suction pressure acting on the check valve when the engine is running keeping it sealed shut, a proper check valve can handle this for the life of the boat. There's one on your car that controls your brakes. Without it and it controlling one way vacuum, you wouldn't have power brakes and it's just a little plastic thing. The wash down wouldn't be used with the engine running. There would be no air introduced into the cooling system as there is no vent to the atmosphere. A metal T would never burst or leak on the raw water suction pipe as it's only working on very little vacuum pressure and you use equipment all rated for this type of use. If you're worried about clamps, use T-bolt clamps. They don't loosen or break.

Having a hole in the boat since it's docked 24x7x365 is a concern. Flipping the valve on and off isn't something I want to do to squirt the hose for 10 seconds.

Paul I. · **Posted:** Fri Feb 10, 2012 1:54 pm

Lets see, some of us have 1 to 2 thru hulls with no problems. I have one for my head, some have 2 or 3 for the genset, head & raw water pick for those bigger boats with out outdrive.

You should have at least 2 bilged pumps on board anyways. What happens as I mention if one of the connections fails. At least with the thru hull, you can turn the valve off. I would rather depend on the valve & thru hull, than 3 or 4 hose connections & clamps. Lets ask this question, how many of us have "thru the hull transduces" and how many times have they leaked?? More so, something fails, your not getting home!!

Also, every time you want to use your washdown you need to remember that you can't with the engine running. You will need to inform everyone on board of this too.

chrisvs · **Posted:** Fri Feb 10, 2012 1:56 pm

I wouldn't rely on a simple unloaded "ball" check valve to seal against suction. I don't think there will be enough head (if any depending on where your pump is mounted) to give it a good seat. I would want a check valve that is spring loaded with a decent crack rating to seat against vacum. That might cause the wash pump trouble when it comes to priming & feeding itself.

Just remember, if you do this, and you mount your pump close to or below the waterline, you in effect have no shut off valve either, relying on a check valve that might not have enough seating pressure, and the vaines of the pump as a water seal. That's evern scarier IMO than putting the hole in the boat!

Paul I. · **Posted:** Fri Feb 10, 2012 3:17 pm

chrisvs, good point. I was thinking that the pump would be above te water line.

Borchik · **Posted:** Fri Feb 10, 2012 5:52 pm

You must also remember that every thing you do in relation to fuel, electric and water related, meaning stuff to keep your boat from sinking, has to be something that would meet USCG safety standards. As someone who has been working on boats since 16 years old I can tell you that I have never seen a check valve that would meet such standards. That does not mean there is not something out there but nothing I have ever seen. Being water inlets for engines are such large hoses I do not believe that anyone inspecting the boat for safety would approve of tapping into the inlet line for such use.

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Question, what all do I need for a raw water washdown?

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