Add Raw Water Washdown / Use Existing Seacock & Strainer?

[bajturner]

Looking for some advice. I want to add a raw water washdown and was thinking that instead of drilling a new hole in the bottom of the boat and adding another seacock, I would T off an existing seacock, likely the air conditioner raw water intake. I was thinking it would be easiest to add the T after the strainer to make use of it as well.

Are there reasons to not do this? Am I likely to run into any priming or air lock problems? I don't necessarily need to draw water for the washdown while the air conditioner is drawing water, but if I did, am I likely to ruin into any flow rate issues?

I have been thinking it though and my first pass is that the answers to the above questions are all no and there would be no problem. Any other thoughts? Anyone done this before? Am I missing something?

I am also considering adding a selector valve for the toilet such that it could be flushed either with raw water, or fresh water from the holding tank. I think half our fresh water currently goes to flushing the darn toilet! We are always in fresh water so there is no issue with salt water in the toilet. Good idea or no...any downsides to this?


Thanks!

 

[bajturner]

60+ views but no opinions...anyone with any thoughts on this?

 

[jason78]

Some boats are set up to pull from the lake to flush the toilets. I had a couple friends who had boats set up like this and they did not like always having lake water in the bowl. They both thought it caused the bathroom to stink when it had been sitting for the week and I think one said it caused the bowl to stain or need cleaning often. I have never had a boat that did not use freshwater.

 

[Henry Boyd]

I don't have any experience with non salt raw water use for the head, but have had quite a bit with salt. My feeling is that both would result in the same conditions, although the non salt would probably be less so. When you take on "fresh water" it has either been cleaned by a water processing plant, or comes from a well that someone is monitoring for cleanliness. Even a pristine lake has life in it. While a strainer will keep the fish out, it won't stop microbes and algae. If you get an algae bloom in your holding tank you won't believe the mess it will be to clean the tank out.

Henry

 

[sdarc]

Does your waste system have an overboard set up? If so I would look to using that instead being probably can't/shouldn't dump raw waste overboard on a lake. If tee'd off the AC I wouldn't run both at the same time. Just me.

 

[JimG]

When I told my dealer I wanted a lake water wash down, they recommended a separate seacock, which is what they did... so I don't know.

I agree with the others here on the fresh water head.

 

[moparlvr4406]

Having a raw water head..I wouldn't tee into it
the toilet is always nasty on the first few flushes especially in the slip..looks like mud water
after a few flushes it does clear out but there would be enough debris in our water to clog a hose nozzel real quick.
edit...first said freshwater..and it definitely is not

 

[HUMPH]

My friend with a 2007 310DA added a tee off of the AC pump for an anchor wash down. He has a switch at the dash and a nozzle pointed at the chain so he can wash it down as he pulls the anchor. Works great. I would not consider another thru hull for this personally.

 

[moparlvr4406]

My friend with a 2007 310DA added a tee off of the AC pump for an anchor wash down. He has a switch at the dash and a nozzle pointed at the chain so he can wash it down as he pulls the anchor. Works great. I would not consider another thru hull for this personally.

now THAT is a cool idea :thumbsup:

 

[twomad]

I used a t off the seacock for my head for my a/c that i installed never had any problems even when using both at the same time. Also never had a problem with using freshwater for my head. I have seen some boats that use freshwater tank for there head and they are constantly refilling it. Pia imo.

 

[Lazy Daze]

As far as being able to use raw (lake water) water for the head, there's just too many variables to say it's OK to use it. As noted above, it can often cause more smell simply because of the microbes in the water. But all lakes are different. Also, everybody has a different opinion on what chemicals to use and how often to pump out. All of this plays a factor in whether it will work to your satisfaction - what works for one person may not work for another. The only safe bet is to draw off your onboard water tank.

This will help with your onboard water usage: If it's yellow, let it mellow. If it's brown, flush it down.

As far as T-ing into your A/C intake and using it for a washdown - My initial thought would be that a washdown pump would draw most, if not all of the incoming water while it's being used. In short increments, I'm sure this wouldn't pose a problem. If it was being used constantly... I'm just not sure - I'm only going off a theory as I've never done it. I suppose if you figured out the GPM that the thru-hull would allow, then compare to what each component draws... But, again, just talking outloud here.

A head draws a very small amount of water - I'm sure that would never cause an issue with the A/C.

 

[bajturner]

My friend with a 2007 310DA added a tee off of the AC pump for an anchor wash down. He has a switch at the dash and a nozzle pointed at the chain so he can wash it down as he pulls the anchor. Works great. I would not consider another thru hull for this personally.

So he put a tee downstream of the pump and did not add a dedicated washdown pump? My plan was to put the tee between the strainer and the AC pump and add a new pump just for the washdown.

Your friend's setup is very cool!

 

[bajturner]

Does your waste system have an overboard set up? If so I would look to using that instead being probably can't/shouldn't dump raw waste overboard on a lake.

It does have overboard discharge, but as you suspected, it cannot be used. It is illegal here and the discharge seacock has to be locked closed.

 

[bajturner]

If you get an algae bloom in your holding tank you won't believe the mess it will be to clean the tank out.

Never thought of an algae bloom in the tank...what typical toilet chemicals prevent that?

 

[bajturner]

They both thought it caused the bathroom to stink when it had been sitting for the week and I think one said it caused the bowl to stain or need cleaning often.

I suppose if I had a selector valve, I could use raw water (which will always be fresh lake water) and then at the end of the weekend switch to potable water from the tank and flush a few times before leaving.

I could also only use the raw water option if the holding tank was starting to run low and I wasn't going to have the ability to refill...

 

[sdarc]

It does have overboard discharge, but as you suspected, it cannot be used. It is illegal here and the discharge seacock has to be locked closed.

My thought was to seal off coming from the holding tank and attach a pump to that thru hull.

 

[ttmott]

To interconnect the raw and potable water either by valving or a tee would be not in compliance to both the NSF and AYBC. In order to be compliant and have an interface the potable side must operate at a higher standard pressure and have an anti-siphon / backflow device. I spend a lot of time and effort ensuring clean pure water in the fresh water system and wouldn't want to take any chances.