Plumbing question

Canuck · Post by **Canuck** » Thu Mar 09, 2006 12:58 pm

I plan to tee my head and galley sinks and possibly a shower sump pump into 1 common drain going to a 1" bronze seacock. My question : could I also draw water for my Lavac head intake from this same seacock if I put a tee close to the seacock ? Would the sink drains have to be plugged tight for it to work ? I will have a shut-off on the shower drain as it will be rarely used.
Thanks

Figment · Post by **Figment** » Thu Mar 09, 2006 1:16 pm

I don't see any reason why it shouldn't work, so long as the tee is below the waterline. The (assumed) extra hose run length might mean you need a few extra pumps to get a full flush, but that's no tragedy.

I suppose there is some element of risk in having an additional connection (which could someday fail and sink the boat) below the waterline, but I don't suppose that the risk is any greater than if the head had its own dedicated intake. The argument could be made either way.

Summersdawn · Post by **Summersdawn** » Thu Mar 09, 2006 1:45 pm

could I also draw water for my Lavac head intake from this same seacock if I put a tee close to the seacock ?

I don't think this will work. You can't draw water from the same opening as you discharge. What would happen is your discharge would just get recirculated.

Post by **Tim** » Thu Mar 09, 2006 3:15 pm

I'm all for minimizing the number of openings in the hull, but to me it never seems like good practice to use a discharge also as an intake. I'd rather see intakes combined into a single larger fitting, or discharges combined, but ne'er the two shall meet, in my opinion.

A30_John · Post by **A30_John** » Thu Mar 09, 2006 9:01 pm

I plan to tee my head and galley sinks and possibly a shower sump pump into 1 common drain going to a 1" bronze seacock. My question : could I also draw water for my Lavac head intake from this same seacock if I put a tee close to the seacock ?

Canuck, I would be extremely cautious about doing this. First, I don't see how it could work without recirculating waste through the head. That should be avoided. (Imagine hanging over the bowl when you're seasick-a clean bowl would be more inviting. You get sick. Thinking it's all over, you flush. And, then, feeling sick again, you open the lid to continue and what are you faced with...) Second, I personally would not want the head waste anywhere near my galley sink. If you use the head when you're at sea, the seacock is open, and everything is gurgling and burbling away down there, there could be a little back siphoning into your galley sink, yuk, this is where dishes are washed, teeth brushed etc. then possible splashing on your food preparation areas. Perhaps I'm overly cautious here, but a few germs can unsuspectingly turn into a serious safety issue.

Also check the size of the seacock for your head outlet. I think the Lavac specifies 1.5".

BTW, if you're looking for further information on the recommended installation for the Lavac head, the user manual can be downloaded online here:

http://www.blakes-lavac-taylors.co.uk/prod03.htm

You've done a wonderful job on your hull. I'm looking forward to seeing more pictures!

Figment · Post by **Figment** » Fri Mar 10, 2006 8:58 am

I had interpreted the first post to mean that the discharge for the head's SINK, the galley sink, and shower sump were being ganged, and that the head TOILET would draw (potentially) "grey water" from this line for flushing.

Ric in Richmond · Post by **Ric in Richmond** » Fri Mar 10, 2006 9:19 am

"I am going to plumb my head intake and head drain and sink drain all onto the same thru hull"

Did I read that right?

That has to be a recipe for disaster.

Scenario 1-

Lets say a critter takes up residence in the thru hull. Then you go to "dump" over board and it is blocked. Where does the water go? Up into the sink...the same sink you wash dishes in.

Scenario 2-

You recirculate a bunch of the "old" water into the "new" intake water (which doesn't get flushed all the way thru the line) and the "new" water sits in the intake line...for a week or three while you aren't using the boat. That ferments into a primordial oozes that permeates any line you could possibly devise leaving a smell that will wake the dead.

Scenario 3-

You sink is slightly off the center line and back fills when you heel on one tack. Some of the things you have pumped into your drain line drain line "float" and they "float" to the top of the water column and into your sink.

I am all for minimizing thru hulls, but read that again and tell me you think that is a good idea.

I'd say there will be vomiting on board and it won't be from motion sickness....

A30_John · Post by **A30_John** » Fri Mar 10, 2006 9:54 am

I had interpreted the first post to mean that the discharge for the head's SINK, the galley sink, and shower sump were being ganged, and that the head TOILET would draw (potentially) "grey water" from this line for flushing.

That sounds like a more palatable alternative. I guess it's all in the interpretation..

Canuck · Post by **Canuck** » Fri Mar 10, 2006 12:17 pm

Thanks everyone for your input. To clarify: I am only talking about the 3/4" intake to the head. I will certainly not have the head outlet near any other through hulls. As far as some soapy grey water being drawn into the head inlet, I don't see how that could be a problem. Also, it would be very unlikely that someone would be draining a sink at the same time that someone else is flushing the toilet. With everthing static there should only be clean seawater sitting in that line when water is being drawn into the head.
I read somewhere that some production boat builders do this, which is where I got the idea.
Thanks again.
Ernie

Post by **Tim** » Fri Mar 10, 2006 1:13 pm

Canuck wrote:I read somewhere that some production boat builders do this, which is where I got the idea.

Well, production boatbuilders do a lot of things in the interest of saving time and money--it doesn't mean it's the "best" way. One of the beauties of building a custom or semi-custon boat (or rebuilding an old boat) is the opportunity to do better than production boatbuilders.

While I still prefer keeping intakes as intakes and discharges as discharges, you can certainly tee your head intake into the drains for sinks if this makes sense in your situation.

catamount · Post by **catamount** » Fri Mar 10, 2006 1:29 pm

I have heard of this idea before somewhere else (think...was this in the Head Mistress's book about eliminating boat odors?).

I don't really see anything wrong with recycling the greywater from your sink and shower drains through your head. Some have argued that there is in fact a benefit, as presumably you would be periodically flushing fresh water through the head plumbing.

Regards,

Ric in Richmond · Post by **Ric in Richmond** » Fri Mar 10, 2006 6:47 pm

My bad....I read "plumb head and galley sinks" instead of "head (sink) and galley sink".

I thought you had lost it! And here it was my reading it all wrong!!.

I agree now.

SINK discharges and toilet intake are probably fine.

Summersdawn · Post by **Summersdawn** » Fri Mar 10, 2006 7:19 pm

I misread it too. I can see the logic behind drawing your head intake from the sink outlet, however, I would probably keep them seperate myself, but that is just my opinion.

A30_John · Post by **A30_John** » Fri Mar 10, 2006 10:16 pm

Now that that little scare is over, check this out folks! The stork left this little beauty on my doorstep his afternoon. That's right, a shiny new Lavac Popular.

bcooke · Post by **bcooke** » Fri Mar 10, 2006 10:45 pm

Hey!!! That stork got our shipping addresses mixed up again!

-Britton

A30_John · Post by **A30_John** » Fri Mar 10, 2006 11:15 pm

Isn't it something?

Based on what I'm seeing regarding size, quality of construction, etc., I think this would be the one you want for your Triton, Britton.

bcooke · Post by **bcooke** » Sat Mar 11, 2006 12:15 am

As soon as the sale of my kidney goes through I will have one.

Figment · Post by **Figment** » Sat Mar 11, 2006 8:46 am

Ah, there's nothing like a head-related question to spark a nice fat multi-page thread!