Sink outlet skin fitting

[DavidGrieves]

I'm re-fitting the galley area and want to fit a s/steel sink. The problem I have is I have little freeboard in my folkboat and the bottom of the sink is only about 3 inch above the water line. If I use a bronze skin fitting/sea cock/non-return valve would this be a sound sea worthy solution or should I just continue to throw the dish water over the side???
Does anybody have the waste water going to a skin fitting below the water line?
Anybody got any ideas/solutions???

Thanks in advance

Dave.

 

[Chris_Stannard]

I would suggest that if you have room fit a foot pump to the sink outlet, then you can keep the outlet above the waterline, and the pump should act as a non return valve, although you should still have a seacock on the outlet which should be closed when the sink is not in use at sea.

Chris Stannard

 

[Col]

Don't do it!
When boat is heeling over, you will get flooding as soon as rim of sink is lower than water level -Regardless of whether skin fitting is 3 inches, or 3 foot below sink.
Pump is far better arrangement. What about adapting a shower pump??

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[Twister_Ken]

David, I have almost exactly the same situation on the Twister- resolved by putting an in-line pump in the drain hose, wired to a manual bilge pump switch which is fitted in the galley wordwork. I replaced the pump with an identical model early this seaon, but can't remeber the model. If it helps it is cylindrical, blue plastic, with white endcaps, and maybe 4 inches long, inch and a bit in dia. It's from one of the main pump names, but I can't remember which. It pumps out through a Blakes seacock. I've had no back-flow through the system when the boat is well heeled.

A couple of words of warning. The pump is not designed to run dry for more than a few seconds, so make sure the switch is in a place where it can't be turned on accidentally (that's why I had to replace it!). Don't try to pump out when the seacock is closed. It pressures the outlet hose and could lead to unfortunate results - in my case the grease that seals the taper valve on the seacock was forced out, allowing water to seep into the under galley area. Easily fixed with fresh grease, but stupid.

 

[vyv_cox]

My galley and heads sinks both drain to below the water line, but my boat has more freeboard than yours. Can't see a problem if you are prepared to open/close the seacock each time you use it. I doubt if a check valve will allow the inevitable solids to pass through, rice grains in particular have an amazing ability to clog things up.

 

[Miker]

Thanks for that info. I was starting to get worried as my sink outlets also are below the water line. I try to ensure that the seacocks are shut when sailing.
The only problem I had was with the toilet which is much lower and have now fitted syphon loops in case the seacock is left open.

 

[Guest]

To prevent backflow on the sink waste you could try using a HepVo trap made by Hepworth Plumbing Products. It uses a "joker valve" to stop the back flow (glooping!) 1.25" size is adequete for most boats.

I've used these on my last two boats, and very sucessful they were too. Admitedly, they worked better with a 1" seacock rather than .5". The .5" needs tickling with a thin screwdriver to make it work properly.

The traps are easily available from any decent plumber's merchant. Ie: NOT B&Q! and much cheaper than a dedicated bilge pump.

 

[Avocet]

my sink outlet is above the waterline (about 2") and the bottom of my sink is about 4" above that. I have a very long pipe run but the sink still empties OK if a little slowly. I have a ball valve seacock in the line which I only close when leaving the boat. Even when very well heeled, the water doesn't come back up because the sink is quite near the centreline of the boat so it moves upwards as the boat heels.

 

[Avocet]

my sink outlet is above the waterline (about 2") and the bottom of my sink is about 4" above that. I have a very long pipe run but the sink still empties OK if a little slowly. I have a ball valve seacock in the line which I only close when leaving the boat. Even when very well heeled, the water doesn't come back up because the sink is quite near the centreline of the boat so it moves upwards as the boat heels.

 

[DavidGrieves]

Many thanks to you all.

David

 

[dickh]

On my Jaguar 27, my waste water outlet is below the water line, a bronze ¾" fitting with a Ball Valve on top for closing off. I have never had water gurgling up into the sink, that I know of, and because access is difficult the ball valve is left open all the time. Never had any trouble with it - in fact I renewed it 2 years ago as I was concerned wether the fitting was OK. It was, but I completely ruined in removing it so had to fit a new one. Does give peace of mind though knowing it has been renewed.

dickh
I'd rather be sailing... /forums/images/icons/smile.gif