Sink Outlet Position

[JimC]

Do forumites think the galley sink outlet seacock should be below or just above the waterline? On my present boat it is below the waterline and often becomes blocked by fatty deposits due to the outgoing dishwater being rapidly chilled as it nears the outlet. On my previous yacht (a Hunter Horizon 23) the outlet was just above the waterline and I never had this problem although (alarmingly in hindsight) there was no seacock fitted.

 

[sailorman]

ours is below the WL no real probs expert occasional potato peeling especially new pots.
the Avon Dinghy pump sorts that /forums/images/graemlins/cool.gif

 

[MoodySabre]

Below or a mark will build up down the gelcoat. Perhaps a less fatty diet might fix it!

Only joking - bacon butties are indispensable.

 

[l'escargot]

Just above, mine actually comes out through the boot topping. It stops it becoming blocked from outside, reduces the risk of flooding if the skin fitting fails and is close enough to the water surface for any staining not to be very apparent.

 

[PilotWolf]

I d suggest putting a u bend in it too... ours is just above the waterline and noisy when underway.

W.

 

[reeac]

Ours is below the waterline and as a result the drain pipe never drains completely - just down to the outside water level - and a dirty coating gradually builds up inside at that point. Maybe the answer - not cure - is to use opaque pipe.

 

[Guest]

Mines near enough waterline .... and needs a stopcock on it. If I heel towards the side sink is on ... water comes up the outlet enough to gurgle at plug-hole.
Also if FW tank is more than 1/2 full ... I get small flow of water through faucet on that tack ... so a stopcock is fitted in FW supply line ... but that's not th threads point.

I would suggest just above w/l is best ... but to be honest ... pouring hot fat down an average boat sink ? If you have outlet above w/l - that means that hot fat will exit and dribble down that wonderful gel-coat ....

 

[ShipsWoofy]

To be honest, I now understand why many countries are insisting on grey water tanks as well as black.

 

[Mirelle]

\"None of the above\" - this has worked for me for 15 years now

fit a sink with a 1.5" diameter waste, taken to a Whale diverter valve which also accesses bilge strum box the and thence to the bilge pump, thence overside via a U bend to a seacock.

One less hole in the hull, does not clog up, no risk of back flooding at any angle of heel.

The big diameter waste is a big advantage.

In fact no disadvantages that I can see.

 

[ShipsWoofy]

Re: \"None of the above\" - this has worked for me for 15 years now

[ QUOTE ]
In fact no disadvantages that I can see.

[/ QUOTE ]

First thing I would change if I bought your boat.

The amount of rubbish that can build up from the sink waste and you then compromise the output of the bilge pump, not only with a possible block in the pipe but all kinds of diverters and U-bends.

My bilge pumps are straight out the side, I understand monos need a gooseneck but IMHO that is all that should be between the pumps and the outside.

 

[Guest]

Re: \"None of the above\" - this has worked for me for 15 years now

My sink outlet is also connected to bilge pump ... so that when boat is moored ... I can open the outlet valve and allow my auto-bilge pump to discharge.... if anything there ... As I generally have dryish bilges and nothing to pump - I don't even have an over-ride or off switch on it..... just a fuse and connected.
The valve provides my security against water coming in when sailing etc. so not even a non-return valve - which IMHO are a waste of time ....
I don't get sink water draining to bilge with this either as bilge pump pipe is inverted U that takes it level to top of sink unit.
One outlet as Mirelle says and worked fine for years ....

Having had boat flooded in the past and all the mess etc. I certainly do not want a repeat ... so that is my answer to the problem.

 

[ShipsWoofy]

Re: \"None of the above\" - this has worked for me for 15 years now

I have had two 'in-line' none return valves fail on my bilge pumps.

I understand that many have systems that have worked for years, it is just a personal preference that my bilge outlets are 100% unhindered. Even though the electric pumps are there to collect and scoop up small amounts of water only, such as a dripping stern tube, left for a week a drip can add a lot of water (I learnt this from experience, before I fitted auto pumps). Or a toilet left with the switch in the wrong position, we were on board and heard the pump turning on and off as the boat moved. It was nice that the pump was keeping up without a problem.

My main hand pump drops straight out of the boat through a hole in the bridge-deck.

I was only suggesting that I personally would not plumb into an emergency pipe.

 

[Mirelle]

Re: \"None of the above\" - this has worked for me for 15 years now

There are of course two bilge pumps, in separate circuits (both manual, in my case; I have an "ideological objection" to electric bilge pumps!).

However, I suggest that a bilge pump that won't cope with washing up water is not to be relied on when used in good earnest!

What I did change, when I bought the boat, was a bilge pump that discharged into the self draining cockpit - that struck me as a really bad idea!

 

[Billjratt]

Re: \"None of the above\" - this has worked for me for 15 years now

Going back to the beginning - We don't put fat down the sink, SWMBO gives me guidance on how to empty the pan overboard. Our sink drains at the waterline and will fill back on port tack I think. The last boat certainly did, and it's outlet was well below the waterline. It's really a case of where the sink is in relation to the current air-water interface...