Drain heads sink via wc

[alisdair4]

I am considering a fairly major reorganisation of the heads compartment in my Rival 32. I envisage moving the sink from directly opposite the WC (Jabsco) to behind and above it. The sink currently drains through its own through-hull and seacock. I don't want to have to fit another through-hull, and wondered if it would be possible to drain it via the WC, perhaps with divertor valve somewhere in the system.

Has anyone done this, and can they advise on the plumbing requirements.

Thanks in advance.

 

[TimBennet]

The sink drain is part of the 'grey' waste system and the heads outlet the 'black'.

It's generally preferable to keep them separate and diverter valves add no less complexity than a dedicated through-hull and valve.

 

[alisdair4]

The sink drain is part of the 'grey' waste system and the heads outlet the 'black'.

It's generally preferable to keep them separate and diverter valves add no less complexity than a dedicated through-hull and valve.

Hadn't considered the "grey/black" issue as particularly important, TBH. (Ie, it all goes into the oggin!) However, I am keen to avoid complexity, so may look at a dedicated through-hull. Thanks.

 

[Leighb]

On our boat the heads sink drains through the same skin fitting as the WC inlet, there is no diverter valve just a Y connector. This seems to work perfectly well. It also enables us to fill the system with fresh water when leaving the boat, although I am not entirely convinced that it makes any difference to the sulphur "pong".

 

[sailorman]

On our boat the heads sink drains through the same skin fitting as the WC inlet, there is no diverter valve just a Y connector. This seems to work perfectly well. It also enables us to fill the system with fresh water when leaving the boat, although I am not entirely convinced that it makes any difference to the sulphur "pong".

we have exactly the same via a diverter valve into the lavac

 

[TimBennet]

On our boat the heads sink drains through the same skin fitting as the WC inlet,

If yours works then so be it. You might be lucky, but when you pump the heads there will be a low pressure in the intake line that can suck air via the sink drain if that's the path of least resistance.

Back in the 70's and 80's when people still thought steel boats were a cool idea, we spent aged trying to minimise the number of through-hulls in the boats we built because they were seen as 'points' of weakness. But water chests, collector sumps, shared valves were all found to be complications that were rarely worth it when trying to 'simplify' the systems.

 

[BobnLesley]

Our Albin Vega had a slide-out washbasin which when out positioned the basin's waste out let directly over the jabsco toilet bowl and so discharged into it; I still think it was a marvellous bit of KISS design. As an added bonus (once we'd installed the holding tank) it allowed you to use the heads with a fresh-water flush even whilst dried out against a harbour wall.

If you're planning a fixed washbasin, it should be equally practical to have an 'open' flexible hose from the basin's outlet and a simple brackets/clips to hold it in place either over the toilet bowl when using the basin and out of the way when you want to sit on the heads.

 

[alisdair4]

What a super idea! I will see if a slliding basin as you described would work.

 

[Biggles Wader]

If yours works then so be it. You might be lucky, but when you pump the heads there will be a low pressure in the intake line that can suck air via the sink drain if that's the path of least resistance.

Back in the 70's and 80's when people still thought steel boats were a cool idea, we spent aged trying to minimise the number of through-hulls in the boats we built because they were seen as 'points' of weakness. But water chests, collector sumps, shared valves were all found to be complications that were rarely worth it when trying to 'simplify' the systems.

Im very old fashioned as I still think of through hulls as a point of weakness.If the boat is going to leak it will probably leak through somewhere associated with a hole through the hull so minimising them seems like a good idea.

 

[lw395]

One of my boats had the sink plumbed into the loo inlet pump, via a changeover valve.
So you pumped the sink empty via the loo.
It did mean you could pump some disinfectant or whatever through the loo, simply by pouring it into the sink.
IIRC the valve was made by Whale?

 

[TimBennet]

Im very old fashioned as I still think of through hulls as a point of weakness.If the boat is going to leak it will probably leak through somewhere associated with a hole through the hull so minimising them seems like a good idea.

There's nothing flawed or old fashioned in your logic. My point was simply that despite all the effort we made to eliminate these 'weak points', rarely did the benefits actually outweigh the problems we had.

 

[Biggles Wader]

There's nothing flawed or old fashioned in your logic. My point was simply that despite all the effort we made to eliminate these 'weak points', rarely did the benefits actually outweigh the problems we had.

Agreed.My ideal would be no sinks,bucket and chucket loo,and an outboard engine so no through hulls at all,but the benefits of a proper engine sink and loo are the reason we have them and put up with the bloody holes.

 

[lw395]

Im very old fashioned as I still think of through hulls as a point of weakness.If the boat is going to leak it will probably leak through somewhere associated with a hole through the hull so minimising them seems like a good idea.

From my experience through hull fittings are very reliable, most leaks come through windows. Secondly fittings on deck.
Yes all through hulls need to be beyond reproach, but it's not that difficult.

 

[Leighb]

If yours works then so be it. You might be lucky, but when you pump the heads there will be a low pressure in the intake line that can suck air via the sink drain if that's the path of least resistance.

The sink drain does make strange noises when you pump the heads, but it functions just fine, presumably the relative heights of sink, inlet and heads work out OK?

 

[sailorman]

One of my boats had the sink plumbed into the loo inlet pump, via a changeover valve.
So you pumped the sink empty via the loo.
It did mean you could pump some disinfectant or whatever through the loo, simply by pouring it into the sink.
IIRC the valve was made by Whale?

the very same as us.
also leave disinfectant in the sink waste pipe too

 

[alisdair4]

Thanks to all for the helpful comments and suggestions.

 

[dovekie]

We have the same arrangement as two have posted above. The sink drain is connected by a Y-diverter to the toilet inlet pump, so the toilet pump can flush with sink water or seawater. Works well for us, even with the sink on the opposite side of the boat to the toilet. And, it will still empty the sink even when the boat is too far heeled for drainage to do so.

 

[Suttle]

My R32 sink slides out and drains through the Lavac via a diverter valve. I thought most R32's had the sink sliding out.

 

[grumpy_o_g]

I've seen this recommended as a method of getting fresh water into the loo so you can do a final fresh water flush before leaving the boat. Mind you I've also seen it said you keep grey and black waste absolutely separate.