Kitchen sink outlet too low for gravity drainage

[Robbo]

Hi.

What are the options here? I thought poss small tank with whale gulper but not suitable?

Someone mentioned using a

Saniflow system with macerator?

Anyone else come up with this problem?

 

Thanks

 

I would just use the gulper, you don't need to use the plug then and if you get a timer device you just hit a button to empty the sink. You can get sink outlets that go to a 19mm hose so can directly attach to the gulper.

[DHutch]

We had this problem on Batavia (which sits very low in the water), and solved it using a Whale Gulper pump. This works fine, with a few provisos:

• It is probably best to have the pump below the level of the bottom of the sink - ours is about 300 mm below the sink.
• Have a length of hose (about 1.2 metres in our case) before the pump, so that if some idiot pours a small amount of boiling water down the sink, it doesn't immediately reach the pump. Having said that, we haven't had any problems with draining pans of vegetables, etc.
• Ensure that the waste from the sink to the pump has a high level vented connection - e.g. the sink's overflow. A friend had a sink (with no overflow) which used a Gulper pump and all was well until someone ran the pump with the plug in the sink. The pump pulled the plug well and truly home and much dismantling had to be done to remove the plug. In any case, you don't really need a plug, as once the hose to the pump is full of water, the sink won't drain until you run the pump.

Chris G

 

If you cannot have it above water, this sounds like good advice.

 

However it is always more simple to get it height enough. All out outlets are 10inchs from the waterline, except the kitchen sink, which is lower to remove the need for a pump of above standard worktop height. All sinks are plumbed strong hose, and even the kitchen sink manages around 4inchs.

 

The boat is around 2ft6 draft, with the floor around 6inches from the base plate.

 

 

 

Daniel

[Guest]

I wouldn't want one of those screw in skin fittings close to the waterline, personally. I have knocked more than one of these off. I would only have a welded in stub if close to the waterline, then a piece of hefty marine hose, double clipped as per DOR's post. That said I would avoid screw in skin fittings completely if ever I got another shell built.

I used to pass a little boat frequently that had a screw in skin fitting just about one inch above the waterline.

[BWM]

Hi.

What are the options here? I thought poss small tank with whale gulper but not suitable?

Someone mentioned using a

Saniflow system with macerator?

Anyone else come up with this problem?

 

Thanks

Whale supply a sump that is used in conjunction with a gulper pump. It has a built-in solid state switch which avoids having to turn the pump on manually. I had to fit one due to the sinks being at near water level. The only drawback I have found is the switch needs cleaning periodically due to a build up of soap, etc.

[blackrose]

I wouldn't want one of those screw in skin fittings close to the waterline, personally. I have knocked more than one of these off. I would only have a welded in stub if close to the waterline, then a piece of hefty marine hose, double clipped as per DOR's post. That said I would avoid screw in skin fittings completely if ever I got another shell built.

I used to pass a little boat frequently that had a screw in skin fitting just about one inch above the waterline.

 

What's a screw in skin fitting? The brass (or stainless) ones have a big backing washer and a nut on the back which screws on the inside.

 

I have fitted about 8 on my boat and never knocked a single one off. If it did happen it only really becomes a problem if they've been fitted too close to the waterline (or if you're on tidal waters with waves) and you don't realise it's happened..

 

And you end up with a "U" full of dirty, smelly, greasy water.

Not too bad for a liveaboard with the sink in daily use, but if a leisure boat, left for weeks between usage it can become unpleasant.

 

I don't follow either - you don't need U bends in sink waste pipes on boats.

Edited January 14, 2017 by blackrose

[WotEver]

I don't follow either - you don't need U bends in sink waste pipes on boats.

I believe Alan was describing a hose attached to the sink drain which exited at a skin fitting the same height as the bottom of the sink. The hose would always be full of water.

[blackrose]

I believe Alan was describing a hose attached to the sink drain which exited at a skin fitting the same height as the bottom of the sink. The hose would always be full of water.

 

Yes, if it's the same height as the bottom of the sink then after exiting the sink and fitting, then the waste pipe will curve slightly upwards and in effect it will form a U bend. The skin fitting needs to be slightly lower then the bottom of the sink's waste fitting so the pipe slopes down - but it only needs to be an inch lower with a shallow slope.

Edited January 14, 2017 by blackrose

[ditchcrawler]

I believe Alan was describing a hose attached to the sink drain which exited at a skin fitting the same height as the bottom of the sink. The hose would always be full of water.

The water in that would be no different to the water in a trap on a household sink and shouldn't smell any more.

[blackrose]

The water in that would be no different to the water in a trap on a household sink and shouldn't smell any more.

I think he meant for a non liveaboard where the waste-water sits there (in summer) for a while and isn't regularly rinsed away. Less likely on a boat or house that's occupied. But you're right, there are smelly sinks in houses too.

[ditchcrawler]

I think he meant for a non liveaboard where the waste-water sits there (in summer) for a while and isn't regularly rinsed away. Less likely on a boat or house that's occupied. But you're right, there are smelly sinks in houses too.

Its a good point, I have never noticed a smell at home when we get back after 6 or 8 weeks away, There has sometimes been a slight wiff from the shower drain on the boat as you can't drain that fully, but very little and I try to remember to give it a flush before leaving the boat. I wonder if anyone else has noticed any smell?

[Guest]

 

What's a screw in skin fitting? The brass (or stainless) ones have a big backing washer and a nut on the back which screws on the inside.

 

I have fitted about 8 on my boat and never knocked a single one off. If it did happen it only really becomes a problem if they've been fitted too close to the waterline (or if you're on tidal waters with waves) and you don't realise it's happened..

 

I don't follow either - you don't need U bends in sink waste pipes on boats.

Those are the ones I mean. Another on the "never again" list if I ever built another boat. I have knocked a couple off in narrow locks. Welede in spigots for me like my previpus boat. I DEFINITELY wouldn't entertain one near the waterline. Along with roof vents, brass diesel/water fillers and fender eyes, they are the work of the devil (my boat has all of these abominations.) I forgot rudder tubes that pass through diesel tanks.

Edited January 15, 2017 by Guest

[nb Innisfree]

On Innisfree I fitted bronze skin fittings (14 in total!) stronger and harder wearing than brass.

[Guest]

On Innisfree I fitted bronze skin fittings (14 in total!) stronger and harder wearing than brass.

Might give those a go if I knock another off.

I have often thought of trying to fashion some steel (stainless?) ones from bsp fittings with a bit of skullduggery, but yet another job I haven't got around to yet. I thought of using a threaded barrel nipple, with a locknut tack welded to the outside of the nipple. The locknut could be chamfered to avoid picking up on lock sides/pilings etc. Another locknut and washer on inside should do the trick.

Edited January 15, 2017 by Guest