Dirty Water Sump

[Jennifer McM]

This is no big deal.... YET!

 

We're our boat's 2nd owner, and it's the only boat we've experience of, though we've been continuously cruising her for almost 2 years.

 

Our dirty water from the kitchen and bathroom sinks, and the shower go into a sump that's obviously below water level. The water is automatically pumped up and out to get rid.

 

The only pain we have with the sump system is that every 6 weeks or so the whole lot has to come out (bathroom trim has to be dismantled), and a thick coating of yucky grease is removed. It's blinking awful job to do as you can imagine - maybe this is a 'normal' maintenance job boaters have to do? 

 

Sometimes dirty water gets backed up in the shower tray. When this happens the gulper is switched on to get rid of the dirty water, and the sump (and shower tray) gets a good cleaning. 

 

At times the drain in kitchen sink smelly, so a bit of melton steriliser is poured down the drain, and squirted into the overflow pipe.

 

We've looked in chandlers for something similar (or better), but can't find anything. 

 

It'll be sods law that the system will break down at an inconvenient time. So... I'd like to have a plan in mind, so the fix it can swing quickly into place.

 

The previous owner did say he made the system out of a kid's toybox.  We're wondering what is the system other boats have? 

 

Your thoughts will be much appreciated. ?

 

BTW as much grease as possible is removed with a sheet of kitchen paper towel before washing up.  

 

 

 

Edited July 25, 2018 by Jennifer McM

[rusty69]

Gravity feed kitchen sink (big bore pipe) 

 

Gulper directly connected to shower tray. 

[Jennifer McM]

9 minutes ago, rusty69 said:

Gravity feed kitchen sink (big bore pipe) 

 

Gulper directly connected to shower tray. 

 

Sorry Rusty, I mistook what you said.... you were talking of a solution, not asking a question.... 

 

 

 

 

Edited July 25, 2018 by Jennifer McM

[philjw]

The arrangement that you have is quite common for bathroom sink & shower wastes but not so much for the kitchen sink.  These are normally connected directly to a skin fitting since there is sufficient height over the water line. As rusty says use a big fitting with big bore pipe.  You will be able to continue the current arrangement for the bathroom as there will be no more grease.

[Jennifer McM]

2 minutes ago, philjw said:

The arrangement that you have is quite common for bathroom sink & shower wastes but not so much for the kitchen sink.  These are normally connected directly to a skin fitting since there is sufficient height over the water line. As rusty says use a big fitting with big bore pipe.  You will be able to continue the current arrangement for the bathroom as there will be no more grease.

That means punching a hole in the hull - a bigger job than I thought.

 

If we had this system, would the kitchen sink need a Gulper?

[rusty69]

2 minutes ago, Jennifer McM said:

Yes, all pipes are a gravity feed.

 

The Gulper is on the left gunnel on the first pic.

 

 

I reckon any sumpbox will get like that if fed with kitchen waste.

 

Our kitchen sink goes directly overboard, as does our bathroom waste. The shower waste is directly connected to the gulper. It does mean 3 skin fittings though, unless you can double one up with a y piece. 

 

You may be able to filter the kitchen waste before the sump, but suspect that would tgen need regular cleaning. 

[Jennifer McM]

1 minute ago, rusty69 said:

I reckon any sumpbox will get like that if fed with kitchen waste.

 

Our kitchen sink goes directly overboard, as does our bathroom waste. The shower waste is directly connected to the gulper. It does mean 3 skin fittings though, unless you can double one up with a y piece. 

 

You may be able to filter the kitchen waste before the sump, but suspect that would tgen need regular cleaning. 

That sounds like a plan! It'll need thinking out.

 

Thanks Rusty x

 

 

[rusty69]

8 minutes ago, Jennifer McM said:

 

Sorry Rusty, I mistook what you said.... you were talking of a solution, not asking a question.... 

 

 

 

 

Yep. No worries, i didn't word it very well. 

[BWM]

We have a whale sump and have to clean the automatic switch due to a build up of gunk, but generally this causes the pump to cycle every few minutes. Ordinary hand soap also causes the build Up, so diverting the kitchen sink may help but won't eliminate the problem. We have never had a blockage though, and I suspect yours is caused by the kink in the pipe that leaves the top of the tank, compounded by the suction of the pump. Find a way to remove the kink or replace the pipe.

[Jennifer McM]

29 minutes ago, BWM said:

We have a whale sump and have to clean the automatic switch due to a build up of gunk, but generally this causes the pump to cycle every few minutes. Ordinary hand soap also causes the build Up, so diverting the kitchen sink may help but won't eliminate the problem. We have never had a blockage though, and I suspect yours is caused by the kink in the pipe that leaves the top of the tank, compounded by the suction of the pump. Find a way to remove the kink or replace the pipe.

Thanks BMW, looks like the system is overdue a rethink. 

 

Thinking our boat surveyor should have picked up this 'unusual' system in his report 2 years ago, my OH remembered at the time the surveyor said couldn't get into the bathroom because the bathroom's sliding door was jammed. But on hindsight, I doubt it would have made a difference except to alert us to a 'problem'.

Edited July 25, 2018 by Jennifer McM

[David Mack]

I assume there is a float switch in the box which switches on the pump when the water gets to a certain height.  If the float switch or the pump fails, then the first you will know about it will be when the box overflows and you get smelly water on the floor and in the bilges. Its a disaster waiting to happen.

 

As others have said, I would pipe both kitchen and bathroom sinks straight out through the hull side, so they drain by gravity and are not affected by pump, float switch (or power) failure. Connect a hose from the shower tray outlet to the gulper inlet, and another from the gulper to a third skin fitting. If the length of hose between the shower tray and the pump is about twice that from the pump to the skin fitting (just coil up the excess length), then you won't get that annoying backflow from the waste fitting into the shower tray when the pump is switched off.

[Jennifer McM]

3 minutes ago, David Mack said:

I assume there is a float switch in the box which switches on the pump when the water gets to a certain height.  If the float switch or the pump fails, then the first you will know about it will be when the box overflows and you get smelly water on the floor and in the bilges. Its a disaster waiting to happen.

 

As others have said, I would pipe both kitchen and bathroom sinks straight out through the hull side, so they drain by gravity and are not affected by pump, float switch (or power) failure. Connect a hose from the shower tray outlet to the gulper inlet, and another from the gulper to a third skin fitting. If the length of hose between the shower tray and the pump is about twice that from the pump to the skin fitting (just coil up the excess length), then you won't get that annoying backflow from the waste fitting into the shower tray when the pump is switched off.

Thanks David, 

 

We've already got the gulper and the skin for the shower, so that'll be a more or less simple plumbing job for the shower.

 

For the kitchen and bathroom sinks, it'll be sensible to get a couple of holes made in the hull for gravity evacuation of water.

 

So now we're looking for the services of a boatyard.

 

We're making our way back through the Middle Levels, Nene, then the Grand Union.... onto Braunston (probably end of August), so wondering if anyone has a recommendation for a good boatyard?

 

Thanks everyone again 

[BEngo]

Fittings are a reasonably easy DIY job.

 

Screwfix sell wonderful holesaws www.screwfix.com/c/tools/holesaws/cat5920018?page_size=20#category=cat5920018&brand=bosch|starrett&page_size=20 which are just right for making the holes for skin fittings which can be had from the usual chandlers.  You will need a holesaw the right size for the fitting,  a bigger one for the lining and an arbor to put them on, and a decent drill- a new 18v cheapy cordless or even an older one of good make is fine.  Mark the centre of the hole with a bit of chalk.  If its on steel make  a starting centre in with a masonry nail and a nammer if you don't have the proper tool and drill the centre hole using just the holesaw arbor.  Go right through the lining.

 

 Otherwise if you can see on the inside lining where you want the hole then just drill the centre through the lining and then out through the hull. 

Next, use the large holesaw from the inside to get the lining and insulation out of the way and then the fitting-size holesaw from the outside. 

 

Whilst using the holesaw on steel keep squirting it with cutting compound or soapy water to keep things cool.  An assistant to squirt helps.

 

Fit the skin fitting, connect a big flex pipe between fitting and sink waste using jubilee clips at both ends and job done.  No need for fancy traps as you are not trying to keep the main sewer  smell out.

 

N

[Graham Davis]

It hasn't been said, but worthwhile pointing out, that you do not need to fit a U-bend between the sinks and the skin fitting, just go straight across. That gives you plenty of height above the waterline.

[Tony Brooks]

FWIW I cut a hole in my hull with a hole saw in an ordinary electric drill and fitted a skin fitting. A bit time consuming and plenty of cutting oil was needed. I did the same for my rinse fitting but that was in the gunwale. Skin fittings may not be ideal on a canal boat because they could get their flange knocked off or worn away in locks etc. but no sign of it after about 18years on. Drill powerd by a Honda Eu1000i so not a particularly powerful drill.

 

Edited to add - I made sure my skin fitting was brass, not some plastic stuff.

Edited July 25, 2018 by Tony Brooks

[rusty69]

27 minutes ago, Tony Brooks said:

FWIW I cut a hole in my hull with a hole saw in an ordinary electric drill and fitted a skin fitting

I have done this too, so if i can manage it, any idiot can. Just make sure you measure twice (no electrics, hull bracing, water pipes gas pipes, small furry animals  etc in the way) and cut once. 

 

Also above the water line is best

Edited July 25, 2018 by rusty69

[Jennifer McM]

42 minutes ago, BEngo said:

Fittings are a reasonably easy DIY job.

 

Screwfix sell wonderful holesaws www.screwfix.com/c/tools/holesaws/cat5920018?page_size=20#category=cat5920018&brand=bosch|starrett&page_size=20 which are just right for making the holes for skin fittings which can be had from the usual chandlers.  You will need a holesaw the right size for the fitting,  a bigger one for the lining and an arbor to put them on, and a decent drill- a new 18v cheapy cordless or even an older one of good make is fine.  Mark the centre of the hole with a bit of chalk.  If its on steel make  a starting centre in with a masonry nail and a nammer if you don't have the proper tool and drill the centre hole using just the holesaw arbor.  Go right through the lining.

 

 Otherwise if you can see on the inside lining where you want the hole then just drill the centre through the lining and then out through the hull. 

Next, use the large holesaw from the inside to get the lining and insulation out of the way and then the fitting-size holesaw from the outside. 

 

Whilst using the holesaw on steel keep squirting it with cutting compound or soapy water to keep things cool.  An assistant to squirt helps.

 

Fit the skin fitting, connect a big flex pipe between fitting and sink waste using jubilee clips at both ends and job done.  No need for fancy traps as you are not trying to keep the main sewer  smell out.

 

N

Many thanks for this, we're quite handy, but it does help to know what we're doing. You've explained it very well! 

 

Can't understand why the 'sump' was necessary in the first place. It's confused us no end.

 

Probably when we get to Braunston we'll get stuck in, as picking up bits and tools will be easier. Thanks again ?

39 minutes ago, Graham Davis said:

It hasn't been said, but worthwhile pointing out, that you do not need to fit a U-bend between the sinks and the skin fitting, just go straight across. That gives you plenty of height above the waterline.

Good point, thank you ?

39 minutes ago, Tony Brooks said:

FWIW I cut a hole in my hull with a hole saw in an ordinary electric drill and fitted a skin fitting. A bit time consuming and plenty of cutting oil was needed. I did the same for my rinse fitting but that was in the gunwale. Skin fittings may not be ideal on a canal boat because they could get their flange knocked off or worn away in locks etc. but no sign of it after about 18years on. Drill powerd by a Honda Eu1000i so not a particularly powerful drill.

Thank you, points to be aware of. Appreciate your help Tony ?

[Jennifer McM]

13 minutes ago, rusty69 said:

I have done this too, so if i can manage it, any idiot can. Just make sure you measure twice (no electrics, hull bracing, water pipes gas pipes, small furry animals  etc in the way) and cut once. 

 

Also above the water line is best

Well if you said 'any idiot' can do it, I hope we don't prove you wrong! ?

 

Brilliant tip about making the hole above the waterline.... ?

[rusty69]

Just now, Jennifer McM said:

Brilliant tip about making the hole above the waterline.... ?

Well, you know, just pointing out my years of experience of being around boats (usually best to keep the water on the outside) 

[philjw]

1 minute ago, Jennifer McM said:

Brilliant tip about making the hole above the waterline..

Don't worry too much about the closeness off the fitting to the waterline and the BSS. Because the drain hose come up to a high level this is OK. I think the BSS says 10 cm above waterline but check that.

[Jennifer McM]

1 minute ago, philjw said:

Don't worry too much about the closeness off the fitting to the waterline and the BSS. Because the drain hose come up to a high level this is OK. I think the BSS says 10 cm above waterline but check that.

Yes, good point, will check. Thanks ?

[rusty69]

12 minutes ago, philjw said:

Don't worry too much about the closeness off the fitting to the waterline and the BSS. Because the drain hose come up to a high level this is OK. I think the BSS says 10 cm above waterline but check that.

10 inches would be better 

[Tony Brooks]

18 minutes ago, philjw said:

Don't worry too much about the closeness off the fitting to the waterline and the BSS. Because the drain hose come up to a high level this is OK. I think the BSS says 10 cm above waterline but check that.

 

but its only advisory for private boats.

 

FWIW I drilled my hull hole from the inside out having first checked it was well above the waterline. That way you automatically stay clear of electrics, ribs & pipes. Not so eays of you can't get the lining out.

 

[blackrose]

2 hours ago, philjw said:

The arrangement that you have is quite common for bathroom sink & shower wastes but not so much for the kitchen sink.  These are normally connected directly to a skin fitting since there is sufficient height over the water line. As rusty says use a big fitting with big bore pipe.  You will be able to continue the current arrangement for the bathroom as there will be no more grease.

I don't really understand why bathroom sinks aren't as commonly gravity drained as kitchen sinks? Just there's there's a sump box or drain pump in the vicinity of the bathroom sink I guess so people tend to use it.

 

Both my sinks are gravity drained.

9 minutes ago, rusty69 said:

10 inches would be better 

And is the advisory, not 10cm

23 minutes ago, philjw said:

Don't worry too much about the closeness off the fitting to the waterline and the BSS. Because the drain hose come up to a high level this is OK. I think the BSS says 10 cm above waterline but check that.

Personally I would still want it as high as possible. If a brass skin fitting is fitted they can get damaged in locks, etc and then you've just got a hole in the hull and you wouldn't want that close to the waterline. The other option is to get a pipe welded in flush but they're subject to corrosion.

[philjw]

2 minutes ago, blackrose said:

I don't really understand why bathroom sinks aren't as commonly gravity drained as kitchen sinks? Just there's there's a sump box or drain pump in the vicinity of the bathroom sink I guess so people tend to use it.

My guess is that since it is always necessary to pump the shower, fitters avoid extra skin fittings by using a sump box and joining in the washbasin drain.