Fitting water maker using heads intake pipe!

[pcatterall]

Doesn't sound to great does it! The very best place I can see to site my water maker is up front and close to the Jabsco toilet intake pipe. I cannot see how contaminated water could get back into the water maker and am very reluctant to make a further hole in the boat! There is an issue when the boat has not been used for weeks when water trapped in the inlet pipe can get very smelly ( we re in the Med.) but flushing through will sort that.
If it seems ok to use that inlet then I will need an unequal Tee from the inlets pipe 3/4" to the water makers 3/8" I cannot locate that size so would appreciate a steer as to a good source.
Any advice appreciated

 

[burgundyben]

Use an equal tee and reducing bushes?

 

[superheat6k]

If your toilet pump is an up / down plunger like the common Jabsco bear in mind one side of the plunger is in the nasty and the other is the flush water, with connected hose back to the inlet. The bacteria causing the smell are at minimum being contributed to by the cross plunger bacteria.

If you are drawing near the sea inlet but not sharing the inlet then less of an issue, but stay well away from and forward of the pooh outlet port. Water in the toilet supply pipe should definitely be regarded as contaminated, IMHO.

 

[peter gibbs]

Weighing up another hole in the hull against the need to keep the freshwater intake distant from outfalls is in my book an easy one. Contamination is a serious concern, much more than than another hole in the hull.

Doing as you suggest would require valving to prevent any flashback when toilet water is being taken in, to keep the source uncontaminated.

But you might have been relying on the water maker to keep contamination impurities at bay? Are you satisfied with that strategy?

On resale your boat would certainly raise a ? on survey.....

PWG

 

[lustyd]

It's interesting. On the one hand superheat6k is right that the pipe is contaminated. On the other hand, if the watermaker works where's the problem? In theory the worst case is you'll clog up the membrane with extra grot and need more cleaning of the watermaker. On the other hand, if you're not really good at flushing out and regular use your watermaker will be where the nasties live and grow. Just the idea of that makes me think new pipe.

 

[pcatterall]

It's interesting. On the one hand superheat6k is right that the pipe is contaminated. On the other hand, if the watermaker works where's the problem? In theory the worst case is you'll clog up the membrane with extra grot and need more cleaning of the watermaker. On the other hand, if you're not really good at flushing out and regular use your watermaker will be where the nasties live and grow. Just the idea of that makes me think new pipe.

Thanks all, I dont want to rely on the water maker clearing toilet contamination, it would but as suggested, t the expense of extra cleaning or ruined membrane. Perhaps another then ! I guess it could be very small 3/8ths to suit the pipe. I had been thinking of a sea water tap any way!
Thanks all.

 

[Neeves]

You mention you are thinking of a seawater tap, I assume in the galley - excellent idea. There is nothing wrong with washing up (fresh rinse) nor washing veg using seawater. But surely you have a deck wash and or chain wash (or you have a very smelly chain/anchor locker). Being in the Med I'm surprised you don't have a transom shower. If you don't have a chain wash now, as your thinking of salt water at the galley, is a good time to think about it. You could feed galley, desal unit, transom showers and deck wash from one new inlet - just keep it ahead of the toilet discharge (and keep moving forward ). To be doubly sure have the new intake on the other side of the hull from the toilet discharge.

Jonathan

If you do instal and new intake think of adding a manifold at the same time so that you can add offtakes later.

 

[geem]

Doesn't sound to great does it! The very best place I can see to site my water maker is up front and close to the Jabsco toilet intake pipe. I cannot see how contaminated water could get back into the water maker and am very reluctant to make a further hole in the boat! There is an issue when the boat has not been used for weeks when water trapped in the inlet pipe can get very smelly ( we re in the Med.) but flushing through will sort that.
If it seems ok to use that inlet then I will need an unequal Tee from the inlets pipe 3/4" to the water makers 3/8" I cannot locate that size so would appreciate a steer as to a good source.
Any advice appreciated

Our boat uses a common seacock for the wash hand basin waste and toilet seawater intake. The benefit being that you can close the seacock then run fresh water in the wash hand basin to flush the toilet with fresh water. Great when you are leaving the boat for a few days. You have an opportunity to convert to this system then use the 3/4” wash hand basin redundant seacock for the watermaker inlet.

 

[Spirit (of Glenans)]

If you feel the need for a wayermaker you will also need seawater in the galley, in order to conserve the expensive H20. Use a common intake for both.

 

[dankilb]

If you feel the need for a wayermaker you will also need seawater in the galley, in order to conserve the expensive H20. Use a common intake for both.

This is interesting to me, as I recently glassed over our galley salt water tap intake. This isn’t to say I can’t/won’t re-instate it, but I hadn’t planned to. (all the galley skin fitting holes were glassed over as they’d been fitted without backing pads and subsequently molested such that it was easier to glass over the lot and start again, which will now happen after lockdown...).

Anyway, I was thinking we would do without yet another ‘hole in the boat’ for galley saltwater and just use a bucket, via Jerry can etc, if required. It wouldn’t be a good location for a manifold or plumbing to feed other services.

But this thread is making me think a new through hull and manifold opposite the forward heads might be worth fitting? We could use a deck/anchor wash and may fit a watermaker in the distant future.

 

[Moodysailor]

But this thread is making me think a new through hull and manifold opposite the forward heads might be worth fitting? We could use a deck/anchor wash and may fit a watermaker in the distant future.

I'm sure you have already considered this, but if installing another inlet opposite the heads, be very mindful of the location of the heads outlet. On our boat the inlet & outlet are on opposite sides of the keel to assist with 'separation' of the inlet and waste, as well as the obvious outlet being aft of the inlet.

Our deckwash inlet is located well fwd and clear of other fittings, i'm going to take the advice above and use the DW pump to feed galley seawater flush

 

[Neeves]

But this thread is making me think a new through hull and manifold opposite the forward heads might be worth fitting? We could use a deck/anchor wash and may fit a watermaker in the distant future.

It depends where you were thinking of fitting the through hull that might also be used for a water maker - but you want the water maker flow not to be interrupted in big seas by sucking in air. I stand to be corrected but for a variety of reasons you want the water maker intake (even if it is used for other applications) as low down as possible (no danger of sucking in spilt fuel from a neighbouring yacht (but its the air I was really thinking of). I'm assuming you might desal water when at sea.

Jonathan

A bit of drift - Spirit's comment on 'expensive' desal water is very valid - it uses lots of power so the idea you have limitless fresh water has caveats. We have a bucket in the shower and collect all the cold water before the hot water arrives at the shower head - its perfectly adequate for washing dishes. We religiously try to run the desal unit when an engine is running, entering/leaving an anchorage etc or when our trailing hydro gen is producing high amps when boat speed is good. Without a desal we would plan passages round water replenishment from a terrestrial tap, with a desal we are much more parsimonious and ignore taps.

 

[dankilb]

Thanks @Neeves and @Moodysailor - on reflection I doubt that opposite the heads would indeed be far enough away for watermaker (and it’s just forward of the keel too), but it would still work well for a deckwash and also galley feed.

I guess you can always ‘decommission’ the heads while desal is running? I did think this with the OP’s predicament: a simple option could be just to divert/shut off the heads inlet with a ‘changeover’ valve for the watermaker. Presumably one can do without flushing for a time, to guarantee no blackwater gets to the watermaker?

 

[dgadee]

Is the 'no extra hole in the hull' thinking so valid these days? I can imagine in wooden boats it was highly relevant, but in a well built hull with a good quality seacock have things changed? I certainly put in an extra seacock (marelon one) for my water maker. Didn't really think twice about it.

 

[dankilb]

Is the 'no extra hole in the hull' thinking so valid these days? I can imagine in wooden boats it was highly relevant, but in a well built hull with a good quality seacock have things changed? I certainly put in an extra seacock (marelon one) for my water maker. Didn't really think twice about it.

Yeah I guess not - or only insofar as it's one extra thing to think about, remember to close, etc. Certainly no issue for the hull itself - only for the seacock and its associated plumbing.

That said, there were a couple of factory through-hulls on our boat we were very happy to 'delete': The first was for the aft cabin 'vanity' sink drains - located under a berth, behind the engine, squeezed in between the bearers, shaft, and gearbox! (sinks since deleted too!) The second was for an 'auxiliary' bilge pump, at the bottom of a locker under the middle saloon/settee seat, right where heavy stuff would tend to land if thrown in there! (said pump now has a hose you can poke into the sink or out a portlight!)

 

[geem]

If you feel the need for a wayermaker you will also need seawater in the galley, in order to conserve the expensive H20. Use a common intake for both.

Not me. We dont want or need a salt water pump in the galley. I wouldnt want to use it in a busy anchorage where people use their sea toilet. By comparison our 200l/hr watermaker can be used quite safely in a busy anchorage. We have a sediment filter, 20 micron filter, 5 micron filter, HP membranes then UV treatment before the watermaker water finally hits the tank. We have so much fresh water we can live pretty similar to being at home but we still dont waste it

 

[pcatterall]

All interesting stuff, thanks for the contributions. Am inclining to the new 'dedicated' sea cock and then splitting with a pipe to to the galley sink. I wonder if the galley sink could just use a manual pump on the tap rather than more electrics. That leads me to consider ( something I keep thinking about) fitting a manually pumped pipe to our 100 gallon 'fresh' water tank. If our power or pump went it would be hard to access that water. Possibly I could use a diverter on the galley tap pipe so as to either draw sea water or draw from the tank.

 

[geem]

All interesting stuff, thanks for the contributions. Am inclining to the new 'dedicated' sea cock and then splitting with a pipe to to the galley sink. I wonder if the galley sink could just use a manual pump on the tap rather than more electrics. That leads me to consider ( something I keep thinking about) fitting a manually pumped pipe to our 100 gallon 'fresh' water tank. If our power or pump went it would be hard to access that water. Possibly I could use a diverter on the galley tap pipe so as to either draw sea water or draw from the tank.

If something goes wrong you risk contamination of your fresh water tank. I wouldnt do it. Also consider that under way you will get air draw under the front of the hull. It would be better to install a dedicated intake for the watermaker further back on the hull. Ours is in the engine room as low on the hull as possible. We get no air problems. On our previous boat the intake was too close to the surface so it pulled air in.

 

[dgadee]

If something goes wrong you risk contamination of your fresh water tank. I wouldnt do it. Also consider that under way you will get air draw under the front of the hull. It would be better to install a dedicated intake for the watermaker further back on the hull. Ours is in the engine room as low on the hull as possible. We get no air problems. On our previous boat the intake was too close to the surface so it pulled air in.

Yes, same here. I put it at the lowest part of the hull beside the engine intake. Can't see any advantage in combining piping. It just makes me think with extra connectors and jubilee clips, something will go wrong. Direct from the watermaker to the hull inlet is simple and effective.

 

[pcatterall]

Not me. We dont want or need a salt water pump in the galley. I wouldnt want to use it in a busy anchorage where people use their sea toilet. By comparison our 200l/hr watermaker can be used quite safely in a busy anchorage. We have a sediment filter, 20 micron filter, 5 micron filter, HP membranes then UV treatment before the watermaker water finally hits the tank. We have so much fresh water we can live pretty similar to being at home but we still dont waste it

I guess most people would not choose to use sea water in 'a busy anchorage'? There are many cautions about using water makers in those same anchorages, perhaps more biocide use is called for in those conditions?