Engine water inlet valve - best procedure ?

[vyv_cox]

Impellers have to be pretty dry to get destroyed, I reckon the exhaust hose might die first.
Many boats take a long time to show the water is turned off, as there's enough water in the exhaust to splutter for quite a while at low rpm.
I leave seacocks on in general, if they are going to fail, I expect they'll shear right off the hull. I do check the hoses more than once a year though....

When I was forced to run my engine with no water, right in the middle of the entrance to Scheveningen harbour, it was the plastic water trap that suffered. I didn't know at the time but found the damage later in the season. Fortunately the trap was not holed.

 

[GrahamM376]

Our raw water inlet stays open 9/12, whenever we're on board. Never know when the engine will be needed in a hurry.

 

[owen-cox]

I also leave my seacock open all the time I am on board and I leave the key in the panel whenever I am at sea in case of emergency.

 

[Lyndsey Doyle]

Good afternoon, my main engine seacock's always open, why not. Big bronze valve, double clipped hose etc.

My niggling worry, (which I wonder if Sarabande has as well.. )is the crappy log paddlewheel skin fitting, made of brittle Chinese plastic, which occupies a vast amount of space around itself, because you can't ram stuff under that berth in case the plastic fitting gets snapped off.
If it snapped, the bilge pumps would not keep up, and I would soon sink.
I would like to find a bronze log fitting if they made them but they don't of course, all plastic junk..LD

 

[pvb]

I would like to find a bronze log fitting if they made them but they don't of course, all plastic junk..LD

Airmar have a number of bronze through-hull log transducers, used by Raymarine, Garmin, etc.

 

[charles_reed]

I find the OP's original thesis unbearably complex and meeting no useful purpose.

When I leave the boat, afloat and unused, I just hang the start-key on the (off) raw-water inlet valve handle.

I've had raw-water hoses fail (never between inlet valve and filter) and can vouch for the speed at which the bilges fill with water (but that ONLY happens under power).
As the OP proposal offers no defence against that, I'll carry on with frequent (service interval) inspection of all hoses from inlet to elbow, and their regular replacement.

 

[AntarcticPilot]

It seems to me that the risk of damaging the engine by running it with the sea-cock is shut far exceeds the risk of flooding if something goes wrong with the sea-cock open. Mine stays open, except when I'm working on the engine cooling system.

Note also that shutting the sea-cock does not eliminate the potential for nasty things happening; the through-hull fitting can corrode just as easily as the valve and other inboard parts.

 

[Lyndsey Doyle]

Airmar have a number of bronze through-hull log transducers, used by Raymarine, Garmin, etc.

Excellent, thanks you're a gent, LD

 

[chrishelen]

Mine is left open, can't see the point of closing it, I have double clipped and armoured water hoses.

 

[seadrift]

The scoop to the raw water seacock leading to my Yanmar 3JH2e faces forward.
I have seen a number of comments (on CruisersForum) about the risk of water entering the engine via the exhaust mixer/elbow when sailing with the engine off and the seacock open.
I do not know how much flow will get passed a stationary impeller?

 

[vyv_cox]

The scoop to the raw water seacock leading to my Yanmar 3JH2e faces forward.
I have seen a number of comments (on CruisersForum) about the risk of water entering the engine via the exhaust mixer/elbow when sailing with the engine off and the seacock open.
I do not know how much flow will get passed a stationary impeller?

Exactly. The answer is 'none'.

 

[nigelmercier]

My niggling worry, ... is the crappy log paddlewheel skin fitting...

Easily solved by glassing a pipe around it, to above the WL.

 

[Blue_mischief]

I just had the engine start key on a short piece of line. The engine sea cock was the lever type and I just hooked the string over the sea cock lever when I closed it. Meant that I couldn't get to the engine key without opening the sea cock---simple and pretty fool proof.

+1

 

[prv]

Easily solved by glassing a pipe around it, to above the WL.

I think I'd rather fit a bronze one than have a huge pipe all the way up to the waterline. On some boats that would be long enough that you couldn't get your arm down it to extract the thing!

Serious steel or aluminium boats have been known to fit sealed coffer-dams around the inside part of the transducer, with a bolted-down lid. I have a similar shaped arrangement around mine, but it's made of ply and the top isn't watertight. The idea is to catch the water that comes in when the transducer is removed (formerly it ran into a wiring duct, which is far from ideal!), and it also provides protection so I don't need to worry about stowing tins in that locker.

The plastic housings are tougher than you might think though. I had to remove one last winter, couldn't free it from the Sikaflex in the hole, so decided to break up the "flimsy" plastic in place and pull it out in bits. It put up a real fight, and took a long time with a lump hammer and chisel. An unexpectedly difficult job, but quite reassuring to know they're so strong.

Pete

 

[RichardS]

Exactly. The answer is 'none'.

+1

And not only that but you would have had ample warning that scooped water is flowing through your seawater filter and past your stationary impeller because the last time you used your engine it would have overheated and blown itself to smithereens!

Richard

 

[pvb]

The scoop to the raw water seacock leading to my Yanmar 3JH2e faces forward.
I have seen a number of comments (on CruisersForum) about the risk of water entering the engine via the exhaust mixer/elbow when sailing with the engine off and the seacock open.
I do not know how much flow will get passed a stationary impeller?

Welcome to the forums. I'm afraid that your intake scoop is incorrectly fitted - the slots should face aft. Regardless, water won't be forced through the raw water pump.

 

[seadrift]

Yes, others have commented on the scoop direction while the boat was on the hard.
The boat has a very reputable designer and builder (W.B. Crealock and Pacific Seacraft)...

 

[pvb]

Yes, others have commented on the scoop direction while the boat was on the hard.
The boat has a very reputable designer and builder (W.B. Crealock and Pacific Seacraft)...

But presumably Mr Crealock didn't fit the intake himself? Next time the boat's out of the water, it might be worth rotating the fitting.

 

[lw395]

But presumably Mr Crealock didn't fit the intake himself? Next time the boat's out of the water, it might be worth rotating the fitting.

Is it one of his double ended boats?

 

[rogerthebodger]

I

Serious steel or aluminium boats have been known to fit sealed coffer-dams around the inside part of the transducer, with a bolted-down lid. I have a similar shaped arrangement around mine, but it's made of ply and the top isn't watertight. The idea is to catch the water that comes in when the transducer is removed (formerly it ran into a wiring duct, which is far from ideal!), and it also provides protection so I don't need to worry about stowing tins in that locker.


Pete

Thats exactly what I have done on my steel boat but on a GRP boat you could class one of those O-ring sealed 110mm dia PVC domestic waste pipe connectors so a PVC pipe can be temporary fitted to reduce flooding then removed after cleaning the transducer.

I am about to fit a PVC O-ring fitting to one of my seacocks to allow me to rod the seacock when it gets blocks (don't ask why).