Is it fresh or salt water??

[mph]

Does anyone know how to check bilge water to see if it’s sea water or freshwater? The obvious has been tried e.g taste it…and it doesn’t taste of anything much..

A chum has found more bilge water than expected in the bottom of his boat, he’ll be leaving the boat un-attended for a month or so soon and wants to know a sure way to trace the likely source.

The boat is a Beneteau 411. The stern gland is a Volvo dripless seal and OK when last checked. The freshwater system could be the source – there is just one pressure pump midships and two long pipe runs from the bow & stern tanks. Any leak in the fresh water system must be on the ‘tank’ side of the pump as it doesn’t keep cycling on and off.

So, does anyone know a way to test if the low pressure system is leaking? Pressure maybe?

 

[kesh]

you could get a salinity tester from those people that keep fish, koi and the like

 

[sailorman]

Does anyone know how to check bilge water to see if it’s sea water or freshwater? The obvious has been tried e.g taste it…and it doesn’t taste of anything much..

A chum has found more bilge water than expected in the bottom of his boat, he’ll be leaving the boat un-attended for a month or so soon and wants to know a sure way to trace the likely source.

The boat is a Beneteau 411. The stern gland is a Volvo dripless seal and OK when last checked. The freshwater system could be the source – there is just one pressure pump midships and two long pipe runs from the bow & stern tanks. Any leak in the fresh water system must be on the ‘tank’ side of the pump as it doesn’t keep cycling on and off.

So, does anyone know a way to test if the low pressure system is leaking? Pressure maybe?

if the pressurised system has a leak & all taps turned off the pump will engage every so often.
no pump going off no leak

 

[NormanS]

if the pressurised system has a leak & all taps turned off the pump will engage every so often.
no pump going off no leak

Not if the leak is before the pump.

 

[sailorman]

Not if the leak is before the pump.

wot have the Romans ever done for us

 

[planteater]

The obvious has been tried e.g taste it…and it doesn’t taste of anything much..

Probably freshwater then.

You could try putting different coloured food dyes into the water tank, heads etc. If the bilge water runs clear and tastes fresh then it's probably rainwater.

 

[trapezeartist]

Checking for leaks on your freshwater system is simple enough. Run your fingers over every pipe, union and whatever that you can find. If your finger gets wet, you're getting close. If all that fails, the often quoted (never had to try it) talcum powder test seems quite a good way of homing in on the source of the problem.

 

[Ludd]

Does anyone know how to check bilge water to see if it’s sea water or freshwater? The obvious has been tried e.g taste it…and it doesn’t taste of anything much..

A chum has found more bilge water than expected in the bottom of his boat, he’ll be leaving the boat un-attended for a month or so soon and wants to know a sure way to trace the likely source.

The boat is a Beneteau 411. The stern gland is a Volvo dripless seal and OK when last checked. The freshwater system could be the source – there is just one pressure pump midships and two long pipe runs from the bow & stern tanks. Any leak in the fresh water system must be on the ‘tank’ side of the pump as it doesn’t keep cycling on and off.

So, does anyone know a way to test if the low pressure system is leaking? Pressure maybe?

First empty the tank/tanks .Switch off pump. Switch off calorifier if fitted. Dry bilges. Any water will then either be due to condensation(fresh --or brackish if bilges are dirty), salty if he's got a leak.

 

[Seven Spades]

it may be rain water

 

[tim_ber]

Silver Nitrate

I think (going by dusty memory here) that Silver Nitrate reacts with salt water to give a visible reaction (cloudy precipitation?). Ask VicS?

Expensive stuff maybe owing to silver content- don't know if local pharmacies stock it - try a nearby university or secondary school?

 

[Cap'n Creosote]

A cheap Beer hydrometer! from Boots.

When I had a similar problem I dipped a jar over the side and took a sample of the brackish estuary water. And floated the hydrometer in it.

Then I took a sample of fresh water from the tank and took another reading.

Then I filled the jar with bilge water and compared the readings.

Result, it was fresh water from the tank.

 

[sailorman]

A cheap Beer hydrometer! from Boots.

When I had a similar problem I dipped a jar over the side and took a sample of the brackish estuary water. And floated the hydrometer in it.

Then I took a sample of fresh water from the tank and took another reading.

Then I filled the jar with bilge water and compared the readings.

Result, it was fresh water from the tank.

your taste buds must be shot

 

[Cap'n Creosote]

You've obviously not tasted my bilge water!

 

[Cerddinen]

I posted a similar question about 2 months ago. The water in the bilge area under the stern gland clearly fresh. After much searching and dismantling I finally traced it to the point where the gps ariel passes though the transom into the boat. The fitting had come loose leaving a small gap. The problem was that it sat exactly in the centre of the flow of rainwater off the decks. My process was to place paper kitchen roll in strategic places leading to the location of the water. The wet paper indicated where the water had to be coming from. This process steadily eliminated a series of possibilities. Now I am waiting for the weather to improve so that I can fix the problem itself.

 

[Leighb]

Does anyone know how to check bilge water to see if it’s sea water or freshwater? The obvious has been tried e.g taste it…and it doesn’t taste of anything much..

You should be able to taste salt at very low concentrations, so if you can't taste salt it's fresh

 

[BobPrell]

Put a couple of spoonfuls into a metal dish.

Heat until the water is boiled off.

Examine residue.

 

[AntarcticPilot]

I think (going by dusty memory here) that Silver Nitrate reacts with salt water to give a visible reaction (cloudy precipitation?). Ask VicS?

Expensive stuff maybe owing to silver content- don't know if local pharmacies stock it - try a nearby university or secondary school?

A curdled precipitate turning black on exposure to light with silver nitrate is the recognized qualitative analysis test for the presence of the Chloride ion.

 

[Boo2]

Does anyone know how to check bilge water to see if it’s sea water or freshwater? The obvious has been tried e.g taste it…and it doesn’t taste of anything much..

I agree with the other posters here who say if you can't taste the salt then it must be fresh but if anyone wants to try something more technical how about an Aquarium Hydrometer ? I couldn't find the same one as I used to use back in my fishkeeping days but the one here looks OK.

Boo2