Water leak - but where?

[chris66]

When I fill up will fresh water it leaks down into the bilges, obviously something I need to stop - especially in a mahogany boat...
I have reached the conclusion that the boat was built around the tanks and inspection is very difficult - I have looked everywhere around the tanks and piping (where possible) but no signs of any leak and yet it loses around 10 litres an hour into the bilges, port side first.
The circuit stays under pressure so the problem is before the pump.
I was wondering if it is possible to get some kind of food dye (?) to add to the tank and see where it comes from, or blow compressed air through the circuit and listen for a hiss ? Even if I saw where the dye etc. was seeping from I feel that I may have to cut panels in the floor of the lockers just to be able to inspect the tanks, piping etc.
Any ideas as I am well and truly stumped.......?

<hr width=100% size=1>Chris

 

[dickh]

Do you have a vent pipe? - usually vented overboard, maybe it's come off/perished and any overflow is going into the bilges?

<hr width=100% size=1>dickh
I'd rather be sailing... /forums/images/icons/smile.gif

 

[chris66]

That was quick !
There are two vent pipes but the problem is that even if I half fill up, the water still finds it way into the bilges.

<hr width=100% size=1>Chris

 

[MADFISH]

How about putting a flexible tank inside the existing one??

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[Aja]

Had a similar problem last season with flexible tanks. I used talc - shake over all the connections, and underneath the tank if accessible.

Pump out all the water and refill.

I found that the tanks, hoses and connections were all ok - it was the Gusher foot pump that had gone. Be careful though - where the water disturbs the talc is not necessarily where it is coming from!

Good luck

Donald

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[Evadne]

Does it fill up the bilges when the boat stays upright, or are you on a mooring where she will occasionally heel over so water can flow out of the vent pie/filler pipe/sink tap?

Also: I had a trickle leak from one of the welded seams on an s/s tank which, like yours was put on a coat hanger for the boat to be assembled around. When I finally got to the tanks I found Acrylic Putty was the only thing that would adhere and stop the leak.

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[chris66]

I had thought of that , but I have four tanks, three inox and one new plastic. One of the inox tanks has been shut off as it was leaking and is not accesible. I am not sure where the leak is and indeed if it coming directly from a tank. The two larger tanks midships are fine, no leaks detectable (as i said one is new), problem must be with the tanks further forward but they are unaccesible (unless I start cutting hol;es in the cabin floors) all I see when I lift the gangway floor boards is the top of one of the large tanks which is larger than the opening and that's all !
I did think about sawing this open from above and inserting a rubber lining/flexible tank although the problem may not even be that tank and indeed as the pipes dissapear under the front tanks I'm not even sure that this is not the tank which has been completely shut off.
Real problem is that boat is from 1976 and I have no plans or idea whats happening where the tanks/pipes are not accesible or visible.
I just know that this is slowly depressing me ..!

<hr width=100% size=1>Chris

 

[chris66]

I had thought of that , but I have four tanks, three inox and one new plastic. One of the inox tanks has been shut off as it was leaking and is not accesible. I am not sure where the leak is and indeed if it coming directly from a tank. The two larger tanks midships are fine, no leaks detectable (as i said one is new), problem must be with the tanks further forward but they are unaccesible (unless I start cutting hol;es in the cabin floors) all I see when I lift the gangway floor boards is the top of one of the large tanks which is larger than the opening and that's all !
I did think about sawing this open from above and inserting a rubber lining/flexible tank although the problem may not even be that tank and indeed as the pipes dissapear under the front tanks I'm not even sure that this is not the tank which has been completely shut off.
Real problem is that boat is from 1976 and I have no plans or idea whats happening where the tanks/pipes are not accesible or visible.
I just know that this is slowly depressing me ..!

<hr width=100% size=1>Chris

 

[alan]

Is it possible to fill the tank using an inspection/cleaning hatch on the tank?? This would illiminate the filler pipe itself. As previously suggested using talc is a good idea, I have used it on a number of occasions to trace leaks ......... however where the talc gets wet is not necessarily where the water is coming from !

I would try and "break" the sytem down into parts, and fill them one at a time and try and identify which part is leaking ........... e.g. block off the input to the pump, drain the high pressure side, refill the tank and ensure that it really is on the low pressure part of the system. e.t.c. e.t.c.

It won't be easy ......... good luck.

Alan.
Netuno, Italy.

<hr width=100% size=1>Alan Cloke

 

[Heckler]

do it methodically and logically, had a maddening leak in my beneteau 351 water system, put half a bootle of orange food dye in the tank, about 25 ccs, obtainable from any supermarket in the cake making section.
then i could see backwards where it was coming from, found out that it was one of the stiff plastic hot water pipes in the heads, had a pin hole in it.
stu

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