Water Leak

[Budgie]

I have a puzzling water leak on my 1997 Moody 40, and I would be grateful for any advice.

Hearing the auto bilge pump running on occasion last summer, during this winter I had the keel bolts checked - one or two were very slightly loose. I thoroughly dried the bilge and relaunched.

After a stirring sail I found a significant quantity of water in the bilge. I then lifted all the saloon furniture and flooring, and dried the bilge. I bunged up all the holes joining the bilge sections with plasticine.

Yesterday I went out on blustery day, and while motoring the bilge remained dry. However as soon as we raised the sails and got some heel on the boat a significant quantity of salt water appeared in the forward section of the bilge.

No source of the water was apparent - no water was leaking from the depth or log transducers. There are no above waterline skin fittings in the immediate area. There are fittings for the fwd heads, but these are under water at all times. The covers were off the water tanks which are situated under the saloon seats, but no water was seen in the immediate area.

The boat is centre cockpit, with heads forward and aft.

Any ideas would be welcome.

 

[claymore]

Have a look in the anchor locker and see if it can find its way out from there. Was the hull deck joint under water and could that be a source. Are you sure that all areas of the bilge are dry and this isn't some water finding its way from an existing puddle?
Sod isn't it!!
I once had someone sit below with the floorboards up whilst we sailed to try and find a similar problem - it was coming from a water tank but because it was getting into the bilge it mixed with salt that was already there and so we thought it was sea water.

regards
JohnS

 

[rogerroger]

Are you absolutely certain it's salt water ? I had what I thought was a leak which turned out to be something else but baffled me for months... (no need to bore you with it if it's definitely salt water).

Roger Holden
www.first-magnitude.co.uk

 

[iangrant]

I chased a leak like that hoping it would gret better and sure enough it was the keel bolts. I think you know the answer - Keel bolts - firstly you found loose bolts, therefor the seal is cracked (even if you have tightened up the nuts) secondly it only lets in water when heeled - (pressure on the keel opening up the cracks) - I'd haul her out drop the keel - clean off, re-seal and tighten, after I'd spoken to the builder/surveyor about the latent defect!

Good luck -

Ian

 

[Trevor_swfyc]

I note you said the covers were off the water tank and you had a stirling sail, I would be surprised if the water stayed in the tank. I note you said it was salt water but any water in the bilge will taste salty so how do you know its sea water?
The best way to eliminate the tank/chain locker or similar is to put some food colour in the water tank water, another colour in the chain locker with some water. If after a good sail and the water remains clear in the bilge you have eliminated these two possibilities.
I had a similar problem in a short chop comming down stream on the Thames with a strong head wind. It turned out to be fresh water from the water tank the movement of the water in the tank was causing enough pressure in the connecting pipe work to force a leak at the water pump connection.
Please come back with your findings.
Good luck
Trevor

 

[billmacfarlane]

You might have answered you own question when you mention that 2 of the keel bolts were slightly loose. What has caused the keel bolts to loosen slightly ? There's a possibility that when the hull is under the stress due to sailing , the hull is flexing slightly , causing slight water seepage at the keel bolts. The only way you're going to prove it one way or the other is to dry the area thoroughly , pull up the floorboards , and have someone ( with a strong stomach ) feel round the bolts when the boat is under sail for any sign of water ingress. As a matter of interest does the problem happen on both tacks ? If so it almost certainly eliminates any skin fitting. As someone has already asked are you 100% sure that the water is seawater ?

 

[Guest]

i have a vague memory (so it might well be wrong) of a yard manager telling me that he had just had to do remedial work on the anchor lockers of a new moody 40 he had sold

as i said, my memory is vague, and you cannot always believe what you are told anyway, but i would carefully check the anchor locker, followed by the window seals, seacocks etc.

 

[Budgie]

Thank you all for your replies - they are all very useful.

This afternoon I plugged the anchor locker drains and half filled the locker with fresh water. Inside the V-berth I noticed a slight but persistent hissing sound - like a tap very slightly on. I removed the anchor chain, and then the plugs. The water rapidly drained away via the normal drains, but as it did so I saw short lived jets of water appear from the aft bulkhead. Examination appears to reveal pinhead holes.

I am surmising that water found its way behind the bulkhead and collected under the V-berth (an inaccessable area). When the boat was heeled this water found its way round the end of the ribs and collected in the main bilge.

I'll give Princess/Moody a ring in the morning and check this scenario with them.

I have also heard of modifications made to Moody 40 anchor lockers, so I'll enquire further.

Once again, many thanks for all the prompt and helpful advice.