Hull Leak

[mainesailorman]

I sail a 2008 42i in Maine where lobster trap are part of your life. At times the lobster trap get cut off and can create 100 plus feet of line. I hit one of those tangles and wrapped it around the prop, shaft and supports. Hired a diver to cut the mess off. At the same time, I had water in the bilge area and battery area on the starboard side. Now 2 weeks later no water enters the battery area unless I go sailing. There is no water when I motor or while I am on the mooring. Hired a diver to check for any visible cracks, none. I get about 1 qt. per hour of sailing. No water anywhere except the battery compartment. I wish it went into bilge, no such luck.

Cannot determine why the water is collecting only in the battery compartment and how the water gets into the hull but does make it to the bilge. Liner prevents anyone from seeing where the leak is and how much water is between the hull and the liner.

Any ideas?

[zaphod]

Are you sure it is salt water, and not fresh water from your water tank?

[ds42]

Mainsailorman,
Your leak is probably at the prop strut to hull pocket.  I have a 2008 42DS and picked up a line in the prop.  It torqued the shaft hard enough to break an engine mount and caused a leak in the prop strut to hull bond.  My leak was similar to yours.  Very small amount, just enough to be bothersome.  Turned out water was working its way up the strut and leaking through the copper bonding braid at the top of the strut inside the rear cabin under the bed.

i ended up pulling the boat and used a multi tool to work the edge of the strut all around.  Cleaned it well enough to force a bead of epoxy around the strut. 

Took care of my leak.  Dry as a bone in the bilge now.

Hope yours is as easy!

[Charlie-Bravo]

Lobster pots aplenty here in Wales, ..... some say they are traps laid to catch yachts as they can often be seen just outside a marina !
Ive been tempted to get the boathook out and see if there is anything for lunch inside, if you do and there is, tip of the day is pop it into a bucket of fresh water, ..... it will go to sleep and die, much easier than clamping a lid on the pot and trying to ignore the squealing, ....

As with all problems, one event can often steer the mind to probable cause, ..... and is usual to be completely unrelated to the suspected cause. Quite how it gets into a battery compartment I have no idea as they are usually sealed boxes to prevent acid spillage attacking things, are yours of a sealed nature? or just plywood compartments.
As you don't ingress water whilst motoring I think cultlas / p bracket damage is unlikely as they will be under stress when motoring more than under sail,  so it is the boats list whilst sailing that is producing results ..... clue no.1
Following Zaphods thoughts ......
Fresh water:
On our last boat, we had a similar ingress of water just while sailing well heeled, it tuned out to be a poor fresh water tank cap, leaking on starboard tack, ..... took me ages to figure it out as it always stubbornly refused to leak when being investigated back at the marina berth, and on our present boat we have had a tank cap split and leak, it looked fine, then I filled the tank ..... and the bilges, they are quite dust free now.  the tanks fitted to Jenny's seem to have poor lids as others in our marina have also split, no idea where your tanks are located, or the battery boxes, but it could be the source of the water ...... the other main culprit could well be the hot water tank pressure relief valve and or pipe work, not sailing related but it could be leaking into a hull bilge  compartment, not all areas are designed to flow through to the main bilge on our 35, and the water comes out of hiding when you sail.

Salt sea water:
Ingress only whilst sailing would possibly indicate a problem with a sink drain through hull, as these are often just above sea level, but below water when sailing on one tack or the other, not many places for the sea to get in only whilst sailing ....... unless it's very bumpy.

Hope the above inspires further investigation, looking forward to hearing what it was. when you find out.

CB

[Charlie-Bravo]

Ds42 has typed whilst I was rambling on, and I always admire 'experience' first hand, so probably best to test out his solution first
Good luck
CB

[jeroen]

If salt water, then it could enter through cracks around the P-bracket when the engine is causing vibrations while motoring, though invisible due to the liner. With delay, the water finds it way to the bildge and maybe causing you not to relate it with the engine vibration. If so, then read further here: jeanneau.proboards.com/thread/4797/leak-bracket-joint-after-line

Other possibility, if salt water, a drip/leak at the connection between the muffler and engine exhaust.