Mystery Leak

[Myronaj]

Hi all, first time poster, long time follower.

I have a mystery leak on my full keel Bayfield 29, first noticed last summer with a regular drip, drip, drip into the bilge, estimated rate of 10L or one bilge pumpout per hour. No sign of surface source anywhere - through hulls, cutlass bearing all good, no rain for months, no trickle of water across the cabin sides or sole, and unfortunately no DIY option on West Coast Vancouver Island for a pull-out. So we settled for monitoring it and maintaining the battery/bilge pump hoping to bring it around to an eastside or mainland yard this summer. Oddly, the leak diminished significantly in winter to one pump-out per day.

Unfortunately the leak rate increased even more this summer to a pump-out every 15 minutes or so and as we didn't get a chance to relocate we arranged for a pull-out at the one remaining west coast boat-yard at Ucluelet. When they said they would get me in this week, I braved the storm and made the trip down the Alberni Inlet. While tied up at their dock waiting for pull-out, I noticed the leak had slowed to maybe two pump-outs per day. The summer water is much colder near the coast than way up the inlet in Port Alberni. Yesterday they sent a diver down with air to try to find the leak - no luck, but not surprising given the way it has slowed down. Due to operational issues and the long weekend, pull-out is now scheduled for Tuesday. If the leak is not obvious, the only idea is to fill the bilge as full as we can and hope it will become obvious.

In the meantime, I am looking to the wisdom of this forum to suggest what kind of issue might be acting this way and how best to locate it. I will follow up with whatever we find when I know more.

Much thanks, Myron on Tove

[Kettlewell]

First check every known through-hull fitting, seacock, where the shaft leaves the hull, etc. I have found it is helpful to shine a flashlight on the area and wait a few minutes to see if there any drips. Sometimes you can wrap the area in a paper towel to see if it gets wet. One of my seacocks (the engine intake) developed a hairline crack last summer that let a fine mist of water out whenever I had it open to run the engine. It sprayed in such a way that it wasn't obvious until I noticed some drips running down the inside of the hull from the area. Another thing you can do is go below when it is really, really quiet. Like at a sheltered dock at night with nobody around, turn everything off on the boat for max quiet, and just sit and listen very carefully for awhile. I once found a leak caused by some missing caulking on a wooden boat this way. Another possible point of entry is where a rudder stock penetrates the hull. Also, don't forget your freshwater tanks and onboard water system. I once thought I had a large leak and it was actually the hose at the bottom of one of my big water tanks.

[Myronaj]

I have checked every throughhull, seacock, the shaft seal, etc. and diligently scoured the floor and sides for any hint of a trickle of water. Can't be rain water as it hasn't rained for months, can't be tank water as I haven't filled the tank for months. It is fairly obviously coming in through the side of the bilge beside or behind the fuel tank where I can't see it but I can clearly hear the drip, drip, drip. The well under the engine - above and behind the fuel tank, is dry, so not a leak in the cooling water intake. My imagination says it is some kind of crack in the hull or keel that has filled the encapsulated keel cavity and is flowing out in a channel it has found into the bilge. But why would it run fast in summer and then slow down in winter or when I took it into cooler waters? Like I said, its a mystery leak.

BTW, while I am seeking your advice, is it common or recommended to install a garboard plug in the bottom of an encapsulated keel to drain whatever might accumulate there when the boat is pulled out? Thanks again for any suggestions or advice. Myron on Tove

[Kettlewell]

It is good you have identified the potential area where the water is coming in. Sometimes boats have old through-hull fittings no longer in use that maybe have not been plugged properly. Do you recall hitting anything hard recently? There could be a small hole in the bottom of your keel. I would examine the leading edge of your keel too, particularly where it joins the hull. Even a very tiny crack below the waterline will admit a lot of water. Possibly this tiny crack gets covered with ordinary slime and stuff slowing it down at times. If a diver finds any potential cracks I have had good success using underwater epoxy. But, it sounds like the type of mystery leak that might not be indentifiable until the boat is hauled out of the water. Yes, if your boat is hauled for the winter many install a bilge plug. My boat does not have one so I add antifreeze (the pink stuff) to my bilge in the winter to prevent any water from freezing.

[deblen]

This vid may help. / Len

https://www.youtube.com/watch?v=IsOORovAsrE