EMERGENCY! Help, found a leak!

[schrater]

In the middle of a long 11hr run to the San Juan’s. Noticed bilge pump was running more than normal.

Found a leak in the aft cabin bilge floor, right about centerline. There is a fingernail-sized chip of fiberglass missing and water is percolating up through it. This is aft of the stuffing box, I believe directly above where the prop shaft passes down the length of the keel (this is a single engine boat).

I guess water would naturally be in that space anyway, and so this is just an internal fiberglass “floor” issue? Or is this a sign that I have a much bigger problem of a leak in my hull?

 

[Simi 60]

Time for a swim.
Looks like impact from outside

 

[Blissboat]

Agree with Simi - someone is going to have to go over the side and have a look at this spot from below. It's unclear from your description whether the bit of fiberglass is missing from the inside of your actual hull skin, or some other surface. When in doubt, though, assume the worst until something else has been proven. The main job of your boat is to keep the water out.

 

[High Wire]

Could be a strike or a delamination. You can probably plug it temporarily with epoxy putty like JB Weld until you can get a haul out.

 

[hollywood8118]

Could be a strike or a delamination. You can probably plug it temporarily with epoxy putty like JB Weld until you can get a haul out.

I tend to agree with the patch suggestion above, scratch it with some 80g. sandpaper, rinse with fresh and apply some fairly thick jb weld.
How often when the boat is at anchor does the pump cycle? how far below water level is this leak?.

Can you get a shot further back .. don't quite understand the spot.
HOLLYWOOD

 

[Simi 60]

I tend to agree with the patch suggestion above, scratch it with some 80g. sandpaper,

Don't dick around polishing it
Get in there with some road base, 36 grit, rip it up properly in seconds.

 

[hollywood8118]

Don't dick around polishing it
Get in there with some road base, 36 grit, rip it up properly in seconds.

I once watched a guy jab a key into a dark spot on the bottom paint on a commercial boat sitting on the hard in a boat yard. As the new to him geyser of diesel was raining down I whittled a soft plug out of a wood wedge and gently jabbed it into the hole to stop the flow.
I have since become a touch more careful around fluid leaks on boats.
HOLLYWOOD

 

[gsholz]

Many of these boats have a hollow keel with just a bit of fiberglass on top. Water found its way into the keel and is now percolating up. Next time you haul out observe areas remaining wet. That is likely where the water enters the keel. In the meantime I'd patch it as suggested above.

 

[Simi 60]

And here was me thinking there'd be a 1/4 inch of flowcoat/gelcoat before actually getting to the glass.

 

[schrater]

To be clear, this is well below the waterline, and water is coming in from below, so I’m not going to be able dry and patch it. I’ll need to track down something that can cure underwater.

But I do not believe this is a spot directly exposed to the exterior. It’s sitting almost directly along the centerline, and I have a full length keel, so I would estimate there is close to 2ft of keel beneath it (see crude diagram and photos).

I guess the point is that since the shaft travels through the keel for about 8ft, and the passes through the stuffing box at the bulkhead of the engine compartment, it follows that shaft channel would have water it in (presuming there’s no comparable shaft seal where the shaft exits the keel.

 

[mvweebles]

If you're looking for something that will cure underwater, try splash zone

https://www.amazon.com/Pettit-Paint...words=splash+zone+epoxy&qid=1629063271&sr=8-3

I agree with Simi. Looks like an impact strike. And I understand your reasoning why it's not. Please followup as I'm curious what this is.

Peter.

 

[RT Firefly]

Greetings,
Mr. s. I tend to agree with Mr. g (post #8). Being constantly wet, there's not too much that will successfully patch it. How much more is the bilge pump actually running? It cycles after how many minutes?

 

[RedRascal]

If you are real close to Shilshole pull in and Uber to Fisheries(open until 4:00). They have quart kits of Splash Zone in stock.
https://www.fisheriessupply.com/pettit-paint-a-788-splash-zone-compound

 

[schrater]

Bilge pump is only cycling every 45min or so, so not too bad. I’ll be in Friday Harbor tomorrow, can probably get a temp patch there (for the inside layer anyway).

 

[NWSeadog]

Based on the description as to the location of the leak I would guess that it is coming from the shaft log (stern tube). Not sure how you would determine that for sure and if that is the problem you would need to pull the boat to replace it. There are lots of underwater epoxy puddys on the market that should temporary block the flow. Even JB Weld makes something called Waterweld that should work. You might have to come up with something to hold it in place until it sets up.

 

[mvweebles]

Question. Have you picked up a crab trap or anything that really got wound around shaft?

 

[rgano]

How does one get an impact hit to the underside of the bilge which is directly over the box of the keel?

 

[backinblue]

Just get a putty knife and some Flex-Seal and you'll be all set, just like the commercials show. Sorry couldn't resist....

 

[Blissboat]

How does one get an impact hit to the underside of the bilge which is directly over the box of the keel?

Good question. This leak's source is TBD, and the answer will be interesting. It's not unusual for a leak to appear some distance from its source.

 

[Lou_tribal]

My 2 cents:
Before trying to do a crappy repair that could make more damage than solve the issue I would go to a nearby port where I can have my boat out of water so to check what is exactly the issue. Water can go a long run in between laminated layers before finding a hole to get out. I would personnally prefer to pay a couple of hundreds to be hauled out and to do a serious look at the hull instead of trying to repair thing quick and dirty and find myself in trouble in ye middle of nowhere later on.

L

 

[STB]

If looking for something that can cure under water, try Splash Zone (Marine stores) or WaterWeld (Home Depot or Lowe's or similar) or Oatley's Fix-it-stick in the plumbing section (Home Depot, Lowe's, etc)

 

[Comodave]

I would put some epoxy that will cure on wet glass. Spread it over the area and when it stops leaking and drys out on the inside lay in a few layers of glass over the whole area. That may fix it permanently.

 

[sean9c]

My guess is that the stainless stern tube has a rust hole in it. Water leaks into the bog that they filled the keel with, percolates around until it finds a way out. I've seen it in 2 TT's here in town and have heard of several others. The repair, replacing the stern tube, is not pretty.

 

[FlyWright]

My guess is that the stainless stern tube has a rust hole in it. Water leaks into the bog that they filled the keel with, percolates around until it finds a way out. I've seen it in 2 TT's here in town and have heard of several others. The repair, replacing the stern tube, is not pretty.

That's what I was thinking...a leaking stern tube. A CHB at my dock has a similar problem on a cored hull/keel. Not a simple epoxy or JBWeld fix.

I'd haul the boat and have a look.

 

[Lepke]

Stay Afloat will stop and hold the leak from either side. I keep it on board.
Home

 

[Frosty]

seanc's thoughts echo mine. Don't know exactly how your boat is constructed, but if I had to guess, some sort of stern tube leak getting in and then "surfacing" where your trickle is.

 

[Simi 60]

Stay Afloat will stop and hold the leak from either side. I keep it on board.
Home

Pretty sure that's toilet ring seal was if chasing the cheap alternative.

 

[Simi 60]

There are epoxies that cure underwater supposedly.
Knead it, aquabond to name two.

 

[STB]

Pretty sure that's toilet ring seal was if chasing the cheap alternative.

Having used both, it is much denser.

I've changed "seacock" valves on thru hulls with integral external strainer scoops, and done similar work, by using toilet ring wax to seal the thru hull. I formed it into a hamburger shaped patty, placed it onto a home depot plastic bag, and squished it onto the strainer. Held for a long time, through a trip to West Marine, etc.

So, I am not at all down on the toilet ring wax approach. But, in warmer water, I would likely have wanted the denser stuff, if given the choice.

 

[schrater]

My guess is that the stainless stern tube has a rust hole in it. Water leaks into the bog that they filled the keel with, percolates around until it finds a way out. I've seen it in 2 TT's here in town and have heard of several others. The repair, replacing the stern tube, is not pretty.

Thanks, I think yore exactly right. This fits all the evidence points.

Temp patch for now to stop the intrusion, then bigger resolution once I can haul out.