Leak-Quest

[jaysweet]

So I've been pretty busy with life and getting the boat ready to launch, but I did do more leak investigatng over the past couple of weeks. The answer is: 99% of the leak was from the GPS puck on the rear quarter on the starboard side:

This was original to the commissioning of the boat in 2004, and was used by our old Raymarine C80 (RIP). At some point, I unmounted it and replaced an internal coin battery, and I thought I used 4200 or some such to bed it down, but whatever I used has now started to leak profusely (like a gallon per rainstorm).

In finding the leak, I initially taped plastic over the cockpit shower box, the engine panel, and the bilge blower exhaust, and still got about a gallon of water in the bilge the next rain. I then taped over the GPS puck, and have had virtually no water in the blind bilge since then. So I'll need to unmount the thing some time soon and either do a kludgy temporary repair (caulk or 4200), or figure out how the heck I'm going to plug 3 holes and finish off the gelcoat so it doesn't look terrible.

 

[jaysweet]

I am still getting a small leak in the aft cabin (near the puck), the source of which is completely mystifying. I think I'll have to climb back there with a flashlight during a rainstorm to find it.

 

[LLoyd B]

Crazy Dave Condon has suggested to find a leak of this type you could spray the suspected leak areas with bubble solution then pressurize the hull using a shop vac or leaf blower. no guarantee but worth a shot. butyl tape is your friend

 

[jaysweet]

Long-deferred follow-up: The bilge was dry for months (with the GPS puck hole covered over), and then I started to get like 2-3 gallons of water in the bilge for no reason I could figure out. In early August, I actually completely emptied it and went for a sail, and had another gallon in the bilge. This made me strongly suspect a leak from the fresh-water plumbing system. After a couple more times of emptying a gallon or two from the bilge, it occurred to me to turn off the water cut-off between the water pump and the tank. This was a test: is it a plumbing leak, or a deck leak? Well, the bilge was dry when I visited the other day (despite several rain storms), so I think I have my answer: the original leak over the winter was from the GPS puck, but now I have a plumbing leak. Not too surprising with 22 year old PEX piping. After the pump and Hot Water Heater, it only tees off for the galley sink, the head sink, and the stern shower. So I think it shouldn't be all that hard to track down. My hope is that it's only a cracked fitting.

 

[Davidasailor26]

After the pump and Hot Water Heater, it only tees off for the galley sink, the head sink, and the stern shower. So I think it shouldn't be all that hard to track down. My hope is that it's only a cracked fitting

If the leak is after the pump you’ll hear the pump cycling to rebuild pressure every few minutes (or hours, if you have an accumulator). If closing a shutoff at the tank stopped the leak, and the pump doesn’t usually cycle, then my guess is the leak is between the tank and the pump.

 

[jaysweet]

If the leak is after the pump you’ll hear the pump cycling to rebuild pressure every few minutes (or hours, if you have an accumulator). If closing a shutoff at the tank stopped the leak, and the pump doesn’t usually cycle, then my guess is the leak is between the tank and the pump.

Yeah, it's still a little mysterious. The time when I emptied the bilge, went for a sail, and found a gallon in the bilge afterwards: I did have the pump on the whole time, but it's not so loud that I would have heard it cycle from up in the cockpit. I'm not sure how it would have gotten 3 gallons of water in the bilge during a couple of weeks of sitting in the slip with the DC power off, though, except that the water tank is higher than most of the piping connections, so just gravity could make it leak if there's a cracked fitting.

Re. your last sentence: there's maybe a couple of feet of piping between the water tank and the pump, and the shutoff is right at the pump (on the tank side). So if I shut it off there and got no leaks, there's probably no leak between tank and pump. Another factor: the pump and hot water heater are pretty far forward (under the forward leg of the salon settee), and the blind bilge that seems to be receiving the water is just at the base of the companionway steps, further aft. As it happens, this is where I'd expect the majority of the fittings to be: on either side of where the blind bilge is. So that's consistent with a leak where one of the hot/cold tubing pairs T off to go to the galley sink or the stern shower or the head sink. Or possibly where the tubing connects to the sinks themselves. I think I just need to get at all the fittings and wrap them with some dry paper towels and go for a sail with the pump turned on. Not what I'd like to be doing before a big trip in late September, but that's life.

 

[Woodworks1]

You could have more than one issue.
I had a prop shaft seal, window seals and fuel cap seal. They kept me busy this season.

 

[jaysweet]

You could have more than one issue.
I had a prop shaft seal, window seals and fuel cap seal. They kept me busy this season.

Yeah: that's my biggest fear. I'm determined to track this down and satisfy my dry bilge fantasy. But if more than one thing is happening at the same time, it can escalate the difficulty of the diagnosis. Gives me a headache, if I'm being honest. But get on with it, as they say. (or "get'er done", if you're into Blue Collar Comedy...).

 

[jaysweet]

Man: I would say "this is starting to get really intriguing". Except that I'd really prefer that it was straightforward, which it is not.

Today, I went out for a sail. When I got to the boat, there was a little water in the blind bilge. Like maybe a pint. So the fresh water cutoff was still... cut off. I vacuumed the water out and completely dried the blind bilge. No water in the main (deep) bilge. To be fair, I've been calling the blind bilge a "blind bilge" for years because I thought it didn't drain anywhere, but I found out this summer that it actually does drain into the deep bilge. The drain hole is just up high enough (and it's hard to see) that this only happens when you get a gallon or two in the blind bilge. So it's not really blind: it just can't see very well.

Anyway. I also taped dry paper towels around every freshwater pipe fitting I could see, and around the pipes themselves lower down. Here's where (I think) the hot/cold supply tees off to the head sink and to the stern shower:

This is in the head sink cabinet. The supply comes in from the left side. I also noticed a puddle on the floor of the head in 2 places. I dried this up, and taped over the floor drain, which leads either to the deep bilge or the blind bilge (I"m not sure). I wanted to see if all the water in the blind bilge is coming just from this drain.I also taped some dry paper towel on the floor next to the taped over drain.


I then went for a sail with the water pump on and the freshwater cutoff on. When I got back to the dock, the bilge was bone dry, but there was a puddle on the floor of the head. All the paper towels I had wrapped around pipes and pipe fittings were bone dry (as far as I could tell).

So I'm still not sure what's going on, but my working theory is:
1) The water in the bilge is all migrating from the head floor through the drain.
2) The water that's been ending up on the floor is _probably_ coming from a rain leak somewhere above the head. This would be the winch, the window, a rope clutch, or...maybe a stanchion or the hull/deck joint (which I tediously rebedded 5 years ago, so I sure hope not). The fact that the puddle has some brownish color supports this (and makes me worry about wet deck core).
3) Or the water is coming from a freshwater plumbing leak that isn't one of the obvious fittings I wrapped in paper towel. I suppose it could be a split PEX pipe somewhere lower down from the paper towels, although this seems unlikely.

I'm really not sure how to tell between #2 or #3.

 

[jaysweet]

So in the head ceiling, I have a winch, a rope clutch, and another rope clutch. I got the panel down that covers the head ceiling, and it all looks really good. No signs of leaks:

You can clearly see the squares of balsa, and there's no discoloration that I can see. If this were the source of the leak, I'd know it. The portlight in the head is another suspect, but it looks perfect as well:

I'll admit that it's a bit scary seeing the raw, uncoated balsa there, but it all looks perfectly dry and unstained. I'd love to take the port lights off and coat the plywood with some epoxy. This is probably not likely to happen any time soon. This is a standard Lewmar portlignt, BTW, and I only had to take the plastic trim ring off the inside to see this inner core.

So given that the leak is ending up on the floor of the head, I have only 3 remaining possibilities (that I can think of):

1) the hull/deck joint. I can't see any stains running down the side of the hull inside the head sink cabinet, but it's sort of unclear what's hull and what's a separate liner. I took the rubrail off 4 or 5 years ago and resealed the joint as well as I could, but when you put the rubrail on, you're basically driving large screws right into the joint (!) through the 5200. This is a terrible design, although the rubrail looks really functional if you don't think too hard about how it's attached.
2) one of the stanchions
3) the holes where the sea hood attaches around the companionway.

 

[jaysweet]

I'm actually really curious about what the "spare wires" up in the overhead are, visible in picture #4 above. Almost certainly pre-wire for something. The only thing I can think of is a powered winch. Note the bump-out in the ceiling panel (which is near the winch, but doesn't really look quite big enough to accommodate one). OTOH, who needs a powered winch on a 30-footer? And what's the solid black line doing up there, with out a large diameter solid red?

As I explore the dark recesses of the boat, I'm finding more and more of this type of thing.

 

[dlochner]

I'll admit that it's a bit scary seeing the raw, uncoated balsa there, but it all looks perfectly dry and unstained.

The balsa looks like it is sealed with chopped strand mat (CSM) and resin.

 

[jaysweet]

The balsa looks like it is sealed with chopped strand mat (CSM) and resin.

Sorry: do you mean in the overhead, or around the cutout for the portlight frame? The portlight cutout looks like raw bare wood to me (viewed up close). The overhead looks sealed, and (I'm no fiberglass expert) I do perceive quite a few nasty, sharp strands that make CSM seem like a good description.

 

[dlochner]

Sorry: do you mean in the overhead, or around the cutout for the portlight frame? The portlight cutout looks like raw bare wood to me (viewed up close). The overhead looks sealed, and (I'm no fiberglass expert) I do perceive quite a few nasty, sharp strands that make CSM seem like a good description.

Yes I was referring to the overhead. The brown stuff between the headliner and the cabin side does not look like wood to me, could be some filler or it could be wood. I don't see any wood grain, nor do I see the seams between the end cut balsa. If it is wood, then it is likely plywood, but the plies aren't visible.

Take a little sandpaper and sand the filler or drill a small hole to see what it looks like. When you're done investigating, fill the hole with some epoxy.

 

[jaysweet]

The stuff in the overhead is absolutely epoxy on balsa. There's nothing unsealed up there, and I see no signs of moisture.

OTOH, around the cutout for the portlight, I'm looking at raw wood sandwiched between layers of fiberglass. But it's all dry and pristine. It seems clear to me that my leak is somewhere I haven't exposed yet. On the one hand, I very much fear it's the hull/deck joint. I'm not eager to pull the rubrail off again. On the other hand, if it's leaking there, at least we're not talking about something that's getting balsa core wet, since there is no core in the hull (to my knowledge). It's really just an annoyance.