Bilge water mystery

K2MSmith

Member III
Most boats I’ve sailed always seemed to have some water in the bilge but I understand that the bilges should really be dry ( at least of saltwater ) so I was determined to find out where water is getting in .
From what I can tell , I’m getting maybe a pint every week. It’s not enough to trigger the float switch and I just pump it out but it would be nice to figure out where the water is coming from .
The big concern might be a small leak around the keel bolts . So I bought some plasticine modeling clay which doesn’t dry ( unless you stick it in a kiln I suppose) and I put a “dam” around each passage way leading into the bilge ( see photos ) . The bilge remains dry after a few hours , whereas before , I would start to see moisture gathering by that time . This is good news ! - doesn’t appear to leak around the keel bolts but where is the water coming from ? I checked all through-hull fittings that I can find and my speed transducer ( took out and replaced with silicone paste on o-rings ) . I can’t feel any water/moisture around those fittings .

Can anyone suggest other places to check ? I’m thinking it’s salt water but not 100% sure . The bolts have a reddish / brownish crud on them which can be brushed off with a bit of effort . If it was a leaky waste tank I would think you would know it (?) . I also took the bilge pump out and verified that it’s not water coming back in through the output hose ( which had a check valve in it but I removed it as per the instructions that came with the new rule pump..- but the line is dry so water doesn’t appear to be coming from the outlet house .
Tomorrow I’ll check it again , maybe some water will be filling in behind one of the clay barriers by that time so I can at least get an idea of which port it’s coming in from .

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Frank Langer

1984 Ericson 30+, Nanaimo, BC
Hi,
Although not always pleasant, a taste test will usually reveal if its salt water or fresh water. If fresh, could it be one of your water tanks, especially at the fittings? In a hard rain, I sometimes have a small bit of water come in one of the cockpit lockers, making its way into the bilge.
Water can often show up far from it's source. On my boat an anchor locker leak came into the v berth and dropped down the bulkhead and showed up as a small puddle in the head. A leak at the traveler end came down the headliner, along the molding below the port and driped onto the galley stove. Careful observation will usually reveal the source.
Frank
 

K2MSmith

Member III
Hi,
Although not always pleasant, a taste test will usually reveal if its salt water or fresh water. If fresh, could it be one of your water tanks, especially at the fittings? In a hard rain, I sometimes have a small bit of water come in one of the cockpit lockers, making its way into the bilge.
Water can often show up far from it's source. On my boat an anchor locker leak came into the v berth and dropped down the bulkhead and showed up as a small puddle in the head. A leak at the traveler end came down the headliner, along the molding below the port and driped onto the galley stove. Careful observation will usually reveal the source.
Frank
I don’t think it is rain related . We have not had any recent rain and the moisture will show up consistently enough to put about 1/4” water in bilge after a few days . It’s not a lot because my bilge is fairly small / narrow . The water tank is a good idea . I’ll see if I can get access to it where the hose outlets come out ( unless the tank itself has a leak ) . The water seems to be coming in around the bilge partition areas ( where two bilges connect via a port, but not from within bilge itself because when I stuff modeling clay around those areas , bilge remains dry .
 

1911tex

Sustaining Member
Perhaps your prop shaft packing nut needs adjusting. I had a similar bilge buildup and could not see any packing nut drips. I put a paper towel under the packing nut and noticed it was wet several days later after not starting the engine. Seems there was a drip every 10 minutes or so...never when I was inspecting or I just did not notice. Over several days, that could amount to your 1/4" bilge water.

The more obvious cause could be mast condensation running down into the bilge?

You sure keep your bilge clean!!
 

kiwisailor

Member III
Blogs Author
I had a similar leak that was filling the bilge and it turned out the hose from one of the cockpit scupper drains had a crack underneath it where it enters the rear thruhull. You couldn't see the crack until I lifted the scupper drain hoses up and water poured out the crack at the thru hull.
 

trickdhat

Member III
Blogs Author
I had a similar leak that was filling the bilge and it turned out the hose from one of the cockpit scupper drains had a crack underneath it where it enters the rear thruhull. You couldn't see the crack until I lifted the scupper drain hoses up and water poured out the crack at the thru hull.
This is a great reminder to check my drain hoses regardless of bilge water. I bet they've never been changed. Finding a crack in the system above water seems like a friendly reminder from the sailing gods in comparison to the alternative. Thanks!
 

K2MSmith

Member III
Perhaps your prop shaft packing nut needs adjusting. I had a similar bilge buildup and could not see any packing nut drips. I put a paper towel under the packing nut and noticed it was wet several days later after not starting the engine. Seems there was a drip every 10 minutes or so...never when I was inspecting or I just did not notice. Over several days, that could amount to your 1/4" bilge water.

The more obvious cause could be mast condensation running down into the bilge?

You sure keep your bilge clean!!
I’ll check the prop shaft packing nut . I know the cutlass bearing was changed a few months before I bought the boat. I don’t know if these items are independent.
I cleaned up the bilge to make it easier to spot the leak, but it was already kept pretty clean by the previous owner which is a good sign ..I would like to clean the bolts / nuts so I’m hoping that some simple green and a wire brush will do ..
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
I’ll check the prop shaft packing nut . I know the cutlass bearing was changed a few months before I bought the boat. I don’t know if these items are independent.
As far as water getting past the shaft packing, no direct relationship. However, if the shaft is not centered in the shaft alley, it will distort the heavy hose that connects to the stuffing box.
( Having the shaft out of alignment can cause vibrations that will cause a drip in our PSS shaft seal, I know from experience.)

Your traditional stuffing box may simply have the fiber rings inside misaligned when they were inserted, or be a tad too loose. While there is one way to insert them 'right', there are several common ways to do it wrong and have a near-unstoppable drip as a result.

Best to view the whole shaft alignment and sealing as a "system". .... and take a really good/focused look at the engine alignment. On any boat with older mounts, the rubber in them slowly compresses and allows the engine to drop. This happened to us in the past -- I found that the shaft was lightly rubbing on the bottom of the shaft alley. New mounts and a good alignment cured that.

And, regarding the advice about drain hoses, they DO develop cracking and holes as the material gets brittle over the decades. Any hose older than 15 or 20 years - and all OEM hose from the 80's - needs to be replaced. Yesterday!
 
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K2MSmith

Member III
I’ll check the cockpit hoses as well. Would the cockpit drain hoses leak water if the boat cockpit was dry ? Also I’m going back to the boat today so I’m hoping that the bilge is still dry with my modeling clay barriers I put in yesterday. If I am able to find a buildup of water behind one of them maybe that wil provide a clue as to where it’s coming from .
 

Christian Williams

E381 - Los Angeles
Moderator
Blogs Author
My boat has no known leaks. Sometimes the bilge is bone dry. Sometimes it has a pint of water in it, or more, salty or brackish.

It seldom rains here, often not at all for six months. I conclude dew is the culprit, because at dawn the decks are sometimes quite wet and the scuppers often have a lot of water (they don't drain with dockside trim).
 

K2MSmith

Member III
My boat has no known leaks. Sometimes the bilge is bone dry. Sometimes it has a pint of water in it, or more, salty or brackish.

It seldom rains here, often not at all for six months. I conclude dew is the culprit, because at dawn the decks are sometimes quite wet and the scuppers often have a lot of water (they don't drain with dockside trim).
I thought about dew because it hasn't been raining here last week and I still get the water, but it is fairly consistent which makes me think there is a trickle of a leak somewhere. I have not checked the hose connections to the water tank or the waste tank yet or the prop shaft packing nut, so that is on my to-do list for today. (along with picking up wire brushes and cleaner from the hw store if it is open )
 

K2MSmith

Member III
Getting warmer . There is a little 1/2” deep puddle near the drive shaft . But I’m not convinced it’s from the packing because I don’t feel water around it . Don’t see any obvious drips but that water definitely 35A90363-36C1-4615-AA5D-DB8DCCC1CB48.jpegdoes go through a port to the bilge .
 

kiwisailor

Member III
Blogs Author
Getting warmer . There is a little 1/2” deep puddle near the drive shaft . But I’m not convinced it’s from the packing because I don’t feel water around it . Don’t see any obvious drips but that water definitely View attachment 36330does go through a port to the bilge .
Check the rear lazarette behind the rudder post. My leak from the scupper drain hoses pooled in the hull behind the rudder, then would flow forward to behind the engine like your picture.
 

K2MSmith

Member III
Check the rear lazarette behind the rudder post. My leak from the scupper drain hoses pooled in the hull behind the rudder, then would flow forward to behind the engine like your picture.
Unfortunately I don’t have a rear lazarette. Got this photo by crawling below deck in the “coffin” ( best to bring a phone and bungee the lazarette door open ) . My 2 cockpit drains are connected to individual hoses that run to thru-hull on the centerline. I didn’t see any signs of leakage with those hoses . Hasn’t really rained / and I have not washed the boat . Found a very small amount of wetness around the house water pump hoses . I tightened those connections but I don’t think it’s enough to cause that much water to pool. Is it possible the bilge water runs back to this pool or is the bilge supposed to be lowest point on boat ? I’d like to maybe get a salinity tester to be sure it’s fresh water . The keel nuts getting some rust would still indicated salt but I did have salt water in there for a period due to slight leak in speed transducer.
 

Kenneth K

Sustaining Member
Blogs Author
More on the coaming box leak. Here's what mine looked like after several days of rain:

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Though the coaming box has two drain holes at the bottom, the large gap between the coaming sidewall and the plastic coaming box meant that the gap filled with water and leaked before enough water ever collected to exit through the drain holes. The trapped water then migrated between the layers of glass cloth that hold the coaming box in place.

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A PO had tried to fill this gap with silicone, which obviously wasn't working. I scraped out as much of the old silicone as I could, thoroughly cleaned the surfaces, thoroughly abraded both surfaces with a knife, then filled the gap with unthickened epoxy. It took a lot of epoxy so I did it in two pours so it wouldn't build up too much heat, and to get the level right. With the dried epoxy sitting just below the level of the aft drain hole, water now properly drains from the aft hole. The forward hole sits up just slightly higher (or the boat sits slightly aft-low), so the front drain doesn't do anything unless the box really gets swamped.

I also lined the interior of the box (as has been recommended by others) with vinyl placemats to protect it from further UV damage. I have the teak trim ring in the garage for re-finishing this winter.
 
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K2MSmith

Member III
Thanks for you detailed post Ken. I don't have combing boxes but I will certainly be looking for other leaks from the lazarette/cockpit area. I splurged 30.00 for a salinity tester on Amazon. These low-cost units look like they are primarily designed for aquarium use but I am thinking they should at least be able to tell the difference between fresh water and salt water. A fresh water pool in the boat would still likely have saline in it, but I am thinking it would be a lot lower than seawater. If the pool is freshwater, then at least I've narrowed it down to rain/dew/moisture from outside the boat or fresh waters lines. I've checked all the thru-hull valves I can get my hands around. There was some moisture downhill of the speed transducer in the forward bilge, but I am not sure if this is remaining water from when I cleaned out the impeller which requires you to remove the transducer and a gusher of seawater goes into your bilge. I have removed this transducer and used silicone grease to on the o-rings. The tightening ring as a stop on it when it is fully tighted which I don't remember noticing a few months ago when I pulled it last, so maybe might be yet another source of trickle...
 

nquigley

Member III
hmmm - might even work for us lake-dwellers if it's sensitive enough.
I expect that our lake water has more salts of various types that rainwater would ever have.
 
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