Leak in Bilge

Hello all,
New to Trawlers but not boats. I was in the bilge cleaning and hanging cables, etc. last night and noticed there was a very small amount of water "seeping" through the hull. I had dried everything to make it possible to access the parts I wanted to work on. Upon further inspection I found that the water was coming through what appears to be FG over the keel section.

In doing some research I found that some of these TT had stern tubes that would leak. Is there a way to determine if I have a leak in the stern tube that is filling up the keel and leaching into the bilge or if the "normal" water from my packing has leached downward and filled up my keel.

It seems to me that any boat that has had water sitting in the bilge for 44 years would have water going into the keel. My real concern is that I was installing a very small bilge pump to keep this water level down below my (2) 1100GPH main pumps and when I put the screw in water was actually coming up. No, I did not pierce the hull as this is very near center of the boat and on the "flat" portion over top of the keel.

The rudder post/box is not leaking at all. The shaft (drive) stuffing box drips as it should 2-3 per minute. There was indication that water may have been higher in the bilge at one time but the last time I dried the hull when I was scrubbing it out about 1 gallon of water came back in after 12 days or so. I did drive the boat during that 10 day period for about 30 minutes.

I appreciate any thoughts on this. I knew I would have the typical issues with ports and teak decks but this was new, and very concerning to me. I did a tapping test of the hull and it seems very sound. I do believe there is foam, cement, or a void in the keel that is full of water though and I want that fixed.

Thanks,
Jeff

Boat: 35' Eagle Tri-Cabin built by Shin Hsing.
1977 13.6 Beam (a major reason for the purchase- lots of room in a 35')
120 HP Lehman 3.5Kw Yanmar
1.5" Stainless Shaft in typical bronze boxes with bronze cutlass bearings.

Is it possible to haul the boat to inspect the hull?

Jbear

Its very easy to believe a 1977 boat has a leak in the stern tube. Water would permeate the keel fill and show up as you have indicated. My 1979 trawler did exactly that. I replaced the stern tube. You may have to do that too.

I always had water in the rear bilge. When I hauled and drilled a small hole in the skeg it flowed for two days.

Stainless stern tube in concrete fill with stagnate saltwater is recipe for pitting of SS.

Moral of this story is go back with FRP stern tube

like this???

and that's not from collision damage just a bad spot after I ground all the gel coat off, it was easy to see...so I just kept grinding...

Psneeld

Strange you should have a picture of my boat draining the keel.

OB Thomas

Okay, thanks for the answers and they generated a couple of follow-on questions.
1. I have read that after the boat is pulled, you can test the stern tube with a plumbers pressure tester and plugging up one end of the tube. Is this a valid test?
2. Since I didn't want a boat payment, I paid cash for my boat. In doing so I have a reserve but it is a bit depleted. If I have a "leaky" stern tube can I wait until next season to replace it? Keeping in mind that I am not (currently) taking on amounts of water with this possible problem. I am not saying this isn't a priority, just a question of waiting to save up money for this.
3. In reference to question 2. I do all of my own maintenance except for the motor. If I haul, grind out the "false" floor, get the filling (whatever it is, i.e. concrete, foam, etc.) out myself to expose the tube, and prepare everything; what is an estimated cost to have a shop put in a new stern tube? I wouldn't want to work FRP or epoxy that is below the waterline as that is somewhat new to me.

I really appreciate the comments. I want to boat but it must be reasonably prudent to do so.

And thanks for the pic. Why did you grind it so much instead of taking out the end of the stern tube and going into it from above? I am guessing there was things in the way preventing access? Seems like much more work to repair the ground out keel versus maybe a couple of hole saw styled cuts? I am hoping to be able to access most of the keel from above if possible.

Jbear said:

Okay, thanks for the answers and they generated a couple of follow-on questions.
1. I have read that after the boat is pulled, you can test the stern tube with a plumbers pressure tester and plugging up one end of the tube. Is this a valid test?
2. Since I didn't want a boat payment, I paid cash for my boat. In doing so I have a reserve but it is a bit depleted. If I have a "leaky" stern tube can I wait until next season to replace it? Keeping in mind that I am not (currently) taking on amounts of water with this possible problem. I am not saying this isn't a priority, just a question of waiting to save up money for this.
3. In reference to question 2. I do all of my own maintenance except for the motor. If I haul, grind out the "false" floor, get the filling (whatever it is, i.e. concrete, foam, etc.) out myself to expose the tube, and prepare everything; what is an estimated cost to have a shop put in a new stern tube? I wouldn't want to work FRP or epoxy that is below the waterline as that is somewhat new to me.

I really appreciate the comments. I want to boat but it must be reasonably prudent to do so.

Click to expand...

yes it can wait...

depending on who you talk to and what boat...replacing the tube may never be worth it...

if you have room...a liner for the tube may be a better answer than replacing

yes..whenever you do the grunt work it really drops the price...however for some people with limited time, experience and the total equipment to do it, it may be cost wrth it to have it done.

some yards will cut it out...others have pressed it out (and say they would never do a job like it again)...some have coated it with a barrier coat. when the shaft comes out...you can inspect the tube with a camera (or an estimater can and let you know what's up in there.

Jbear said:

And thanks for the pic. Why did you grind it so much instead of taking out the end of the stern tube and going into it from above? I am guessing there was things in the way preventing access? Seems like much more work to repair the ground out keel versus maybe a couple of hole saw styled cuts? I am hoping to be able to access most of the keel from above if possible.

Click to expand...

Oh I didn't do anything with the shaft tube...that was just a bad spot I ground out to fix before I reglassed my entire bottom after fixing severe hydrolysis delamination and osmotic issues.

I elected to bury my head in the sand for a couple years thinking what's a couple more after who knows how many my keel was full of water. Next long yard period I may drill down from above and mount a drain plug so I can see if the keel fills and how fast.

I planned to never store my boat out of the water in freezing temps again so I hope water in the hull, keel, tube...etc..etc is less of an issue.

Jbear said:

... The shaft (drive) stuffing box drips as it should 2-3 per minute. There was indication that water may have been higher in the bilge at one time but the last time I dried the hull when I was scrubbing it out about 1 gallon of water came back in after 12 days or ...

Click to expand...

Do you really have a leak?

3 drops per minute = 180 drops per hour or 4,320 per day or 30,240 drops/week. There are about ~20 drops per teaspoon and 96 teaspoons/pint (8 pints/gallon).

Your stuffing box is leaking at a rate of just under 2 gallons per week.

Jbear said:

1. I have read that after the boat is pulled, you can test the stern tube with a plumbers pressure tester and plugging up one end of the tube. Is this a valid test?
2. Since I didn't want a boat payment, I paid cash for my boat. In doing so I have a reserve but it is a bit depleted. If I have a "leaky" stern tube can I wait until next season to replace it? Keeping in mind that I am not (currently) taking on amounts of water with this possible problem. I am not saying this isn't a priority, just a question of waiting to save up money for this.
3. In reference to question 2. I do all of my own maintenance except for the motor. If I haul, grind out the "false" floor, get the filling (whatever it is, i.e. concrete, foam, etc.) out myself to expose the tube, and prepare everything; what is an estimated cost to have a shop put in a new stern tube? I wouldn't want to work FRP or epoxy that is below the waterline as that is somewhat new to me.

Click to expand...

1. I think you could pressure test the stern tube if you can seal both ends of it.
2. Mine leaked for a couple of years before I fixed it.
3. Mine was removed by pounding it from outside into the boat. A foot at a time and cut it off inside the boat. The new tube was pounded in and sealed with MMM 4000. The yard said they never wanted to do a job like that again.

Larry M said:

Do you really have a leak?

3 drops per minute = 180 drops per hour or 4,320 per day or 30,240 drops/week. There are about ~20 drops per teaspoon and 96 teaspoons/pint (8 pints/gallon).

Your stuffing box is leaking at a rate of just under 2 gallons per week.

Click to expand...

This would not explain the water pressure up from the keel.

I was planning on hauling out to change the prop and look at everything anyway. I will get an estimate on pressure testing/evaluating the stern tube at that time.

Yeah, it isn't really leaking so much into the bilge. I only noticed a couple of drops of water when I stepped onto a section of the top of the keel (FRP) and it felt a little soft. So of course, being a guy I stepped down with all my weight and saw a couple of drops seep up from below.

I was in the bilge doing maintenance that the PO apparently didn't think was that important such as securing wiring, lubricating, labeling, and testing through hulls... you know, stuff that doesn't matter! When I went to install my Whale low-profile bilge pump to take care of the gallon or so that may come in each week is when I really noticed water passing between the keel section and my bilge. I of course informed the wife we may need to abandon ship but as it turned out, not necessary. I may have a bit of OCD but I don't like surprises when I am out in the Sound.

The Whale will keep any low level water out and I now have (3) 1100GPH main pumps installed in the two major bilge sections. Hate to hear the yards saying they would never do this again. If everything is cleared around the tube it seems like you should be able to cut/grind it out. But- never second guess this type of stuff. If everyone says it's a -itch it probably is!

Oh, and the water that came up from the keel was some of the most disgusting smelling water you could imagine. I asked the wife to clean it up but she declined. See how smart she is?!! ha ha

After I bought my boat I discovered it had water in the keel. I traced the source to 3 holes in the bilge that were securing a bilge pump. Glassed the holes and no more leak. To drain the keel I drilled and tapped for a pipe plug from outside. After 4 years of letting it drain while on the hard for winter it is finally dry.

psneeld said:

I elected to bury my head in the sand for a couple years thinking what's a couple more after who knows how many my keel was full of water. Next long yard period I may drill down from above and mount a drain plug so I can see if the keel fills and how fast.

I planned to never store my boat out of the water in freezing temps again so I hope water in the hull, keel, tube...etc..etc is less of an issue.

Click to expand...

I would strongly recommend AGAINST this head-in-the-sand approach to a potentially water logged and rotting hull. I would take seriously the potential for a catastrophic failure which could result from a minor impact. No bilge pump will be able to keep up with a 6 inch hole in your hull. Why run the risk?

Sounds like it's time for professionals to evaluate the situation and remedy the problem. Ignoring a potential hull breach is a recipe for disaster.

FlyWright- I agree. I am not saying I won't address the issue. I don't think the issue is a rotting hull either. I think the hull is completely intact. The issue is that there is simply water in the keel either from dripping down through the FRP in the bilge or up from a stern tube leak. If it is a stern tube leak, it needs to be repaired no question. If it is going down from the bilge because the shaft has been doing what it is supposed to by dripping water in the bilge for 44 years then maybe try to address that issue or not. The fact that there is water in the keel is not as much of an issue. Some boats have concrete, lead, or nothing in their keel. I was just trying to determine what others experiences have been with this. As I had said in an earlier post, I was going to pull the boat and see if they can pressure test the stern tube to see if it is the problem. I don't want to sink either!

jleonard said:

After I bought my boat I discovered it had water in the keel. I traced the source to 3 holes in the bilge that were securing a bilge pump. Glassed the holes and no more leak. To drain the keel I drilled and tapped for a pipe plug from outside. After 4 years of letting it drain while on the hard for winter it is finally dry.

Click to expand...

How did you discover? Is there a easy non destructive way to tell? I can't believe that an owner would be fond of the idea of drill a hole in the keel during a pre purchase survey.

Just an interesting thought...could ever a system kinda like a dripless be integrated into the shaft log/cutlass? I understand that the bearing needs water as lube but would some sort of sealed bearing work? Or maybe one with babit?

if the tube replacement is such an issue and there are thousands of these aging boats around it maybe an opportunity for someone to start making something.

FlyWright said:

I would strongly recommend AGAINST this head-in-the-sand approach to a potentially water logged and rotting hull. I would take seriously the potential for a catastrophic failure which could result from a minor impact. No bilge pump will be able to keep up with a 6 inch hole in your hull. Why run the risk?

Sounds like it's time for professionals to evaluate the situation and remedy the problem. Ignoring a potential hull breach is a recipe for disaster.

Click to expand...

When I discovered my hull issues a lot of damage had already been done...I repaired all areas of weakened glass and the whole hull was gone over with a fine tooth comb.

The head in the sand approach I meant was not knowing or caring if water was leaking past the shaft tube into the bilge or hollow keel...I haven't opened up the keel yet but ill do this spring in dry dock.

I called at least a dozen major yards that do this kind or work and several of the major fiberglass guys I know in South Jersey.

Turns out with my experience and research. ..I knew more than about half of them of the potential problems and possible repairs...the other half agreed with my future plans.

My head in the sand was not about the overall health of my boat just if the shaft tube is leaking.

Also remember a "professional" gave my boat a clean bill of health on a survey and within a year I had already stripped the entire porous gel coat off, a layer of hydrolyzed matt off the whole boat, filled maybe 50 major and 100 minor blisters, added 3 layers of roving and 4 layers of cloth to a 5x6 foot area...covered the whole bottom with glass/epoxy, drained the keel, and major repairs around both the stuffing box and external cutlass....let's just say that "professional" glossed over my hull inspection. The local glass guys thought I did a superior job for doing it myself outside.
During my repairs...sampling was done all over my hull and where I plugged 7 thru hull holes and removed several other items from the bottom...also wherever a blister was found it was ground to dry glass sometimes the holes were over 8 inches in diameter.

My guess is that my hill might be a lot dryer than most boats that have lived most of their lives in the water. Plus many stay just as wet wit some residual water in the bilge all the time which saturates a hull almost as fast in some cases.

Knock on wood...but the probability of my boat having a hull breach is pretty remote with the attention to detail I watch over the overall health of the boat.

eseyoung said:

How did you discover? Is there a easy non destructive way to tell? I can't believe that an owner would be fond of the idea of drill a hole in the keel during a pre purchase survey.

Just an interesting thought...could ever a system kinda like a dripless be integrated into the shaft log/cutlass? I understand that the bearing needs water as lube but would some sort of sealed bearing work? Or maybe one with babit?

if the tube replacement is such an issue and there are thousands of these aging boats around it maybe an opportunity for someone to start making something.

Click to expand...

The yards and pros I discussed my issue with said I was "overworrying" the issue...especially for boats that get hauled every year for the winter as long as the bilges and keel are drained as Jay did/does....

I had other issues to worry about first but now I will have some time to do the interior tap to the keel to monitor leakage and I believe I have the room in my shaft log to put a liner in so it's not nearly the big job that others have tackled.

psneeld,

I feel your pain. For as thorough as the survey was on other issues the survey did not even hint at anything about water in the keel. The reason I do most of the maintenance myself is partially my background of growing up on a farm and having to always fix everything coupled with engineering but also the "old very knowledgeable guys that care" techs are not around so much anymore. Now it seems about speed and getting money. I understand people need to make a living but here in Anacortes there are so many high end yachts that the local guys can charge pretty well for their work. I'll do the grunt work and educate myself to know what I have to have a pro do. I don't mind paying, and paying fairly for that work.

I also have other issues that require immediate attention. Apparently that week they wired the 110VAC on my boat in Taiwan the regular guy was out sick and his cousin was covering for him. When I went to change out to GFI circuits I flipped off the breakers and went to work. After getting tickled by a little voltage on the terminals I checked with my meter. I guess it made sense to someone to use the circuit breaker to break the AC RETURN instead of the AC LINE!!! So when I pop a circuit breaker I basically have an energized wire at my outlet, a ground, and a floating AC return! Oh yeah, missed that on the survey as well.

~ Jeff

eseyoung,
They make a moisture meter that can read through the FRG I think. They were able to tell me that the decks had apparent moisture. I can only guess if you place that against the keel it would also indicate if there was moisture in there.

I had an old sailboat that used open cell foam under the floorboards. It was also wet in the keel. I think the only answer is to open them up and clean them out so you can reach the water that will inevitably get to the lowest point. I am going to guess that there are a lot of boats out there with water in the keel that people don't know about.

Jbear,

I had a a leaky shaft tube as well. One fall I drilled a hole in the keel to let it drain. It was stlii seeping in the spring. The next fall I pulled the prop and shaft, made fittings and pressure tested the tube. You only need 3 or 4 pounds of pressure. It was leaking.

Then cut out the false floor and removed the stinking, discusting, revolting foam. Sazall is your friend. Once the foam was out used the sazall again on the fiberglass tube that looked like it was home made.

A quick web search found Nor'Easter Yachts Nor' Easter Yachts, Inc. - Custom Fiberglass Manufacturing - Milford, CT only 40 ish miles from me where I bought a new tube. Like you I was nervous about the installation so had the yard do it. Seaport Marine in Mystic, CT did a great job.

No leaks for the next few years I had the boat. I posted some pictures on a previous thread on this subject. PM me if you would like me to send them to you.

Rob

2 different ways to cover a bilge - with and without.

I’m sure that most of you have noticed that most of the trawler style motor yachts in the 38 to 41 foot range are similar on the interior and exterior.

I won’t go into why that is here.

The Jensen Marine 40 (built in the USA) is different and I”ll tell you how in one important way around the stern tube.

Unlike the Taiwan trawlers, including the DeFever 41, the 40 has no thin layer of glass covering the hollow keel cavity and forefoot voids. The Taiwan builders did cover them,in effect, making a sealed off tank with a top too thin for any structural use.

Jensen was a sailboat builder and those areas were never closed off in their sailboats. So why close them in a motor trawler? I talked to the 40 footer production line foreman and he told me the marketers from PassageMaker, Inc, wanted the bilge covered to look more finished. Mr. Jensen came down on the “leave it open” side.

For the most part these voids are empty, although in a few hulls they may contain some small amount of concrete ballast. Sometimes there are a few small bulkheads that support the shaft tube.

When asked by owners who see my engine room I tell them if they want the same arrangement they can do this

Saw the edge where the sump cover meets the inside of the hull and remove the problem ( Dermal or sawezall ). Once you open the area up you can really clean it and paint it and keep a good eye on it in the future. Leave the bulkheads - cut limber holes.To me it’s worth the piece of mind knowing I’m looking at the actual bottom when I lift a floor hatch after colliding with a water borne object.

Yeah a couple of days of hot and dusty work and probably too much for the average owner.

Keep in mind that there is virtually no limit to how a Taiwanese builder can deviate from normal practice.

YMMV

Mike

Ok. I have to ask. What is a stern tube?

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mbevins said:

Ok. I have to ask. What is a stern tube?

Sent from my Nexus 7 using Trawler

Click to expand...

What I am talking about is really a shaft log (stern tube is another name commonly used)

It's a tube that goes through the hull to form a watertight seal preventing leaking into the hull. It usually has the stuffing box at one end and a cutless bearing carrier at the outer end screwed on to it

wait. now i am confused. I thought that the term 'shaft log' referred to the bearing where the shaft exited the keel. So i know that is that bearing called? would that be considered a cutlass?

eseyoung said:

wait. now i am confused. I thought that the term 'shaft log' referred to the bearing where the shaft exited the keel. So i know that is that bearing called? would that be considered a cutlass?

Click to expand...

I think there's been overlap as new techniques and designs have come about,,,

The cutless that bolts to the back of the keel is actually a "bearing carrier or housing" and the cutlass bearing itself can be removed. On the inside, the stuffing box is usually clamed to a shot piece of hose that is in turn clamped to the inner part of a shaft log or stern tube. Sometimes the tube is nothing more than a tube of glass that is part of the yll and it's just a hole drilled through...on some boats it's a glass, bronze or stainless tube that has accessories to do different things screwed onto either end.

The picture is a "bearing housing" from Buck Algonquin..go through their catalog and see what names they give to the different parts as they have been around awhile...

the origin of the word "shaft log" comes from the heavy timber section that the shaft went through on wooden boats.....

eseyoung said:

How did you discover? Is there a easy non destructive way to tell? I can't believe that an owner would be fond of the idea of drill a hole in the keel during a pre purchase survey.
.

Click to expand...

Bought the boat in upstate NY Nov, and decided to leave it there for the winter.
In the spring as I was doing prep work to bring her back to CT, I saw water dripping out of the keel. Finally discovering that I could not seal it while it was leaking, I decided to put in a drain plug. Then I fiberglass repaired all the area from the outside.
During that summer I found the old screws in the bilge that held the pump. I looked there because a friend had a 36 Albin with water in the keel from poor fiberglass work inside the bilge under the engine. Mine was sound there so I started looking harder and found the screw holes.
I vacuumed them out, cleaned the area and glassed the holes.
Now there is no leak.

psneeld said:

What I am talking about is really a shaft log (stern tube is another name commonly used)

It's a tube that goes through the hull to form a watertight seal preventing leaking into the hull. It usually has the stuffing box at one end and a cutless bearing carrier at the outer end screwed on to it

Click to expand...

Thanks, the shaft tube I fully understand. It was the slang term that had me confused. Your definition is perfect by the way.

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