holes in bilge (not limber)

[mrtrawlerguy]

I own an 1986 Ocean Yachts Neptune. I has a dry bilge. I have noticed a couple of "holes" about the size of a quarter in the bilge over the keel. Since they were dry I had not paid much attention to them.

I recently had to replace the hot water tank and so there was a fair amount of water in the bilge. I pumped it all out and dried the bilge; however I noticed that one of the holes was weeping water. It did not taste of salt but had a strange smell like antifreeze etc. It keep weeping so I decided to put my wet/dry vacuum over the whole and let it run for an hour. I drew out about a gallon of smelly water. All the while the rest of the bilge is dry.

What are these holes for and where is the water coming from. The keel is not bolted on but is part of the fiberglass hull.

Any answers to this would be very much appreciated.

 

[Lutarious]

Pictures would help

 

[Xsbank]

Like my Grand Banks, the keel is probably hollow and/or filled with ballast. The ballast is usually old bits of metal and other crap that was lying around in the shipyard. Grand Banks put in a hose with a cap so you could pump it out if it ever got water in it (mine had a stainless strip screwed to the stem and the holes leaked, filling the keel). I would try using a drill pump in one of those holes to see if your keel is empty.

 

[Forkliftt]

I own an 1986 Ocean Yachts Neptune. I has a dry bilge. I have noticed a couple of "holes" about the size of a quarter in the bilge over the keel. Since they were dry I had not paid much attention to them.



I recently had to replace the hot water tank and so there was a fair amount of water in the bilge. I pumped it all out and dried the bilge; however I noticed that one of the holes was weeping water. It did not taste of salt but had a strange smell like antifreeze etc. It keep weeping so I decided to put my wet/dry vacuum over the whole and let it run for an hour. I drew out about a gallon of smelly water. All the while the rest of the bilge is dry.



What are these holes for and where is the water coming from. The keel is not bolted on but is part of the fiberglass hull.



Any answers to this would be very much appreciated.

Mr Trawler Guy,
I have a similar setup it seems on our Present 42. There is actually a "sub floor" of sorts that appears to be the bottom of the bilge, but I had noticed that a few older existing screw holes seemed to penetrate this. Occasionally I would wet vac the "bilge" and still see water below the screw holes. A couple of years ago I bravely drilled a test hole and turns out that there is a cavity about 4-5" tall above the keel that appears to run much of the length of the boat. Always chasing bilge odors as I was, I went on to cut a plug out and vacuumed probably 20-30 gallons out as I recall.
About a year ago I cut an access "square" out of the FG floor and used an aluminum bracket I built to lower my bilge pump into this area permanently. Everything has worked fine, BYRMV!!


1983 Present 42 Sundeck
Twin Lehman 135's

 

[mrtrawlerguy]

Great Replies

That you for your excellent replies! Not only were they insightful but fast. In the next couple I'd days I will take a picture and post it. The answers lead me to another question - is there any harm in water that gets INSIDE the keel, staying in there? Also I have been wondering if I set the vacuum to blow into the keel, instead of suck water from it, would I be forcing the water that remains in the keel where I don't want it or would that lead me to see or hear where the water is getting in.


Interesting situation. Guess that is one reason we like boats - they can be very complicated and vexing?

 

[dwhatty]

Water left down in there in a boat located in Northern climes can freeze and cause damage. I know from experience.

Took care of this by installing a bronze drain fitting (from the outside) at a low point in the keel. After the boat is hauled for the winter I remove the plug and water seeps out of the concrete ballast through the plug hole for several days thereafter.

 

[cappy208]

I have this same situation in my bilge. The aft 12' of keel has cement ballast. There are two points which have permanent depressions. I liken them to sumps, to catch engine slop in one, and the bilge 'low point' in the other.

The problem is (IMHO) that water sitting there absorbs INTO concrete, making it subject to freezing expansion and contraction.

Your situation sounds like a fiberglass cap was put over the original ballast, and the ballast has subsided down (probably from a bad pour of ballast) leaving the void. I would suspect as was mentioned, opening up the void and keeping it dry would be desirable. If the ballast has subsided, then you have a situation of failing (loose) ballast. Not necessarily a bad thing, but certainly an indication of water in a space where the temperature can cause havoc.

Do you store you boat in a heated inside storage?

 

[READY2GO]

Quote from mrtrawlerguy "The answers lead me to another question - is there any harm in water that gets INSIDE the keel, staying in there?

Yes there is. We just spent 5 weeks in a boat yard doing a bottom job and many other things. We found that our keel had a lot of blisters on it. Some were very deep. We finally figured out that the keel was hollow and full of water, as someone has already said there is a false floor in the bilge. The keel had been full of water for who knows how long. We drilled holes and let the keel drain. I then took a holesaw and put 2" holes about 4' apart in this false floor and let the area dry out for a couple of weeks. I then bought closed cell two part expanding foam and began at one end and filled the hollow keel. Once the foam was fully cured I then fiberglassed over the 2" holes. Now there is no place for water to sit and cause blisters.

Hollow keel.



Foam being installed.



Hole ready to be filled.



Two gallon kit was just the right amount.

 

[Donsan]

You might want to review the recent thread on ballast. If recall, there was a discussion of a water cavity in the keel that is used as ballast on some Taiwanese boats. You may have just drained some or all of your ballast.

 

[psneeld]

I had/have water intrusion...but never have heard of water in a TT for ballast...

And with the research I did on my keel...I'm pretty confident...most people that have had it found a way to get it out.

Though I admit there may have been the odd one(s) out there.

I just doubt it based on there's no baffles in there on any I have seen.

 

[READY2GO]

You might want to review the recent thread on ballast. If recall, there was a discussion of a water cavity in the keel that is used as ballast on some Taiwanese boats. You may have just drained some or all of your ballast.

I would think that if it was designed to have water ballast that it would be designed not to cause hull blisters ie some sort of barrier coating. I would think that it would also have some means of draining the water for those in northern climates where boats are pulled for the winter. I don't think letting a cavity full of water freeze would be to good on the hull integrity.

 

[psneeld]

I would think that if it was designed to have water ballast that it would be designed not to cause hull blisters ie some sort of barrier coating. I would think that it would also have some means of draining the water for those in northern climates where boats are pulled for the winter. I don't think letting a cavity full of water freeze would be to good on the hull integrity.

Lots of reasons not to do it....

 

[Donsan]

Sorry, the discussion may have mentioned ocean going ships and not pleasure yachts.

What would the cavity be for?

 

[Duvie]

I have seen some downeast boats that use water in the keel section for ballast.They are voids that fill up when launched and have open drains that drain when hauled.

 

[Forkliftt]

Quote from mrtrawlerguy "The answers lead me to another question - is there any harm in water that gets INSIDE the keel, staying in there?

Yes there is. We just spent 5 weeks in a boat yard doing a bottom job and many other things. We found that our keel had a lot of blisters on it. Some were very deep. We finally figured out that the keel was hollow and full of water, as someone has already said there is a false floor in the bilge. The keel had been full of water for who knows how long. We drilled holes and let the keel drain. I then took a holesaw and put 2" holes about 4' apart in this false floor and let the area dry out for a couple of weeks. I then bought closed cell two part expanding foam and began at one end and filled the hollow keel. Once the foam was fully cured I then fiberglassed over the 2" holes. Now there is no place for water to sit and cause blisters.

Hollow keel.

View attachment 35219

Foam being installed.

View attachment 35220

Hole ready to be filled.

View attachment 35221

Two gallon kit was just the right amount.

View attachment 35222

Great pictures and info.


1983 Present 42 Sundeck
Twin Lehman 135's

 

[Greatlaker221]

Yes cold weather can cause damage!

I have been dealing with the keel problem for a few months now. I have had to re build the entire bilge. Hershine used concrete for the entire length of the keel. Under the stern tube, there is a hollow area. That held water and when frozen eventually cracked the keel and the water found its was both in and out.

I have documented the process here:

Saving Tortuga: Water in the keel

 

[Forkliftt]

VERY nice work Great Laker, a great resource for the board!


1983 Present 42 Sundeck
Twin Lehman 135's

 

[READY2GO]

Very nice indeed. I checked out your blog, looks like you are doing a great job on the restoration. I am jealous of the inside storage for working on the boat. We just spent 5 weeks in a dirty rainy boatyard.

 

[Greatlaker221]

Thank you all. It's a lot of work, but nice to be inside in WI. It cost a bundle but necessary to get the stack of projects done by spring. Watching your great job on the thruster is tempting me!

 

[Donsan]

Thank you all. It's a lot of work, but nice to be inside in WI. It cost a bundle but necessary to get the stack of projects done by spring. Watching your great job on the thruster is tempting me!

I enjoyed your blog also. It kind of got me thinking about my fuel tanks. They are original and 30 years old. Our survey didn't turn up anything but I have read a lot of horror stories and the surveyor can't readily see the top of the tanks. Did you have your boat surveyed? I certainly hope you got a really great price on it.

 

[READY2GO]

Thank you all. It's a lot of work, but nice to be inside in WI. It cost a bundle but necessary to get the stack of projects done by spring. Watching your great job on the thruster is tempting me!

I used the thruster for the first time yesterday (other than just playing around). I had to pull into a canal do a 180 and then dock in front of two boats rafted at the dock which made it even tighter. The thruster worked great and made the job easy. The rudder modification was also a big success. It was well worth the $900 as the boat handles fantastic now. I would recommend it to any one with a single screw TT.

 

[deepsix]

I notice that later in the season my keel fills with water and maybe its my imagination but the boat seems more stable. Should I keep this filled with water ? Will bleach(to prevent alge) damage the glass?