Keel concerns

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John Vergis

Member
Joined
Oct 11, 2020
Messages
6
Location
United States
Vessel Name
Acacia
Vessel Make
1983 Nova Marine 42 Sundeck
I bought a 1983 Nova Marine 42 sundeck. I bought it about a month ago and of course it is in storage now since I am in Cleveland ohio. The marina who is storing the boat for me was concerned that my keel does not have a drain plug. He said that it is possible for water to get down into the hollow keel and freeze and crack it. Has anyone experienced this problem? The bilge seems to be made well to where there is no cracks for water to get down into the keel so I don't see much of a concern but what is everybody's experience on this? The mechanic at this Marina wants me to drill a hole into the keel and see if there was water in it, and if so, drill bigger hole and install a proper plug. Thoughts?
 
My keel doesn’t have a drain either. I have been think about drilling a hole but haven’t decided either way yet. My issue is there isn’t room for a drain plug as the keel is very narrow in the rear.
 
Well I have plenty of room for a hole but I can't decide. I hate putting a hole in something when it's not necessary.
 
The inside bottom of my boat has any number of holes in it. Bilge pumps, float switches, battery tie downs, etc. Also there is generally some water in the bilge. Careful inspection shows no sign of leakage or splitting. I have often considered a drain hole but just don't like the idea, although I have seen numerous boats with plugs in them.

pete
 
Plug? Or risk freezing and breaking the keel? Seems simple to me.
 
2 gallons of freeze ban should do it.
 
You can always go inside and drill a hole and see if there is water or not. Then either plug the hole, glass it closed or put an access plate on the hole.
 
Over the winter many boats will have a deck, cockpit or other leak, if the water can get into a hollow keel there is a danger when freezing.
 
Greetings,
Mr. JV. Welcome aboard. I with your mechanic. Drill a hole. What's the worst that could happen? Water? Then that answers your question AND also makes the decision to install a drain plug. No water? Not hard to properly patch a small (1/2"?) hole.


Even though your bilge area LOOKS leak tight, there are several potential areas of water ingress. Shaft log, unseen cracks/holes, penetrating and improperly sealed fasteners are ALL potential leak sites.
 
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Don't know how to link - but see my post 23 May 2020 "Keel Full of Water" - 1989 Nova Marine 37ft Sundeck; essentially the same boat and same issue.
New to us boat last year, when removing bilge pumps and float switches fastened to and through the bilge floor we noticed "mystery" water was bubbling up through the holes in the bilge floor. Drilled a larger hole through the bilge floor to investigate and removed 30 or 40 gallons of smelly water from the bilge. As we boat in fresh water we can't be sure if the water is coming in from the exterior or through holes in the bilge floor somewhere.
Don't know how many years the water may have been there, but likely for several well below zero Canadian winters. No sign of any external keel or internal bilge damage, so clearly the keel can accommodate a substantial amount of frozen water.
This spring we removed everything that was accessible and fastened through the bilge floor before launching this summer; sealing up the holes.
This fall again drilled an investigation hole through the bilge floor and took out only 5 or 6 gallons of water. So either we have slowed down leaks through the bilge into the keel, or what we removed in the spring was many years of accumulation.
Have yet to make up our minds to either install a drain in the base of the keel, or install a threaded/plugged access hole through the interior bilge and just pump and drain as part of the fall winterization routine. Leaning towards an access hole in the bilge to avoid the risk of an unseen lost or leaking keel drain during the boating season.
Chris.
 
CPD, is there a fill-it-with-foam option?
 
CPD, is there a fill-it-with-foam option?

Have seen posts of folks considering foam or even cement, but I would be concerned of not knowing the specific construct inside the hollow keel. If there are baffles or partial bulkheads one might not be certain to have fully filled the cavity - resulting in the same end risk of trapped frozen water. We will be carrying on with the hollow keel, and drain every fall when winterizing.
 
Don't know how to link - but see my post 23 May 2020 "Keel Full of Water" - 1989 Nova Marine 37ft Sundeck; essentially the same boat and same issue.

https://www.trawlerforum.com/forums/s3/keel-full-water-50926.html#post881849

Have yet to make up our minds to either install a drain in the base of the keel, or install a threaded/plugged access hole through the interior bilge and just pump and drain as part of the fall winterization routine. Leaning towards an access hole in the bilge to avoid the risk of an unseen lost or leaking keel drain during the boating season.
Chris.
This latter approach appears to me to be the safest and most logical CPD. In other words, keep doin' what you're doin'.

Note I have posted the link to your first post above. To do this you just open the post, copy the URL in the top window, then paste it in the thread post.

Cheers,
 
Then the foam would get waterlogged and you wouldn’t be able to get the water out at all.

I am not a foam expert, but there is such a thing as closed cell foam. I would not want to put up with whatever the contained water is doing to the fiberglass (think blistering from within). Minor surgery to the keel to discover the internal structure or even a sonogram might resolve doubts before drilling multiple holes to completely fill the keel with "waterproof" foam or whatever followed by glassing over the holes would be my plan.
 
Well I think I have heard enough on here. I think you guys have convinced me to drill a hole and put in a plug. Like one gentleman commented on here, it's a lot cheaper than a cracked keel. Thank you everyone for your comments.
 
Mine was hollow with no partitions....easier to put a drain plug near the bottom and drain prior to winter storage.


I didn't as I only found the water after the winter.


My second thought 7 years ago was to do the plug from the bilge so I could inspect, pump dry even while in the water. Still haven't gotten around to it.


The first pics are my boat...the last was from a guy who replaced his shaft log.
 

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I am not a foam expert, but there is such a thing as closed cell foam. I would not want to put up with whatever the contained water is doing to the fiberglass (think blistering from within). Minor surgery to the keel to discover the internal structure or even a sonogram might resolve doubts before drilling multiple holes to completely fill the keel with "waterproof" foam or whatever followed by glassing over the holes would be my plan.

Yes there are closed cell foams but you probably would not be able to get if filled completely and would still have pockets that could hold water and freeze. I am going to put a drain plug in the bilge so I can get a look in there and see if there is water or not. Our boat has gone through 4 winters here so it is probably ok. But I think I want to look.
 
Hollow keel? I must admit being completely ignorant of such a thing. I thought all keels were filled with ballast (lead, concrete or iron) and subsequently sealed. But then I've only owned sailboats and full displacement trawlers.

Is this something that is common on semi-displacement or planing hulls?
 
I suggest a reasonable sized inspection port then use a shop vac to clean it out. A drain plug would have to be on the very bottom to fully drain but that would be vulnerable to grounding.
I would also want to know how the water gets in the keel.
 
Ok, this thread got me motivated to find out what was inside my keel. I went inside and drilled a 1/4” hole in the false bottom of the bilge. Immediately I heard a hissing sound. I don’t know if it was suction or pressure but as soon as I heard it I knew that there weren’t any leaks or else the air pressure or vacuum wouldn’t have held. Then I took a 1” hole saw and drilled the 1” hole for the drain plug. After drilling the 1” hole I stuck a 3/8” wooden dowel down into the new hole to see how much water was in there. It went in about 4” and hit a solid bottom and no water. So the exercise was a waste of time and now I have to caulk in the drain plug. But at least I know there isn’t any water to freeze...
 
I've got a plug in my Monk36. I think its a good thing. of course you can argue that since 1983 it hasn't been a problem?
 
drain plug

my 1987 senator 35 has a drain plug, i pull it in the winter when the boat is on the hard , last year about a quart of water came out. the plug is located on the rear of the keel, just below the drive shaft. mine is a single engine.
if yours is a twin i would put the plug as low as possible on the keel but facing the rear to protect it.
 
My keel narrows down at the rear so there isn’t room for a drain plug.
 
I think I posted this once, so my apologies. My GB32 had a hollow keel. GB put a hose, modded into the bottom of the bilge so you could pump out the keel. Mine continuously filled with rusty water. Turns out the space is full of scrap-crap. I had noticed that the stem had a nice stainless trim screwed on to it, the screws looked suspect. Sure enough, one screw was missing about a foot above the waterline. I removed the trim, sealed all the screw holes and reattached the trim piece, dry keel ever after. Underway, the water raised in front of the stem would push water into the small hole which would then migrate into the keel. Never did find out where the entry to the keel from the bilge was but I stopped it, no more pumping out the keel.
 
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