removing the lead keel?

[Bare Aweigh]

My 1987 Oday 28 has an external lead keel that is weeping at the seal with the bottom of the boat. I had the keel bolts tightened to see if that would help. Five of the bolts were tightened about a 1/2 turn, but one of the bolts came up about an inch before suddenly stopping. After tightening I filled the bilge with water to checked for leakage. Fresh water is now weeping from the seal above the keel.

I think I need to drop the keel in hopes of finding out what's going on. Has anyone encountered this kind of problem before??

Any thought's or experience would be appreciated. I think that dropping the keel, cleaning and re-bedding is fairly straight, but I still need to figure out the loose keel bolt.

Mike

 

[Jim]

Here is what I would do

First find out for any ODay groups if there is any wood rotting in the keel stub. This then becomes a much bigger job.

Second, with the keel and boat supported, remove the nust and washer and caulk around them with 3M-5200.

Third, put the nuts back on a tighten them up.

The remember my saying, all bolted on keels leak, it is just a question of how much.

When the boat is in the water, dray of the bilge. Spray foaming bubble cleaner around to look for leaks. Get a good idea how fast the water is coming in. Consider a second bilge pump and / or high water alarm if it comes in too fast.

 

[Maine Sail]

The problem of...

The bolt rising up an inch or so as you tightened it could be a failed bolt due to crevice corrosion. It could also be that O'day was one of the manufactures who laminated plywood into the keel stub and this wood is compressing giving the appearance of the bolt rising.

Either way dropping the keel and re-bedding it is no simple task. Unfortunately what you will likely find is that the diameter of teh bolts has been eaten away and your keel needs new keel bolts installed. Mars Metals up in Ontario is one of the few shops who does this the right way and you can drop your keel and ship it to them on a pallet and they'll ship it back to you.

I have to disagree with Jim that all keel bolts leak as I have seen a fair share of 30+ year old keels dropped and re-bedded, due to a grounding, that had ZERO crevice corrosion or previous signs of leaks. If your keel bolts are leaking they are also being eaten away as in the picture bellow by crevice corrosion. The only sure fire fix for this is a total re-set with new bolts if the crevice corrosion is too bad.

 

[Jim]

Sail Maine, the question is how much they leak...

The leak doesn't even have to make in into the bilge before being evaporated. There is no way the caulk can hold up for year with the boat being stored on the hard, soft and hard groundings and cold weather. They have to leak, the leak may not even make it into the bilge but, it has to be leaking.

The permeability of fiberglass, gel coat and even caulk allow water migration to some extend, therefore technically all boats leak.

 

[Maine Sail]

How does..

water evaporate under water? Trust me there are many keels not leaking. If you haul your boat and no water comes out from the joint it's probably dry. If you haul it and months later it looks like the photo bellow it's leaking.

P.S. When we dropped the keel on my old Catalina 30 over 80% of the surface had ZERO water intrusion. Only the areas where the plywood core was were wet and the solid glass portions were bone dry. Also the keel bolts, where the plywood core was, were leaking and almost gone from crevice corrosion the other perfect as new. We literally had to cut the keel off the boat and jamb wedges in between to get it apart. The 5200 failed due to too much moisture from the bilge side and became almost brittle where the leaks were. Where there were no leaks it was still somewhat pliable.

 

[Maine Sail]

Another photo

This keel bolt was leaking from the top or bilge side and NOT the keel side. Note the lower portion where it passed through the keel stub was free from corrosion. Perhaps this boat had a wet plywood core from bilge side leakage that destroyed these bolts. The point is that the keel side is not what failed but rather the bilge side.

Sometimes plywood cores are destroyed by owners mounting a new bilge switch. Perhaps they don't realize or know it is a cored bilge so they don't bed the screws and the plywood just sucks up the water eating away the keel bolts..

 

[bffatcat]

All Keels Leak ??? I disagree

Ive got a 1975 Pearson 26 weekender The keel dosent leak a drop. This is my 10th
season with this boat and it never leaked. If it does not rain my bilge is dusty
dry. If it rains there is maybe a couple of sponge fulls of water in the bilge.
fresh water never salt.

My keel bolts are galvanized and coated with epoxy. They are right on top just under the bilge boards and easy to inspect. They look the same as when I bought the boat 10 years ago. NO rust anywhere. In the spring before I paint the bottom I check the 5200 along the seam for cracks, scrape out anything thats loose and apply fresh 5200. More often than not there is nothing to do along the seam.

1975 p26w whitecap hull #76 Marblehead MA

 

[Dave Groshong]

test

test

 

[Tim R.]

Mine doesn't leak either

Taped and faired the whole keel right up over the seam and you would think it was internally balasted. Foss specced out the fairing and the local boatyard did the work. Never any signs of leaking. The result is a boat that can outpoint others boats of the same design.


I love it...water evaporating under water. Not trying to pick on you JIm, but we either misunderstood you or you drank your lunch today;-)

 

[Jim]

Caulk fails

They all leak to some extent. You might not be getting water in the bilge but the keel bolt and/or joint is getting wet somewhere. I never meet any caulk that didn't fail, so unless your recaulking every year (still could fail), it leaks.

But what you can't see leaking, isn't. Right?

That is why I like the Compac 35 or an Island Packet keel design.

 

[Jim]

RE Another photo

Ice might have caused the caulk to fail. If it wan not leaking from the bottom the bilge must have been dry. I would guess rain water or AC drip cause the corrosion.

Never meet caulk that didn't fall!

 

[Maine Sail]

Jim perhaps...

you can tell your same theory to the New England Aquarium who relies on silicone, which is considerably less structural, to keep hundreds of thousands of gallons from leaking into the building every single day and at much higher PSI than your keel joint sees 18" bellow the surface. What about the drain in my sink bedded with plain old plumbers putty that has an 18 pound disposal with 1.5 hp motor and the associated torque that is also not leaking or the plumbers who use non drying caulks called pipe dope. Many of these system withstand 300psi and up your keel might see 3 psi... On and on and on...



I will agree that many keels will eventually leak if not properly cared for but also many don't. None of my seacocks leak either hmmmm....

 

[Maine Sail]

Using your premise...

Quote: "Never meet caulk that didn't fail!"

Then you really should be concerned about what looks to be a Catalina in your avatar. Catalina's along with most other new boats, other than a few high end builders, use "caulk" to adhere the "pan" or "structural grid" to your hull. You're entire boat as well as many, many others I guess are going to fail...


I've seen just the opposite as you. I've seen many situations where the caulks or sealants worked unbelievably well. Many failures of caulks and sealants can be directly related to improper use or application.

Even with a leaking keel joint, due to substandard build practices namely plywood laminated into the keel stub, the keel still required a sawzall and large oak wedges to remove it.

Keels have a unique way of letting us know if they are leaking they will show water along the external seam.

Keeping a dry bilge is a great way to make sure your bolts are not leaking or suffering from crevice corrosion.

 

[Don S/V ILLusion]

Actually it will fail at some point

I wouldn't be too hard on someone who says it will eventually fail as he is probably correct, particularly with respect to non-adhesive "caulks" if one defines "caulk" as something which aides in forming a structural bond as well as those which do not stay flexible. Many boat builders including Catalina use non-flexible adhesives as well such as the not so venerable 5200 which can eventually fail under sheer stress and flexing.

 

[Maine Sail]

Don..

I responded to a post that has apparently disapered and actually quoted from it in what is now post #2 it used to be post #3.

I agree 100% that bolt on keels will eventually leak and also that fiberglass hulls will eventually wear out. We have many old and early fiberglass boats up here in Maine many with externally mounted lead that is still going strong and dry.

The original quote did not mention eventually just that "all keels leak"...

 

[Don S/V ILLusion]

got it

I tend to read things too literally. Some of the older adhesives were good and then only served to fill a seam rather than do any structural work. My old 27 footer had 3 times the number of keel bolts my present 40 footer has..... and they were bigger too!

 

[Maine Sail]

I know what you mean...

The keel bolts on our current boat are honkers too. And they still look damn good for almost 30 years old!!

 

[Jim]

Sail Maine, I know this all too well!

Sail Maine I strongly disagree caulk fails! Why else do we re-bed chainplates?

The keel joint is a high stress area just like the chainplates. I just had the caulk fail on the starboard mainsheet pulley behind the mast. I must admit the penetration was not drilled correctly and Catalina filled it up with soft caulk. I am going to end seal this area on the hard. I have seen lot of Catalina with this problem. I think most owner don’t know they have water in the core.

I do keep my bilge dry, except the compartment forward of the mast, with no access without removing the floor. If there is no rain my bilge is bone dry.

I am sure that the caulk will work fine as glue in the Catalina bonding system. We are talking about water penetration.

 

[Ross]

Modern caulk is durable! A caulked joint fails

when the movement is greater than the elasticity of the caulk. Most modern elastic caulks can allow 50 percent joint movement. If the joint is poorly designed so that the caulk is too thin or if it is poorly fastened the caulk will pull away from one surface. This is not a caulk failure, it is a joint failure. My 50 year old Grumman canoe has riveted seams that are bedded in a caulk/sealant and it has never leaked. If the keel joint leaks it is because the joint has failed either because of poor design or damage but never because the caulk has aged beyond its useful life.

 

[Maine Sail]

Ot often fails...

because the caulk is used WELL beyond it's flex capabilities. You're blaming caulk when many times it's installation or application errors.

Take a Catalina for example (owned three). The bulkheads are screwed inn not permanently glassed to the hull and deck, and the hull and deck are screwed and then bolted together only about every 24" or so. This design leads to movement between the deck and the bulkhead to which the chain plate is usually bolted.

The chain plate goes through the deck with no bevel in the deck to create a thick enough gasket to work with the movement associated with a "screwed" bulkhead design. If you use a sealant that can flex sufficiently to allow the movement associated with the chain plates it would work better. Unfortunately tere are very few sealant/caulks that can withstand 700%+ movement of 1/64th of an inch bead of sealant.

Another reason for failure is the improper or undersized use of backing plates on high load items which allows movement and eventually compression of the core.

On our current boat it was bedded 30 years ago using butyl tape and the chain plates are still bone dry having never been re-bedded. As a matter of fact the majority of our boat has not been re-bedded and is still dry (proof see photo bellow of a 30 year old factory bedded genny cleat that I removed). I've checked them each spring and just checked them again during a rain storm & after a good day of 20-25 knot wind sail. Still dry. Caulks will fail if used outside their range of flexibility. There really should be little to no movement in a keel joint and chain plate is different depending on the design.

Another reason folks assume caulks fail is that many owners have used silicone along the way. If you try to bed say 4200 over a previously sealed deck fitting done with silicone it will peel from the substrate..


I don't want to hijack any more of this thread. If you want to discuss bedding & caulk please create a new thread and we can discuss best practices and the merits / pit falls of caulks in certain locations. It's a very good topic that is under discussed.