Keel Bolt / Stud Leaking

[neilpride]

Plexus is not flexible , so I doubt very much that with just retorque aft keel bolt you can go away that easy, I mean , plexus is like a epoxy putty , hard... in the safety sheet of plexus maybe you can found the melting point of the material or any other indication to make life easy if you need to remove it... I guess

[Paws]

I would absolutely retorque before doing anything else. Given the age its entirely possible the bolt was never tightened down in the first place. Given the damage you will do dropping the keel I don't see that you have much to loose. I would tighten it properly and see what happens for the next few months.

John

[donradcliffe]

First, is your boat in fresh water?? The picture shows an amazing lack of rust/discoloration if its a saltwater boat and its leaking at the keelbolt.

Second, give the stuff around the edge of the washer the fingernail test. If you can dent it with your fingernail, its flexible like 5200, etc. If its hard like epoxy, it could be Plexus.

[Harry Brown]

The leak has just happened hence the lack of corrosion on the stud.
It is in salt water. The yellowish stuff around the washer is hard, I'm pretty sure now that it is Plexus MA 310.
I have just been researching it and Plexus is a substance used for keel/hull bonding and use around keel bolts (as we can see).

[JPA Cate]

Harry,

I'm not going to make a recommendation here, having never had anything to do with Plexus. Maybe send minaret a pm and see if his advice is the same as neilpride's. You really do need someone with Plexus experience so that you can find out what to avoid.

I hate to add to your concerns, but you might want to find out how they isolate the iron in the keel from the salt water, too. I have seen what happens if you do get saltwater intrusion, and let's just say, you really don't want that!

Good luck with this project. When you ask for advice, ask about the possible downsides of re-torquing that one bolt. If it was never properly tight, that's one thing, but how will you know, unless it is finger-loose? Furthermore 360 n/m is about 266 foot/lbs., torque, and that is more than my torque wrench goes!

Like I said, good luck with it!

Ann

[Harry Brown]

Originally Posted by Paws

I would absolutely retorque before doing anything else. Given the age its entirely possible the bolt was never tightened down in the first place. Given the damage you will do dropping the keel I don't see that you have much to loose. I would tighten it properly and see what happens for the next few months.

John

So tempted John, so tempted......
I'm going to see what happens over the next few days/weeks with regards to information received and make an informed decision...

[neilpride]

I never see Plexus before on keels , I see lots of this stuff in bulkheads installations, decks, tanks, grids etc... I don't know why they use it on keels, the norm is to found a hell of 5200 or other similar stuff like sika , 4200 on keels, I even see a keel hanging with just a bead of 5200,,, I don't see how plexus can copy with flexing and torsional , lateral loads, or even a groundings without cracking since the stuff is rigid,, I see some plexus cracked in bulkheads, deck flanges, even a partial debonding in a master main bulkhead,,, Minaret could have a better answer, I be very interested in see the outcome ..... one way or the other you need to stop that leak and try to keep the stud dry, no water infiltrations there since those fin keels are prone to get corroded aft keel bolts if you don't stop and correct the issue properly, yes is a $$$ bill to drop the keel , that's why many cruisers make mistakes in the keel hull joint area, goops of 5200 outside , retorquing bolts to see leaks showing up in short order, etc... is up to you , don't take by granted any Bavaria response my advice,,, ask around and see if the answers macht with each other,,,, good luck .....

[ontherocks83]

Just out of curiousity where are you located? There might be a member willing to give you a hand when the day comes to do the job. On the other hand they also might just want to bring some beers and see what happens

[minaret]

If its Plexus, dropping the keel could be a bear. Consider haul out, dry out, make special tool with correct size hole saw welded to pipe, bore around keel bolt with special tool, dry out and rebond/rebed.


That's if it's a stud or J bolt, if its a bolt threaded into an iron keel then it's no big deal, just haul out, pull it, dry it, rebed it.

[unclemack]

Compressed air could help find the exact place on the keel/hull joint where the water is entering if you think that might be useful.

Remove keelbolt nut and washer, clean area, large loose-fitting rubber washer over stud, metal pipe big enough to go over the threaded part is forced down on to the hull and sealed by the rubber washer, connect airline.

Someone at the keel watches the seam for bubbles and marks the area. Out of the water dishwashing liquid+sugar+water makes good bubbles. Finds gas leaks too.

It might be that injecting sealant from outside and then paying over the seam, maybe even with Plexus, would work.

Not much lost if it doesn't work as long as the hull isn't of cored construction anywhere near the keel.

[misfits]

The boat is 2007 & the leak is intermittent. If the keel is "bonded" to the hull with Plexus why not just back the nut & washer off. Dig out any sealant if you can, stuff as much butyl tape as you can push between the stud & opening or something like Life Caulk, reinstall the nut & washer, torque it & see what happens.


I know butyl isn't supposed to be used underwater but seems like an awful amount of Sabres have their keel bolts bedded that way. Doesn't keep the water out of the hull to keel joint but it does protect the stud. The 360 number for torqueing, can't be foot pounds, you'd spin the stud right out of the keel.

[Paul J. Nolan]

Originally Posted by Harry Brown

I'm a little bit disappointed with their response really.

Now there's an understatement!

Unless the boat has been damaged through bad seamanship, in my opinion it is not unreasonable to expect twenty trouble-free years at least from keelbolts and the keel itself. You don't need a boatyard, you need an attorney. The builder should be held liable for the cost of this repair.

Paul

[Paul J. Nolan]

Originally Posted by Paws

I would absolutely retorque before doing anything else. Given the age its entirely possible the bolt was never tightened down in the first place. Given the damage you will do dropping the keel I don't see that you have much to loose. I would tighten it properly and see what happens for the next few months.

John

I'm not a naval architect or even an engineer, but I see water seeping from a keelbolts as akin to discovering a mass in one's neck. It must be thoroughly investigated. A bandaid won't do.

Paul

[Frankly]

No experience with Plexus but I have reinstalled a keel. You didn't identify the keel material and it may not really matter. If it is cast iron then the stud is probably just threaded into the top of the casting. Since it looks to be in pretty good shape I would first try to remove the nut and then the stud. If you can get the stud out then run (don't walk) and get a 316 SS replacement. I would then clean and dry the hole as best possible, fill the hole (glass and keel) with epoxy and screw the stud back in place. Hopefully this will allow the epoxy to seep into any voids. Before the epoxy sets put the nut and washer back and torque the nut.

If this is a single stud on the rear of the keel, then its purpose is more cosmetic than structural. Get a copy of the Gougeon Brothers on Boat Construction (West System) and read the section on bonded keel bolts. The book is now available free on line.

I debated a long time about how to reinstall the keel (cast iron with studs on a 30 ft Hunter). In the end I used a thickened mixture of West epoxy buttered on the top, dropped (set really) the boat back on the keel, torqued the bolts,
used the squeeze out to fair the mating surfaces, and called it done. That was 20 years ago and even with some hard groundings no leaks so far.

Even if you can't remove the stud, I would still try the epoxy fix. At least epoxy will revert to a liquid with heat, not sure what Plexus will do.

IMHO getting a good fit between the two mating surfaces is a critical part. The epoxy fills the bill in that respect. If you end up dropping the keel and mess up the surfaces on the keel stub epoxy will be your friend for reestablishing good mating surfaces.

[Paws]

Originally Posted by Paul J. Nolan

I'm not a naval architect or even an engineer, but I see water seeping from a keelbolts as akin to discovering a mass in one's neck. It must be thoroughly investigated. A bandaid won't do.

Paul

IMHO - No. It must be watched. Nobody is suggesting a band aid. Look at the picture and read the description. Squeaky clean bilge, nice shiny bolts, on again off again leaks. Yes it's a concern... watch. This isn't a medical issue. Waiting 3 months does no harm.

John