Keel Bolt / Stud Leaking

[Richard10002]

Well, I have had this response back from Bavaria confirming my questions about the 360 torque setting and the sealant/compound to use, this was the response. I have also attached a link to the Installation Manual below

https://drive.google.com/file/d/0B0TJ4TnMDd6BX0cyT0xHc1JWSG8/view?usp=sharing

"It is 360 Newton Meters (Nm). Yes the right sealant is Plexus MA 310 (incl. Metallprimer).
Attached you find a Manual to install a keel which I found in our data base.
If there is one bolt leaky only normally it is enough to loose the bolt, clean it, grind the laminate around the bolt and make it tight with Sikaflex, Epoxy or Plexus."

So, they seem to think if it is just one bolt leaking, and I assume because of the age of the boat (2007), I'm good to clean and reseal.

I'm sure some people aren't going to be happy about this!
Thoughts?.....

Resealing only around the top where the bolt enters the hole suggests that the incoming water is permanently in contact with the bolt... whether that is a satisfactory long term situation may be a moot point. In the narrowboat community, lots of boaters dont clean and paint the bottoms of their boats as they suggest that there needs to be both water and oxygen to cause corrosion, (and there is no doubt that there was more wear and rust at my waterline than at the side/bottom interface, after 4 years in the water).

I think I would want the whole thing sealed where the water is getting in at the bottom end of the bolthole, as well as at the top.

 

[Tranona]

So, they seem to think if it is just one bolt leaking, and I assume because of the age of the boat (2007), I'm good to clean and reseal.

I'm sure some people aren't going to be happy about this!
Thoughts?.....

Yes,but you need to stop the water getting between the keel and the hull as it is likely to cause corrosion of the stud at the interface. This will become clearer when you lift it out of the water. As has already been suggested there is likely to be a gap between the hull and the keel at that pointy after end which needs sealing as well as resealing under the nut.

 

[Harry Brown]

Yes, sorry, that's what a mean a proper clean and reseal, at the stud AND keel to hull interface. I will know more when I lift the boat to see if any gap is visible, I hope so! Got to be the first time in history someone is hoping for a gap! Lol

 

[vyv_cox]

Yes, sorry, that's what a mean a proper clean and reseal, at the stud AND keel to hull interface. I will know more when I lift the boat to see if any gap is visible, I hope so! Got to be the first time in history someone is hoping for a gap! Lol

One small point there - if you are going to fill from outside the boat needs to be hanging in the slings. Pointless doing it with the hull weight closing the gap, which will simply open again as soon as the weight comes onto the keel.

 

[Binman]

One small point there - if you are going to fill from outside the boat needs to be hanging in the slings. Pointless doing it with the hull weight closing the gap, which will simply open again as soon as the weight comes onto the keel.

It would help once you are looking for a gap while suspended, once found to slacken the stud off to increase the gap before filling.

 

[thinwater]

My first observation is the washer. There is absolutely no way on earth that washer is doing ANYTHING to spread the load. Might as well be tin foil. A backing plate or load distributing washer MUST be 50% of the bolt diameter to function (this is based on testing, not guess work). Thus, somebody didn't know what they were doing. I would remove the nut and look for fine cracking in the laminated under the nut. I would then replace it with a thick washer cut from plate.

 

[30boat]

My first observation is the washer. There is absolutely no way on earth that washer is doing ANYTHING to spread the load. Might as well be tin foil. A backing plate or load distributing washer MUST be 50% of the bolt diameter to function (this is based on testing, not guess work). Thus, somebody didn't know what they were doing. I would remove the nut and look for fine cracking in the laminated under the nut. I would then replace it with a thick washer cut from plate.

Thicker and much wider I would think.

 

[Javelin]

I think you need to take a step back.
If there's a leak the question is not how do you fix it but rather why did it happen.
As you can make a fix only for it to return.
Same issue with gell cracks at the base of stanchions.
Yes sure grind and fill the cracks and make good but unless you eliminate the flex that caused the cracks they will return.

So with your keel the plexus acts as an adhesive and a gasket.
If you have a leak the gasket has failed.
Salt water will then get in and corrode the studs/bolts.
The corrosion may be currently very minor or it may be more serious.
The fact is until you look you can't tell.

We have a similar problem with a Vic38 see
http://www.ybw.com/forums/showthread.php?426083-What-lessons-for-this-week/page9
Only in this case the fuel tanks, saloon bunks and half the galley had to be removed to get access to the bolts.
When we did we found just one stud which had corroded half way through where the nut was.
Given the owner wants to sail to Iceland and has just returned from Cape Horn plus a couple of Atlantic crossings the safe thing to do is to drop the keel and do a proper job.

In your case, depending on the sailing you do, I'd first find out how the studs are secured in the keel and whether you can withdraw it out.
If its a J bolt or galleried and cant be removed then a short term fix for a season or so of coastal sailing might be worth considering especially if its on a guide stud.
I can give you some options on various methods we've used in the past including on my own boat.
Re torquing should be done on a regular basis anyway so crack on with that now.

Dropping the keel can be a pain with keels bedded on sikaflex, Saba, plexus and the like but again I've got some techniques that will help you if and when you need that info.
Also factor in that if it was me you'll need to drop the rig before dropping the keel.

So in short my initial priorities would be,
1, Torque the nuts.
2, Lift out and inspect joint to see if its weeping.
3, Get the stud securing info.
4, Pull the stud out if poss and inspect.
5, If ok, drill, dry and pump arbokol or similar into the join and re torque.
6, If not or you're planning some off shore sailing drop the keel and get it done properly.

 

[doug748]

Very interesting post there Javelin.

Do you re-bed keels on Sikaflex or similar, or is there a good alternative that is less of a problem for future work?

 

[Javelin]

3m 5200 sealant by choice.
or Saba 750xl (i think)
Not a great fan of Sika anymore.

If you want to remove something at a later date and just want a great sealant then arbokol is best.

 

[Tranona]

While useful advice on fixing keels in general, if you read the whole thread you will see that the likely cause of the leak is well known with this boat. The construction is very simple, a straightforward stud screwed into the keel. The keel is very narrow at that point and the hull bottom aft is flexible. As many have suggested it should be possible to take out the sealant as far as the stud and reseal. Of course inspection may find greater damage, but this scenario is favourite based on previous experience with this design.

 

[Bobc]

My guess is that BOA is "Bavaria Owners Association" http://www.bavariaowners.co.uk/


I also would guess that Anne-Marie is the lady at Clipper Marine who deals with spares and servicing ... http://www.clippermarine.co.uk/contact

Correct on both counts. I'll try to be a little clearer in future.

 

[30boat]

While useful advice on fixing keels in general, if you read the whole thread you will see that the likely cause of the leak is well known with this boat. The construction is very simple, a straightforward stud screwed into the keel. The keel is very narrow at that point and the hull bottom aft is flexible. As many have suggested it should be possible to take out the sealant as far as the stud and reseal. Of course inspection may find greater damage, but this scenario is favourite based on previous experience with this design.

I definitely agree with the above.

 

[Harry Brown]

UPDATE:

Guys,

I was at the boat this weekend.
I need to eat some humble pie!!

I was 100% wrong, you guys were right. The keel bolt is not leaking, it is from elsewhere, (yet to be tracked down, fresh water leak slightly tainted with salt).
This is obviously good news but I am very sorry for wasting everyone’s time and appreciate all the help /advise that I was given.
When I first saw the water around the bolt, I panicked and talked myself into the worst, it really did look like it was coming from the bolt, further investigation proved otherwise.

I also apologize to every other Bavaria owner for muddying the already dirty waters regarding Bavaria keels!

The boat is sound, the keel is sound, and 39 Cruiser is still an amazing yacht!

Thanks again, I’m going to go finish my pie now!!

 

[jordanbasset]

Thanks for updating us

 

[Richard10002]

I initially thought it would be from elsewhere, but your video convinced me it was via the bolt.. The water seemed to come from nowhere, which could only mean from inside the bolt hole.

How did the video mislead us?

 

[Harry Brown]

I initially thought it would be from elsewhere, but your video convinced me it was via the bolt.. The water seemed to come from nowhere, which could only mean from inside the bolt hole.

How did the video mislead us?

If you slow the video right down you can see it coming from the water drain hole.
I accidentally found this because I was trying to grab the part number from the bilge pump and noticed what was happening when I watched frame by frame to get the number.
At full speed it looks like it is starting from the keel bolt!! Crazy when you see it. I couldn't believe it!

After this I isolated the bolt and sure enough, bone dry!!

 

[jordanbasset]

If you slow the video right down you can see it coming from the water drain hole.
I accidentally found this because I was trying to grab the part number from the bilge pump and noticed what was happening when I watched frame by frame to get the number.
At full speed it looks like it is starting from the keel bolt!! Crazy when you see it. I couldn't believe it!

After this i isolated the bolt and sure enough, bone dry!!

Agree slowing down the video is what I did, quite clear then

 

[Bobc]

UPDATE:

Guys,

I was at the boat this weekend.
I need to eat some humble pie!!

I was 100% wrong, you guys were right. The keel bolt is not leaking, it is from elsewhere, (yet to be tracked down, fresh water leak slightly tainted with salt).
This is obviously good news but I am very sorry for wasting everyone’s time and appreciate all the help /advise that I was given.
When I first saw the water around the bolt, I panicked and talked myself into the worst, it really did look like it was coming from the bolt, further investigation proved otherwise.

I also apologize to every other Bavaria owner for muddying the already dirty waters regarding Bavaria keels!

The boat is sound, the keel is sound, and 39 Cruiser is still an amazing yacht!

Thanks again, I’m going to go finish my pie now!!

That's good to know.

Check your stansions and deck fittings. The most likely cause of the leak is from silicone sealant that's broken down.

 

[[3889]]

I had no contribution to make on this matter but I'm sure no one thinks their time has been wasted. I've certainly benefited from this thread and I'm glad your problem is (hopefully) less than you feared.