How to maintain laminated keel bolts - Jeanneau Sun Shine 36

[Sonni]

The keel bolts of our Jeanneau Sun Shine 36, year of manufacture 1985, are laminated to the hull originally. Some look fine, some show traces of rust on the laminate.
Does anyone has experience with the maintainance and/or replacement of the bolts? We are not sure what´s the best way to remove the laminate to see the bolts.
I attached two pictures, showing the situation in the bilge. One with rust, one without (sorry, the bilge needs to be cleaned and painted...)

[tkeithlu]

Welcome to the forum, Sonni.

Ouch. You have rust under layers of fiberglass. The items rusting, your keel bolts and the nuts on top of them, are critical to the structure of your boat. So, you've got to find out how serious the problem is.

Fiberglass over the top of the bolts is not making much of a contribution to the strength of the attechment of your keel. I suggest that you cut it off with a wood chisel - it will cut the fiberglass without damaging the bolts or nuts. Using a grinder could cut right through the bolts and multiply your problem, so don't do that.

Once you've cleared to the bottom of the nuts, you should be able to see the extent of the damage. Now here's the scary part - the rust could be superficial, or the strength of your keel bolts could be compromised. If there is not enough steel holding your keel to your hull, the keel has to come off and have new bolts attached. That's major surgery.

Let's hope that what you find is rust only to the level of the nuts, such that you have to replace them one at a time. The next task is then making sure that seawater does not get to the new nuts and repeat the problem.

Best of luck with it.

[Gary Mc]

Yep, tkeithlu has it right a chisel and hammer. Looks like they just poured some resin over the nut and bolts at the factory. Not a good practice but it would have kept out most of the salt water hopefully?


Open it up and hope for the best. Even if they are in good shape it will be time to torque the keel bolts since that has obviously not been done.


On my boat when I got it 20 years old, the nuts were CS and the bolts SS. The nuts were just about rusted away, I was able to cut them off with a chisel, clean up the SS bolt threads and put new SS nuts on. No issues since.


Good Luck

[Searles]

I would dought that mess is from the factory build ,probably an attempt to control leaky keel bolts,a sharp wood chisel is good for cutting the glass mess away ,once opened the rest may peel off ,do not attempt this job in the water, this is a job to be attended to on the hard,⛵️⚓️

[GordMay]

Greetings and welcome aboard the CF, Sonni.

[Sonni]

Thank you so much for your replies.

Today I took a chisel an a hammer to the boat yard and it was not too difficult to remove the laminate. I did it with the two bolts where the laminate was looking worst.

Between the laminate and the bolts there was a very hard and very white material. The bolts and nuts look much better than expected, but the plates underneath are corroded. I think I have to replace them... what do you mean?

The laminate was wet, but that was no surprise because we had some saltwater in the bilge. But I am not sure if this really caused the problem, or maybe the wetness causing the corrosion is coming from the other side....

[Cheechako]

Yeah, that's chopper gun laminate over the bolts. Ugh. Oh well it comes off readily anyway...
It will be interesting to see if those nuts will come loose. It all appears to just be steel, maybe that's why they choppergunned over it.

Next question is:
Remove the keel, rebed and put in new fasteners?
Possible to just replace the studs etc, with no keel drop needed?
Do the studs even come out or are they J hooks?
Maybe Jeanneau can help you know what's there....

[donradcliffe]

Try a small magnet on the plates, nuts, and bolts.

[Sonni]

Originally Posted by donradcliffe

Try a small magnet on the plates, nuts, and bolts.

Thanks a lot. I will try that in the next step!

[Sonni]

Originally Posted by Cheechako

Yeah, that's chopper gun laminate over the bolts. Ugh. Oh well it comes off readily anyway...
It will be interesting to see if those nuts will come loose. It all appears to just be steel, maybe that's why they choppergunned over it.

Next question is:
Remove the keel, rebed and put in new fasteners?
Possible to just replace the studs etc, with no keel drop needed?
Do the studs even come out or are they J hooks?
Maybe Jeanneau can help you know what's there....

I did not had any WD 40 on board. Will take that with me for the next time an hopefully be able to get the nuts loose...

[Manateeman]

Lot of good advice above. If the seal between the hull and keel is broken, the strength of the bolts is questionable.
I agree with a prior post that the glass covering the nuts and plates might have been an effort to stop leaks. If this was the case, pulling the bolts would be correct. You don’t want to sail with thin bolts. Dropping the keel in the yard is less costly than having it become loose and breaking the hull. It doesn’t need to fall off to cause a lot of damage and a much more costly repair.
Check the record of the yard in doing this repair. Please let the forum members know how things went as this helps others.
Don’t be discouraged . Do this repair correctly and just sail on.
Happy trails to you.
Captain Mark and the manatee crew.

[Uncle Bob]

This is an example of lipstick on a pig. It is not laminated keel bolts, but an attempt to repair or hide a problem that should have been repaired instead of covering up. Fix it correctly and all will be well.

[Sonni]

Originally Posted by Uncle Bob

This is an example of lipstick on a pig. It is not laminated keel bolts, but an attempt to repair or hide a problem that should have been repaired instead of covering up. Fix it correctly and all will be well.

I know an owner of the same boat, built in the same year. The laminate on the keel bolts looks exactly the same. For that reason I thought laminating the bolts was something they did when building the boat in 1985...

[Laureat]

Looks like your keel bolts are not like mine I have a Beneteau Oceanis 430 1987, yours looks like a rod with a metal plate than a nut on top mine are a 3 inches steel bolts grade 8 with a washer. We are now replacing the 7 bolts, out of 10 started a week ago, replacing one bolt a day, it is a job. My husband uses a hammer drill with socket 28mm, but prior to that he uses liquid wrench for a day or two before attempting to remove the bolt, some of them he had to use a 22mm bolt extractor with his hammer drill, after cleaning the rust on the head with a dremel tool. So far all of the 7 bolts are not rusted, very good condition, just the head rusted very bad, because they have a metal sleeve in the iron keel, pass the hull of fiberglass of around 1 inch 1/2 deeper. The worst part is three of the bolts are situated under the floor, maybe he will have to remove a portion of the benches, table etc to reach those final bolts hopefully this week. Good Luck you need to change them for sure

[SV Zig Zag]

That is factory on the SunShine 36 and SunRise 34 of that era.
Never had a problem with my 34.