Keel Bolts Question

[afterwork]

I put a deposit down on a 2009 Jeanneau 50DS and one of the comments from the survey is that the keel bolts need to be inspected as they appeared rusty. Specifically, the aft most bolt which was severely corroded. Since then, I cleaned off all the rust and backed off the nut to inspect it. It appears to be only surface corrosion and the bolt is fine (see photos attached).

During my inspection I found that the forward most bolts are completely covered in silicone (see attached photo). Does anyone know why they would do that to these bolts and is there an easy way to take all that silicone off to inspect it? My main concern is oxygen depletion on stainless steel so I would prefer to remove the silicone but I would still want to know what is the purpose of this and if anyone has seen it before.

[wyb2]

That doesn’t look like stainless. In that case, the coated bolts/plates aren’t quite the same hide-the-problem risk, any significant rust will happily split open the silicone.

I’m sure someone familiar with the model will be able provide more specific advice.

[afterwork]

Originally Posted by wyb2

That doesn’t look like stainless. In that case, the coated bolts/plates aren’t quite the same hide-the-problem risk, any significant rust will happily split open the silicone.

I’m sure someone familiar with the model will be able provide more specific advice.

Thanks, you are right it doesn’t look like stainless but I was wondering what else it could be for this application? I thought standard use here was stainless.

[wyb2]

Originally Posted by afterwork

Thanks, you are right it doesn’t look like stainless but I was wondering what else it could be for this application? I thought standard use here was stainless.

I think carbon steel studs/bolts are are sometimes (often?) used in iron keels. Unlike lead, iron is hard/strong enough to be tapped, and a threaded in bolt is replaceable. Between iron and SS, iron is the anode, so a SS bolt could encourage the iron threads to corrode away. I think the idea is replacing a rusty bolt is a lot easier than redrilling and retapping the keel.

Honestly I’m just regurgitating what I’ve read over the years though. My big boat had a lead keel. I just noticed a few hours had gone by with no answer. Someone with firsthand knowledge will find this sooner or later, listen to them.

[psk125]

Beneteau routinely uses steel bolts in their cast iron keels. As wyb2 says, the keelbolts get tapped into the keel, making their replacement quite simple when necessary. Some people apparently replace them one at a time without even hauling out.

[neilpride]

A few years ago I lowered the keel of a B50 Oceanis, it is the same concept, I am not sure if it is silicone, I have never seen it like this in Jeaneau or Beneteau, it may be the same Gelcoat used when they painted the inside of the bilges, it is not stainless steel, it is carbon steel.

What I did because the counter grid mold was detached from the hull, was to lower the keel and do a horrendous job inside to re-laminate the bilge bays to the hull, a job that I do not recommend to anyone because of how dirty and expensive it is.

If I can give you an opinion, if you can loosen as seen in one of these photos the top nut of the affected bolt and change them,it would be nice.

If they are well after a good cleaning, cover them with epoxy primer, but they have to be with 0 rust, otherwise leave them as they are , a dry bilge in these boats is essential to last for many years.