Rusty Keel Bolts

[MattS]

I was replacing the bilge covers in the galley cupboard tonight, and noticed some rust around the keel bolts. The boat is a bilge keel.

The thing that concerned me is that on touching one of them, it was clear that the plate was very rusted under the black protective paint, and it easily started to come apart without much pressure.

I then tested the corners of a nearby plate, and one on the port side, and both also appear to have rusted plates that I could probably pull chunks off without much effort.

My survey last year rated the keel bolts as being fine, but this seems to suggest to me there is quite advanced rusting..

With no real frame of reference, my first concern is whether this is even safe to sail, or if I’ve got a very advanced safety issue hidden by the black paint that’s been applied to them…

Any thoughts would be most appreciated - no idea how cautious or concerned to be about this.

 

[Rappey]

From being surveyed as fine to the current condition in a year seems a little suspicious.. Is or has salt water been in your bilges since youve owned the boat?
I would suggest removing all the black paint to get a proper look at the nuts and plates.
Do you have rust stains or water coming from the outside keel to hull joint?

 

[MattS]

The bilges have been bone dry since I bought her last year, apart from fresh water from a companionway leak.

And these are bilge keel bolts, so quite a way off to the side - so pretty sure no chance they’ve been sitting in salt water.

No evidence of any water getting in either.

I know the keel joints need re-sealing and have work planned in September to do that - but I’m now wondering whether it’s even safe to sail her the 50nm to the boat yard… no frame of reference, but they seem pretty disintegrated!

 

[Rappey]

They look in a very poor state tbh, but since im no expert and cant possibly see what state the bolts are in where they pass through the grp then its a big guessing game..
If the worst were to happen you just dont know if they would start leaking first before failure or if the keel really could drop off.. Its also possible they could last many years to come..
Its been suggested that every so many years a keel should be lowered from its mountings to inspect the bolts, but no one does this and just assumes all is well.

 

[RichardS]

Until you get the paint off with a wire brush or a drill with a wire brush bit, it's going to difficult to properly assess their condition.

Richard

 

[Richard10002]

The keel bolts on my moody 44 looked like that, (no paint), so I had them pulled an replaced. Turned out to be surface rust, the nuts and bolts were fine otherwise. Cleaned them up and, whilst there was a bit less metal on the tops of the nuts and bolts, I had a spare set.

The trouble is, once you have worried yourself, it’s hard to become not worried without withdrawing all, or a few, to see how they look.

 

[neilf39]

When did you last see them? I can't see a survey saying they were fine if the rust was that visible and flaky. If they have been dry all the time it is hard to see how they could degenerate after the survey to that. Did you expose the rust that is now showing in the photos or was it like that when you looked? If you exposed it then it looks like that black paint was painted over the rust to make it all look ok. so could have been like that for some time. If it has genuinely been dry in the bilges around the bolts all the time then it may have been like that for a while. You are probably ok until you come out of the water but maybe don't do the trip in boisterous conditions. You could just pull one bolt where it looks worst and see what the overall state is. Certainly worth getting rid of the black 'paint' to get a better view. If you are uncertain it may be worth getting a marine engineer or surveyor to take a look/pull a bolt for peace of mind. The previous owner of my boat did that at one time as it was in the paperwork when I bought her.

 

[penfold]

My survey last year rated the keel bolts as being fine, but this seems to suggest to me there is quite advanced rusting..

Quite unusual; most surveyors have an obsessive/pathological interest in keel bolts and would strongly recommend, nay demand, that these be inspected and possibly replaced.

I'd be inclined to remove and replace all the nuts and washers/ load spreading plates; one at a time obviously. The black paint(which is offering no protection at all) and the rust needs chipped off- a welder's hammer would be easiest but access may dictate what you use. What is revealed would then tell you whether it needs doing now or can be postponed until the winter haul out.

 

[Tranona]

Par for the course with a Moody. Mild steel studs plates and nuts in a damp atmosphere over 30 years equals rust. As in post#6 almost certainly the studs are fine and there is no cause for concern about the integrity of the hull/keel joint. If you have severe rust stains down the keel in way of the studs do you need to worry about leaks from outside. Looks like somebody in the past has cleaned them up and painted them. Rust is like blood - a little bit goes a long way and looks far worse than it is. Next time you have it out of the water it is worth cleaning off all the muck and assessing whether the washer plates have corroded too far. Take the nuts off and replace the plates and maybe the nuts and paint to reduce the chances of further rust.

Pretty sure you will find something on the MOA site about this common issue.

 

[MattS]

Thanks for all the replies

She's coming out of the water next week for 2 weeks - so I can take a look for any obvious issues from the outside then.

And then she's booked to have the keels restored in Suffolk in at the end of August, so to be honest that's the ideal opportunity to really take a proper look at them.

It feels like I probably don't need to be cancelling my trip away this weekend...

The keel bolts on my moody 44 looked like that, (no paint), so I had them pulled an replaced. Turned out to be surface rust, the nuts and bolts were fine otherwise. Cleaned them up and, whilst there was a bit less metal on the tops of the nuts and bolts, I had a spare set.

The trouble is, once you have worried yourself, it’s hard to become not worried without withdrawing all, or a few, to see how they look.

Par for the course with a Moody. Mild steel studs plates and nuts in a damp atmosphere over 30 years equals rust. As in post#6 almost certainly the studs are fine and there is no cause for concern about the integrity of the hull/keel joint. If you have severe rust stains down the keel in way of the studs do you need to worry about leaks from outside. Looks like somebody in the past has cleaned them up and painted them. Rust is like blood - a little bit goes a long way and looks far worse than it is. Next time you have it out of the water it is worth cleaning off all the muck and assessing whether the washer plates have corroded too far. Take the nuts off and replace the plates and maybe the nuts and paint to reduce the chances of further rust.

Pretty sure you will find something on the MOA site about this common issue.

Thanks both - sounds like this isn't unusual for a Moody which is reassuring. I have found some useful previous threads on the MOA, but couldn't find any previous pictures that directly compared to this condition.

You're absolutely right @Richard10002 - my issue is that now I've seen it, I'm worried about how close my keels are to falling off

When did you last see them? I can't see a survey saying they were fine if the rust was that visible and flaky. If they have been dry all the time it is hard to see how they could degenerate after the survey to that. Did you expose the rust that is now showing in the photos or was it like that when you looked?

On Keel Bolts, the survey said: "The accessible mild steel studs, nuts and backing plates were found tight and in serviceable condition having been over-coated with a black protective coating."

To be fair, I haven't noticed any real difference in the appearance of the bolts since I got her - most of the rust visible in the photos was revealed by me pulling the chunks of rust (And paint) away. So it certainly didn't look that bad until I started poking around - there were just some bits poking through that caught my eye.

I definitely can't see any evidence of dribbling, or rust stains running down from the bolts (but can't check all as some as below water tank).

 

[penfold]

Scantling sizes on keels(I don't suppose Moodys are any different) tend to be on the massive side of things; chip the rust away, take some pics and post them up; it's entirely possible they're fine and it's just cosmetic, rust takes up an order of magnitude more room than the steel from which it sprang so it looks dramatic even when it isn't.

 

[Graham376]

Thanks both - sounds like this isn't unusual for a Moody which is reassuring. I have found some useful previous threads on the MOA, but couldn't find any previous pictures that directly compared to this condition.

I wouldn't worry too much, the nuts and plates on our 346 twin keeler looked much the same, a minor Moody problem. When you've hammered the rust off the nuts (and used a socket a couple of sizes down) the studs will come out with the nuts and almost guaranteed the studs will be fine. I took the studs out in pairs when on the hard, replaced with new 24mm ones cut from screwed rod and cut plates from IIRC 4mm x about 75mm flat. Unless there's visible movement or water squirting out of the hull/keel joint when lowering to ground, no need to drop the keels.

 

[jwilson]

They look bad but a little rust goes a very long way: it expands and the flakes are far fatter than the original steel. Clean them up very thoroughly, all black off, all loose rust off, scrape and clean back to steel. When I did it I used a dremel to clean up the difficults bits and then finished the cleaning with phosphoric acid. Then decide. In my case despite originally looking a bit dodgy with rust they came back to near perfect, and I then gave them four coats of high-zinc paint. Three years on tiny rust spots through the paint in a couple of places. I'll repeat the process when it gets worse. These were fin keel bolts that inevitably get some salt water on them every time you clean the log impeller.

 

[MattS]

As an update to this - I followed the advice and started to clean up the worst looking bolt with a chipping hammer and Dremel with wire brush attachment.. after probably no more than 10 minutes of cleaning up, I hit what felt like pretty solid metal and I am already more reassured!

Before


After

 

[Graham376]

Glad you're happier! If that were my boat, I would carry on sailing as usual this summer and then change studs, nuts and plates at next winter's haul out.

 

[MattS]

Glad you're happier! If that were my boat, I would carry on sailing as usual this summer and then change studs, nuts and plates at next winter's haul out.

Still in need of a change in your view then?

I’m definitely happy to carry on sailing for the season - but as it happens she’s out of the water having keels restored in September anyway, so that may well be the time to just bite the bullet…

 

[Graham376]

Still in need of a change in your view then?

In your original post you mentioned the plates were badly rusted and coming apart so yes, I would change them. Not a hard DIY job and materials don't cost much.

 

[Richard10002]

In your original post you mentioned the plates were badly rusted and coming apart so yes, I would change them. Not a hard DIY job and materials don't cost much.

But now that he has got rid of the rust, he has a proper looking nut and plate which appear to have lots of life left in them.

I experienced similar, but I had had a survey done which commented on my keel bolts and, as I was planning to sell, it made sense to replace, thus avoiding the need to explain away the issues on the survey.

Had I not been planning to sell, I would have cleaned up and refitted the keelbolts, which might still be sitting in the rear locker on the boat, 12 years later

 

[ghostlymoron]

For peace of mind I'd remove the nuts and washers and replace with new. Perhaps draw a couple of bolts and check for necking. I don't paint the nuts as it's more likely to trap water under it.

 

[Rappey]

I'm really surprised just how much healthier the nut looks once it's cleaned up.