Rusted Keel (Cast Iron) on Beneteau

[RigelKent]

Was wondering if any Beneteau owners had rust starting on their keel, and what steps are recommended to maintain the keel in good nick.

Mine has some rust started near where the keel meets the hull, at the leading and trailing edge. Keel bolts (appear) OK from the outside but obviously that's no indication of what is going on inside.

What type of work, tools, treatments would anyone care to recommend for stopping the rust? What kinds of preparations, caveats, necessary for dropping the keel whilst doing a haul-out for this maintenance? Any helpful experience or opinions appreciated.

[Heikki]

I am not a Beneteau owner, however, as an owner of a steel boat, I know something about rust. If you need just a general advice on how to get rid of rust on a keel, I'll be happy to help.

[RigelKent]

Hi Heikki, I've done rust removal on cars, even old steam engine trains. Helpful if someone's been through similar maintenance - wondering about what works best to remove the rust - naval jelly? Best tools to use in a boat yard? How to support the boat when the keel is removed? What to use to fill any depressions resulting from removed rust? What to paint on after removing the rust? Any issues or steps that might not seem obvious (to me at least), Thanks!

[MacG]

Originally Posted by RigelKent

Hi Heikki, I've done rust removal on cars, even old steam engine trains. Helpful if someone's been through similar maintenance - wondering about what works best to remove the rust - naval jelly? Best tools to use in a boat yard? How to support the boat when the keel is removed? What to use to fill any depressions resulting from removed rust? What to paint on after removing the rust? Any issues or steps that might not seem obvious (to me at least), Thanks!

Sandblasting. As simple comme bonjour.
Then epoxy treat the keel.
A whole dismantling of the keel requires some good preparation. You might (or not) find rusty bolts.
My boat is steel en has an welded keelbox. Filled with lead-ballast and topped of with oil.

[fstbttms]

Rust blooms on iron-ballasted keels are extremely common and I see it every day. My experience is that nothing you do will cure it completely.

[barnakiel]

Google for iron keel repair benneteau and there is somewhere out there a very nice essay by people who did the full job.

A localised rusting can be simply cleaned and re-primed with epoxy primer (thick).

b.

[RigelKent]

Thanks for the tips and search params. This came up - answers my questions about fairing compounds, barriers coats etc, thanks!
Beneteau First 235 - Iron Keel Restoration
Also some helpful discussion on
Iron Keel Rust - SailNet Community

Because the rust is near the hull, I'd need to drop the keel to do the work so will enquire about boat yard facilities to support the boat during the keel sandblasting, sealing, fairing, etc.

[bene505]

Originally Posted by RigelKent

...Because the rust is near the hull, I'd need. to drop the keel to do the work so will enquire about boat yard facilities to support the boat during the keel sandblasting, sealing, fairing, etc.

I disagree. I couple months ago I addressed the rust that was up where the keel meets the hull. I used one of those vibrating "cutter" type tools.

Google "Bene505 fixing keel rust grind" for my trials and tribulations while learning a few years ago.

Regards,
Brad

[RigelKent]

Originally Posted by bene505

Google "Bene505 fixing keel rust grind" for my trials and tribulations while learning a few years ago.

Reminds me a bit of that other story, 'Journey to the Center of the Earth'

Can you give any specifics about the vibrating cutter tool? I've seen something like a vibrating putty knife for removing barnacles - similar to that?

When lifted a few months ago, the surveyor had marked the rust and we watched water drip from between the hull and keel at those points but after a half hour or so the water stopped.

So there would be water entry (an assume rust also) between the keel and the hull. No rust on the keel bolt heads visible inside the cabin though, no interior leaking and the bolts seem quite solid as far as I can see.

Other than the leading and trailing edges at top of the keel, the rest of the keel seems ok with no rust showing. Has some type of barrier coat on already, probably epoxy.

[tomtom]

I'd consider giving it a good sanding/grinding and coating with POR-15. I found out about it years ago when I was dealing with some rust on my Land Cruiser. I coated my keel bolts with it about 18 months ago and am happy with the results. I am thinking about doing my keel the next time I haul out.

Check it out here...

What is Por-15? - POR-15 Inc.

I have nothing to do with these guys, just happy with their product.

[Sam Plan B]

I had that problem with my Columbia 41. It has a cast iron keel that weeps rust when hauled for a new bottom job. Cast iron rusts much slower than steel so with the weight of the keel it is not a big problem for a long time. I chipped out the rust blooms and blew out with compressed air. Let it dry and filled the cavity with thickened epoxy. Faired and painted. I also replaced my keel bolts with 3/4" stainless threaded rod with stainless nuts and washers. Same thread and diameter rod as the original. No problems since.

[Rocketman]

I had rust on my keel also, but it was mostly comming from the leading edge and the bottom of the cast iron keel. It originally had a plastic like coating around the cast iron keel and small cracks in the plastic allowed water to seep in causing the cast iron to rust, which showed up as rusty blooms on the outside of the plastic coating. I decided to grid off part of the plastic to see how bad the rust was, and found that below the plastic it was pretty much holding water between it and the cast iron. So I removed all the plastic and ground most of the rust off. If I could have used a sand blaster at the boat yard, I would have sand blasted it also. After getting as much of the rust off as possible I used a metal prep, that turned the rust black, then a metal boat paint, and put about 10 coats of that on which was silver in color, then epoxy paint, then finally bottom paint. I did not re-apply the plastic coating, as I knew I was not able to remove all of the rust and it would have simply been able to rust inside the plastic. I did this 2 years ago, and when I dive the boat monthly and removed it for new bottom paint this year, there was no significent increase in new rust. I would like to hear from others what there thoughts are on this repair. It seem to be working ok for now, but I am concerned about the longevity of the keel. I have concidered taking the boat out next year to a yard that allows sand blasting and removing all rust then re-applying a plastic coating as it had orriginally but I don't know if it would be as good a what I have now. The problem I see with the fully incapsolated cast iron keel is it can be rusting away below the plastic and little can be done to stop it.

[Amnesia II]

Originally Posted by RigelKent

Reminds me a bit of that other story, 'Journey to the Center of the Earth'

Can you give any specifics about the vibrating cutter tool? I've seen something like a vibrating putty knife for removing barnacles - similar to that?

When lifted a few months ago, the surveyor had marked the rust and we watched water drip from between the hull and keel at those points but after a half hour or so the water stopped.

So there would be water entry (an assume rust also) between the keel and the hull. No rust on the keel bolt heads visible inside the cabin though, no interior leaking and the bolts seem quite solid as far as I can see.

Other than the leading and trailing edges at top of the keel, the rest of the keel seems ok with no rust showing. Has some type of barrier coat on already, probably epoxy.

You seem to have a more pressing problem if you..." watched water drip from between the hull & keel for 1/2 hr. "

I would be more concerned there as that sealed joint is important.... to protect the keel bolts in my opinion!

My expertience working on Beneteau keels showed they were made of cast steel not cast iron. I welded up alot of deep pitting on Beneteau keels.

Catalina are one of a few production builders who continue to offer lead keels for various positive reasons.

[GordMay]

Greetings and welcome aboard the CF, tomtom.

I can also recommend Por-15.
➥ http://www.por15.com/Data%20Sheets/n...directions.pdf

[familycruisers]

If its truly cast iron it will take forever for the keel itself to rust. My boat has them and the couple of blooms that had popped up behind the barrier coat the PO used were small and insignificant imo. Especially since my boat is 42 years old.
I wouldn't like leaking at the keel/hull joint though.