Rusty hull to keel joint


New member
8 Mar 2011
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I want to remove the rust around the keel root of a Hunter Duette. The picture illustrates the problem. The consensus in PBO and this forum seems to be that it's likely to be a cosmetic issue rather than something serious. However, I want to try to fix it, and will give the keels a shuggle when the boat is in the slings to make sure that there is not a more serious problem.

There is some useful guidance in PBO April 2011 on fixing the rust, but, being very new to this sort of thing, some more detailed advice would be welcome:-

1) PBO advises removing the paint first. Presumably this refers to the antifoul (Cruiser UNO in my case). Is there an obvious best way to do this for the hull/keel joint? A triangular scraper perhaps?

2) Then, I guess, wirebrush to remove the rust. When is the best time to apply the rust remover: before, during, after, or all three?

3) PBO then suggests priming with rust remover. This seems strange: what priming action does the rust remover have?

4) PBO then suggests an epoxy primer. Any suggestions as to brand?

5) Then Sikaflex to fill the gap between hull and keel. It looks like Sikaflex 291 is the one to go for here. Any opinions?



Well-known member
16 May 2001
France, sailing Aegean Sea.
1. A scraper is as good as anything. You need to remove as much as possible this way.
2. A wire brush is by far the worst way to remove rust from a keel. Rust is driven into the surface, where it prevents good adhesion of paint layers. An angle grinder is a far better way to get down to bright metal.
3.I have no faith in rust removers and wouldn't use it
4. Any epoxy should be good. I use West general purpose epoxy but there are specialist primers. Your problem is that it is better not to apply it over existing paint, so it will be difficult to waterproof the joint between the two.
5. Complete waste of time. When the hull is resting on the keel the gap will be relatively closed. As soon as you are launched the gap will open. If you see rust that is coming from the keel inside the bilge you would be best off rebedding it. If not you could fill the gap when the boat is hanging in the slings.


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26 Jul 2004
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After nesting this thread into one to help a forumite I thought I had better update it.

Ground off areas with a disc grinder.
Applied vactan (too about 3 hrs to dry)
Applied two coats of International VC2 epoxy tar. (can be worked above 5 deg C , worried it would not 'go off' but it did'
Antifouled with 3 coats of Blakes Tiger Extra

Time will tell.

My only problem I think is that I have bonded the blocking up wood to the keels with epoxy.
I will have to knock it off and apply antifoul just before she goes in.


Well-known member
9 Apr 2005
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You may improve matters slightly by using jakes procedure but you will find that the rust re-appears after a while. The reason is that you can't remove all the rust on the top face of the keel without removing it and applying a robust treatment system over the entire area before re-seating.
Good luck but I fear you will be doing the same job in a couple of years.