Rust on keel

[richardh10]

Although I am sure I have seen this on here before, I cant find it with the search facility, so I will have to ask again.

I have noticed a few rust spots showing through the gelcoat and antifoul where the keel is on my boat. Presumably I sand back to bare metal, put on some primacon or similar and refill the hole. However one of the rust patches is where the (long) keel is joined to the hull, so if there is rust in that gap, how do I get to clean it out?

Thanks for any help

 

[richardbrennan]

I think the short answer is you cannot clean it out properly without dropping the keel, dealing with the rust and then applying several coats of your chosen primer or epoxy before putting the whole lot back together. Assuming you don't want to this, scrape out as much sealant as you can, apply your chose rust treatment, apply new sealant and then several coats of primer before the A/F.

 

[KellysEye]

If you go back to bare steel the first two coats should be zinc rich epoxy paint.

 

[vyv_cox]

It seems you are describing a gap between the hull and keel, and possibly other surface rust. Gaps are almost impossible to repair without dropping the keel off the boat and rebedding it. However, this is an expensive and lengthy process that is probably unnecessary unless water is entering the boat via the keel bolts. You will find it very difficult to prime and fill the gap with the weight of the boat on the keel and it will open up as soon as the keel hangs from the boat.

It's your decision whether the full job is needed but otherwise don't spend too much effort on it and monitor the condition.

 

[PhillM]

I'm no expert but I thought this was one of the uses of red lead putty?

Sand what you can get to, prime, fill the void with the putty, leave it for a week to skin, prime then AF.

 

[Halo]

I had the same problem for 25 years on my previous boat. I thought it would be a mistake to dig out the sealant and disturb an essentially sound joint so each year I pulled off any obviously loose sealant, painted the rusty bits I could see with Kurust , primed the blue bits , then applied sealant to make the surface suit the hull/keel surfaces, and antifouled. This became a routine and small part of the annual antifouling procedure. It never get worse (or any better).
As rust takes more space than the iron or steel it comes from I thought as small ammount of rust would tighten rather than loosen the joint.
Personally I would not remove or drop the keep for a small amount of rust - it is virtually impossible to stop a recurrance any way so I would live with it - unless there is any sign of water ingress to the boat