Iron Keel Corrosion

[marti972]

Please help me identify what the corrosion is, on the top/leading edge of the keel. I think it's the spider cracks, that are concerning. But, any other details may be useful.


,A little more detail is that, the boat has been on the hard for the virus and now is getting ready to be put back into use. The surveyor started the discussion when he indicated,


"The keel has minor separation at the hull to ballast joint and a 1/32" x 28" drop of the trailing edge and 1/32" x 8" +/- fwd of keel. Repair prior to lunching. *C.10 The keel has minor separation at the hull to ballast joint and a 1/32" x 7" drop of the trailing edge of keel."


The response by the yard was to grind and have a look, then seeing nothing unusual filled it with the epoxy, seen it white.


Nothing was found when looking at the keel nuts, they are 2 1/4" and stainless. They look very nice and no rust. I am organizing to put a little torque on them and see if any are loose, but I've had to find some 1" drive tools. Also, the fiberglass around them all looks fine.

[capt jgw]

That happens with a lot if not all bolt on keels eventually. Crevice corrosion can occur in the interface of the iron and glass or up in the glass itself. The bolts can be rusted to near nothing in the joint and still look fine up in the bilge where you can see them, so appearance up there doesn't really tell you anything. With a lead keel the only way to know is to drop the keel. The bolts are usually "J" bolts cast into the lead so you can't get them out. Iron is different, usually the bolts are just threaded into the iron and can be removed relatively easily, and easily replaced if you can find new bolts or threaded rod the same size. It can even be done in the water one bolt at a time. I would try that before going back into the water.

[marti972]

Your reply was very interesting! I wonder if I should try, but wait. It is "all thread" with a nut on it. So, how would I get the "all thread" out of the iron?

[capt jgw]

If there's room above the nut for another nut, screw one on tight and turn the bolt out with the lower nut. When I did mine I used a bolt extractor. Kind of like an "easy out" but screws down on the outside of the bolt. That damages the threads though so the bolts would have to be replaced regardless of their condition. I had already decided they all needed to go so that was not an issue.

[capt jgw]

Using the jam nut method, if you can find a nut with a smaller outside diameter or grind a standard one down smaller you can turn the lower nut with a deep socket without touching the upper one. The rod should come right out.

[marti972]

Okay, that sounds doable and I'm really liking the idea. But, how much force are you expecting it to come out with? I'm just asking, because I want to know when I'm getting into "don't even try it" territory.


A bit of history. The boatyard is small and the guy in charge says, "we are not going to remove a keel here. First we don't have any way to hold the boat up and second you are not going to tie the travel lift up for a month!" So the concept of messing up, is a challenge.

[capt jgw]

No way of knowing how much force would be needed. It's a matter of how tight they are, how long they've been in there and did they use thread locker. I'd get a 24" breaker bar and apply even pressure increasing till it comes free. And yes the boat can be blocked up without the keel, they did mine no problem. Sat that way all winter.