Keel bolts in cast iron keels

[Ellida of Laira]

I have recently purchased a 1999 Saltram 40. It has a cast iron keel. I don't know when the keelbolts have been looked at or replaced. The mastic in the hull to keel joint is degraded. The yacht has been sitting in a marina for 4 years and the anodes have not been replaced.

I would appreciate advice about
1. what is the best way of removing the keel bolts to examine them, I imagine that the mild steel bolts are rusted into the keel by now. does anyone have any advice?
2. what is the best way to protect the new bolts from corrosion? would a Galvanic Isolator or similar device protect the bolts?

no doubt this problem has been ventilated before, could someone point me to helpful threads
Thank you
Russ

[barnakiel]

If you see the bolts (=heads), you may have bolt pockets. This is especially so if you see paired bolts in the bilge. If you have pockets, this is all simple : empty the pocket, pull up the bolt, examine. ALSO examine the pocket.


With cast iron keel, imho, the keel is sacrificial = the bolts may be looking sweet, but the pocket area may be corroded (sign = black powder).


If, however, you can see nuts in the bilge, then the bolts may be "cast in". Then there is no way to inspect - unless you lift the hull and drop the ballast (leave it as is, the boat to be stored now next to it.


At times, when the dry is not hard, people will dig a hole under the keel to drop it. I do not recommend this as I witnessed and it was super messy project.


For cast in bolts, which are common in lead, but not absent in cast iron ballast, there is just this much one can inspect - as most of a bolt is hidden anyways. And gods only know what happens down there.


The light in the tunnel is that Sagas were very very well built, and if you replace or repair the iron to grp interface then you are extremely unlikely to have any keel bolts problems. Unless the boat was grounded in a very very bad accident. Normal grounding does no harm on Sagas - as they were built to take this in her stride.


Look at the ballast slab well from the outside. If there are pockets, they are filled with epoxy putty. Epoxy contracts over time and you can see the pockets as a series of flat 'hollows' - some one inch below the grp/slab seam.


Send pictures. But take things easy - you have 99% chance of having a perfrct keel and bolts. It is a Saga, not a Bene.


Not sure if the anode on the ballast is to protect the bolts (???). On our boat there is no anode on the ballast. Nor is there any rust on the ballast, nor on the bolts (SS).



b. (cast iron keel, boat built 1980, original keel bolts)

[barnakiel]

ps Make sure it is not lead - I have seen at least one Saga 40 that had a lead ballast.


b.

[Ellida of Laira]

Thank you very much for your thoughtful and helpful replies

[SailingHarmonie]

If the sealant between the keel and the hull has degraded, you NEED to drop the keel and repair it. This would apply no matter what kind of keel you have. Even it you could replace the keel bolts in situ, the problem is still the failed seal.

Corrosion of an iron keel is not subtle. Iron oxide is something on the order of 40 times larger in volume than the original metal. It will drip, ooze, bulge, force it self out of the tiniest cracks.