I am renovating a sail yacht from 1908 and it has an iron ballast keel. The keel is around 1.5tons and has 7 iron bolts size M26. The yacht is built with steam bent oak frames and fastened with copper rivets. The keel bolts are very rusted and I was going to start by removing the keel and getting it sand blasted and coated with primer and then some suitable paint.
Now, I need to choose the mateiral for the bolts. The most compatible bolts are of course galvanised iron bolts. But, I read in some books that it is best to replace them with stainless steel bolts. But, i also read that stainless steel should not be used below waterline, especially if the keel is oak.
So, what is a good solution!?!
1. replace the keel bolts with galvanised iron bolts
2. replace the keel bolts with stainless steel bolts.
3. redesign & cast a keel in lead and then use stainless steel bolts.
I see that this is an exercise in compromises.
So, if I say that I want to make the best possbile choise, in terms of longevity of the keel bolts and the boat. what would be a good solution.
The cost of this choice is small compared to the entire project. I would like to rebuilt the boat like it was before with copper rivets for fastening the planking to the steamed oak frames.
What would be a good way to go?
Please let me know if I missed any details. Thanks for any tips.