Pitting in stainless shaft

[bert]

Confirmation that the deep sea seals are connected to the cooling system on the engines, so as long as the engines run then the water in the shaft tubes should be oxygenated.

I'm thinking of pickling paste and passivating the shafts and putting them back in. I'd plan to have her lifted every 2 years if I still have her and can pull one of them for inspection then with a mind to having them replaced if it's got any worse.

Does that sound sensible?

 

[Hood]

Confirmation that the deep sea seals are connected to the cooling system on the engines, so as long as the engines run then the water in the shaft tubes should be oxygenated.

View attachment 319994
I'm thinking of pickling paste and passivating the shafts and putting them back in. I'd plan to have her lifted every 2 years if I still have her and can pull one of them for inspection then with a mind to having them replaced if it's got any worse.

Does that sound sensible?

Some of the fishing boats shafts are way worse than yours and that is after they have been pulled and inspected for their DTI and passed, so I don't think you have anything to worry about.

 

[bert]

Some of the fishing boats shafts are way worse than yours and that is after they have been pulled and inspected for their DTI and passed, so I don't think you have anything to worry about.

I cannot express how happy your reply made me. I have been so worried that I would need new ones made and you have just put my mind at absolute ease.

 

[Misterg]

I only have experience of little engines in sailing boats, but I wouldn’t worry about those shafts (especially if she is to remain a river cruiser).

I find it slightly odd that the pits are where the shaft was exposed (albeit inside the stern tubes) - my limited experience is that it is not uncommon to see crevice corrosion on shafts where they pass through the cutlass bearing if the boat has been left in the water un-used, but that the rest of the shaft is usually untouched.

It may well be that your pitting is electrolytic in origin.