One of the most common problems we see on mega yachts is crevice corrosion and wear on stainless steel shafts, whether those shafts are propeller, rudder or NAIAD stabilizer shafts. Stainless steel shafts can be damaged by excessive wear in contact areas, such as bearings or seals due to long life or misalignment. Shafts can also be damaged from crevice corrosion or stray current corrosion.
The solution to these problems can range from cladding the existing stabilizer shafts or fabricating entirely new units. Cladding or shaft weld-over, is the process of repairing a worn or damaged area on a shaft. This type of work is done by our on-site machine shop, Straight Line Marine, which is the only shop in Florida that is ABS approved to perform this type of work on propeller shafts. Replacing a large NAIAD stabilizer shaft would cost thousands of dollars, depending on the size. However, the cladding repair is less than a thousand dollars.
This was the case on a 145 foot Trinity yacht that we were working on rebuilding its NAIAD Stabilizer System. When pitting or crevice corrosion becomes too extensive, it prevents the lip seal from establishing a tight fit thus allowing sea water in or oil to leak out of the system.
We removed the shafts, cladded them and installed new lip seals in the NAIAD Stabilizer and the owner was good to go.