Sail drive Leg and Prop spring maintenance

[CJRodriguez]

Hello fellow sailors, I have a 2019 Jeanneau Sun Odyssey 389 with a Saildrive.
I have been looking with no success how to clean and paint my leg and propeller. I could pay someone but I rather learn how to.

Thank you in advance for all your collective knowledge and help

[slug]

For general info this is the Yanmar saildrive service bulletin

https://www.yanmar.com/us/wp-content...-Corrosion.pdf

[DougR]

Was this propeller new when it was installed on the saildrive, or was it fitted from another application? From the photos it seems to me that the prop is suffering from "prop burns" or cavitation erosion. In the center of each blade face there is a spot where erosion is occurring, or has occurred in the past. Typically this occurs when low pressure vapor bubbles stream from a shaft, strut or saildrive leg and impact the prop blade face, where the pressure is high. The high pressure causes the bubbles to collapse and release energy onto the propeller face which erodes material from the prop. If this continues long enough it will eventually pit the blade and might even become severe enough to make holes in the blade.

The cause of the bubble formation can be surface irregularities, sharp edges, disturbed water flow, etc. In this case it seems that the water pickup openings in the drive leg align with the erosion, and it may be that the sharp edges of the openings are causing turbulence and low pressure bubble generation.

If this was my drive I would smooth and fair the water pickup openings while I was in the process of barrier coating and painting the drive. A little attention now might save some grief later. (Truthfully, if it were my sail drive I would epoxy putty the pickup holes closed and install a separate thru hull water pickup, but that's a different conversation...)

DougR

[CJRodriguez]

DougR, thank you so much for your knowledgeable response on this issue. Aquitania was commissioned and put on the water on July 15, 2019, and got out of the water for winter storage at the end of October. She has 125 hours on the engine. The propeller came from the factory and has not been touched since. Is this something I should contact Jeanneau as a Warranty issue?

[DougR]

The first thing I would do is examine the prop and make sure what I think I see in the photos is really there... Then, if it is there, I think I would explore with the selling dealer, or the importer, whether they have seen similar issues with the use of these aluminum props on similar vessels. I might also take the prop and drop by a reputable prop shop and get another opinion on possible causes. Perhaps there is something wrong with the prop that needs a pair of experienced hands and eyes to pick up.