Sharing the lessons - #5 - If you think it's difficult, zinc again
It's been a while since our last "Sharing the lessons" post, but we have a few new ones lined up if I can just stop long enough to write them.
While underwater, cleaning the hulls after we had left Lady Roslyn for a few weeks to return home, I noticed that our propeller zincs were almost completely corroded away. The sail drive zincs are fine but the propeller zincs definitely needed replacing.
We last lifted Lady Roslyn from the water 18 months ago in Athens and we do not intend removing her again until winter 2020.
For anyone who might have a similar issue, this is what I did to replace the zincs.
The total job for both zincs took around 20 minutes.
Volvo new propeller Zincs - set of 3 semicircular pieces with 3 hex headed screws
Dive tank, mask, weight belt and fins (we have a hookah rig onboard so I can leave the tank on deck. We connect the tank to a regulator with 25 metres of hose, which allows me to swim completely around and underneath Lady Roslyn when needed)
Bucket with rope attached to the handle
Place all spares and tools into the bucket and fill it with water. Dive under the boat and tie the bucket rope around the propeller cuff so that it is as close to the cuff as possible and directly below the zinc slot. The bucket is there to hold all the things you need, but it is also there to catch a zinc piece or screw if you drop it.
Remove old screws and remaining zinc. I found some growth buildup in the zinc slot which needed the screwdriver to scrape out. After scraping it clean, use the scouring pad to give the slot a good polish so that the brass shines and creates a good contact for the new zincs.
Fit the 3 new zinc pieces one by one and tighten the hex screws properly.