I chisel at it with a big flathead when it gets too fouled. Takes about 30 seconds.You might want to take a wire brush to the grouper. All that whitish stuff is zinc oxide and other compounds that insulate the zinc from the water making the zinc less effective.
Anyone who looks at my shaft zinc (anode) in the pic will agree it was on there a little long. This was my first year with this particular boat in this harbor, after moving her here from the east. Probably better to limit the shaft zinc time in use to 6 months.We sailors can be an odd group. We think little of throwing down $15 for a 12 pack of craft beer that just ends up in the water we're sailing in, but try to stretch the life span of an anode that costs about the same. Once the anode starts to fail those electrons start looking for other sources of very expensive to replace metal.
And then there are those freshwater sailors who put a zinc on their prop shaft and 10 years later brag about how well it is holding up, looks like new they say.
Sometimes we northern sailors forget that southern and warm water boats stay in the water for a year or more between haul outs. And those of us who take their masts down every fall don't always know why the rest of you get so nervous about taking the mast down.....Anyone who looks at my shaft zinc (anode) in the pic will agree it was on there a little long. This was my first year with this particular boat in this harbor, after moving her here from the east. Probably better to limit the shaft zinc time in use to 6 months.
Although, that's why I use the grouper, in case the other stops working before I notice. Hang it off the backstay, which is bonded to the engine/through hulls/other rigging.
Am in the water year round, so changing the zinc is more of a task than just buying it. I have my diver monitor /change if needed when he cleans the bottom, but he's only down there about once every three to four months - I keep the bottom clean with sailing ;-)
Try three years or more...Sometimes we northern sailors forget that southern and warm water boats stay in the water for a year or more between haul outs.
Yes, I agree "that puppy is done".Dalliance: your zinc was 50% effective at best after 5 mo. (Season 1), and completely salted up after 10 mo. (Season 2). That puppy is done. What does your prop look like?
Gunni,Ok, Great! Can you provide a report on your use of Lanocote? I get variable results with zinc spray, looking for something more effective against hard growth.