replaced the zincs on my rudders this past spring. Ones on shaft had plenty of meat left and would have had to cut them off, didn't have enough time, never do!

Question when I had her hauled the zincs were gone!! all under water gear looked fine zincs on shfts looked the same. Could the zinc have vibrated off, should I have used locktite?

Replaced all the zincs in Boston. Pulled the boat out at Bayshore N.Y. everything gone. Found a bad 110v aire in the bildge problem fixed. Check inside your bildge for stray current put an amp meter between the bildge water and ground keep turning it lower until you get a reading. Unplug your dock feed and it should drop to zero if it does start tripping breakers until you isolate the source. If none of the breakers reduce the current, look between your shore power and breaker box.

I agree with what wes said.

Side note, zinc may look like they have a lot of meat on them, but could be soft, so when they went back in the water dissolved away quickly. New zincs every is standard practice.

I did not have zincs on my trim tabs when I got the boat, but noticed a descent amount of corrosion around the hinge area, I installed them and it stopped.

Don't have any zincs on the trim tabs, I only have zincs on the rudders and props shafts. As stated before the zincs on the rudders were gone bolts and all, gonna put new ones on this week for the upcomming season. Had the props serviced this spring (reduce vibration) hopefully the new zincs on the rudders will stay put this year....

quote:

Originally posted by nbpt:
replaced the zincs on my rudders this past spring. Ones on shaft had plenty of meat left and would have had to cut them off, didn't have enough time, never do!

Question when I had her hauled the zincs were gone!! all under water gear looked fine zincs on shfts looked the same. Could the zinc have vibrated off, should I have used locktite?

I would say the "sacrificial" aspect of the zincs was in play. Again the zincs are doing their job if they are eaten up. Your problem may be just that and you have a "stray electrical current" around you boat from your boat or another boat or electrical problems on the dock.
Also when you put on your zincs, tap them with a hammer after you have tightened their mounting bolt. then try and give it one more tight turn. You do not need locktite.