Pros and Cons of Prop Anode Zincs

I have no space for a shaft zinc on my boat (besides the two on my rudder post).

I do have a anode on the end of the shaft=acorn shaped that has a center hex bolt.

As the zinc dissolves I noticed the hex bolt needs retightening. Is that normal or am I waiting to long to change it?

During my Winter in water layup I hang a large zinc overboard wired to the rudder post, prop shaft and bonding system.

If I installed a zinc block on the transom could I do away with prop zinc set up?

Just planning haul out- to do list.

JohnP

JohnP wrote:

I have no space for a shaft zinc on my boat (besides the two on my rudder post).

I do have a anode on the end of the shaft=acorn shaped that has a center hex bolt.

As the zinc dissolves I noticed the hex bolt needs retightening. Is that normal or am I waiting to long to change it?

During my Winter in water layup I hang a large zinc overboard wired to the rudder post, prop shaft and bonding system.

If I installed a zinc block on the transom could I do away with prop zinc set up?

Just planning haul out- to do list.

JohnP

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I have both a shaft zinc and an acorn size H on the tail. mine does not erode under the bolt head at a rate that causes loosening. Maybe you aren't changing it often enough.*

I would not go without that acorn. Your prop will become the anode.


-- Edited by Carey on Thursday 17th of February 2011 09:31:40 PM

JohnP: As Carey has, we also have the size H prop nut anode. We have never had to tighten them up. Check the cotter pin that holds the nut on to make sure that it doesn't interfere with the seating of the anode. If the anode doesn't sit square on the nut, I could see where it could loosen over time.

Larry/lena
Hobo KK42
Puerto Madero, Chiapas, MX

I have two hanging from the Eagle, one connected to the bow thruster as its metal and one from the engine room.* The reason is the current is very small and reduces the further away from a zinc as the zincs are at each end of the boat, 45 to 50 ft away. The bow thruster zincs are small, the first to go and last about 6 months, so they are almost gone by the time they get changed, and its a long run from the bow to the stern zincs.* The one on the engine room is mid way and is to double protect.* They do seem to make the other zincs last longer. *


*
As for a shaft zinc they make a shaft brush that rides on the shaft in the engine room that connect to the zinc loop, cost about 40 bucks.* I have seen them on several new boats.*

I have the same setup and have never really noticed any loosening. Well, except for one time where the diver didn't put it on correctly and the whole thing was gone, bolt and all.

When you put the zinc on, remember to seat it with some light taps with a hammer. Tighten the bolt again, light taps until you get all the slack out. When I do it out of the water, I also use a little blue loctite on the bolt.

Phil Fill wrote:
I have two hanging from the Eagle, one connected to the bow thruster as its metal and one from the engine room.The reason is the current is very small and reduces the further away from a zinc as the zincs are at each end of the boat, 45 to 50 ft away. The bow thruster zincs are small, the first to go and last about 6 months, so they are almost gone by the time they get changed, and its a long run from the bow to the stern zincs.The one on the engine room is mid way and is to double protect.They do seem to make the other zincs last longer.
As for a shaft zinc they make a shaft brush that rides on the shaft in the engine room that connect to the zinc loop, cost about 40 bucks.I have seen them on several new boats.

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I failed to mention in my previous post, that my electrician convinced me to add the shaft brush many years ago. It may seem like overkill, but I now have the acorn on the tail, a shaft zinc about a foot up the shaft, and just inside the engine room is the spring loaded brush, which is tied into the bonding system. It's doing the job.

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