Exterior zincs

[sandiegoguy]

I have a 4600 scb in saltwater, always plugged in.

The boat has shaft zincs, a transom zinc and trim tab zincs

I'm wondering if someone can share where they purchase theirs from, size and / or part #s. I know the shaft ones are just basic 2" ones.

Not sure the sizes on the transom or trim tabs.
I'd like to have them on hand for when the hull cleaner needs them.

Also, my shaft zincs only lasted 3-4 months which seemed pretty rapid.

[mmwjr]

The shaft zincs are doing there thing to protect the running gear. How quickly are the other shafts wearing?

Seems to either be a bonding issue in the boat or more likely stray current in the water where you keep it. this is also a safety hazard and should be looked into.

[HavaMax]

Boatzincs.com

[shrew]

How many shaft zincs on each shaft? I've seen folks stick two on each. Some even use a propnut zinc. Are there rudder zincs on the rudders as well?

Either the boat or the marina could have stray current causing the zinc's to wear quickly.

[sandiegoguy]

For future reference here are the exterior zincs my boat uses assuming other 4600s are the same.

(2) 2” collar zincs for the shafts-1 each shaft.
(2) MDR3 3¾” button zincs for the trim tabs-1 each tab.
(1) Diver’s dream plate zinc 12”x6”x.5”

I am in a shared slip and there is an old decrepit boat next to me that is for sale. I wonder if that caused the rapid zine deterioration. I did look up these zincs on boatzincs.com and they are about 60% cheaper than what I paid at the boat yard. Crazy!

I'll monitor and see how long these new ones last before investigating more. I will also see if my neighbor is plugged into shore power. I read something about installing some type of simple galvanic unit in the boat which helps greatly. Maybe my boat already has one?? I'll have to look into that more. Not sure of Maxum did this type of thing.

[shrew]

check you various seacocks and metal, especially those coming in conact with water or the exterior of the boat. Do you have a green wire bolted to metal on the seacocks? I assume these all go back to a galvanic isolator. This would also connect a green wire to the transom plate zinc as well.

your's and neighbors electrical cords draping into the water can cause this. As can old, poorly maintained neighbors. There are ways to determine if you have stray current in the water. You should be able to use a volt-meter.

[sandiegoguy]

Yes I have the green wires. I noticed them on the prop shafts but I will follow them and see if the go to a galvanic isolator. I'll have to look at the seacocks also. I'm going to see if my neighbor is even plugged in and if I ever see him I will ask more about his boat. It's an old trawler that is for sale and on it's last leg (visually).

I make sure my elec cord doesn't drape in the water.

So with the volt meter, any idea what settings I'd use?
how would i ground it?

[mmwjr]

The volt meter requires a special probe that is bought separately. You can google for the probe and directions on how to conduct the test.