Another zinc question - rudder zincs on a trim tab

[estebanj]

My trim tabs have 3" rudder zincs... but only the top half with the nut in it. The screw comes through from the bottom of the tab.

Just to check, to replace I need to buy normal rudder zincs which comes in two halves, and I will discard the half w/out the nut. Correct? I cannot find "single half" round zincs for the trim tabs.

Just want to make sure I'm not looking for an item that doesn't exist.

Thanks,

Esteban

 

[osd9]

I use both halves on each tab.....why throw away all that protectiton....

 

[estebanj]

I was thinking the bottom half could interfere with "tab dynamics" with the water flow?

The boat came from the dealer/factory with only one half on the top.

Esteban

 

[Dave S]

You may not need to replace those for several years. They do not deteriorate very quicky.

 

[estebanj]

Hmmm... now you have me worried. Boat's a month old and the trim tab zincs look "used"... maybe 10-25% gone. The anodes on the outdrive look fine (0% gone). The prop shaft anode is missing.

Esteban

 

[Four Suns]

My tab zincs don't last long when I'm in saltwater either.... you are probably fine. Unless you have some old crap boats in your marina that are using your grounding and then zincs go really fast.

 

[Petep]

I had heard the same thing that Gary was referring to- Stray current in your marina can eat those zincs, even more so in salt water. I have heard of a way you can "measure" for how much stray current is in the water near you but can't think of how you would do it, I know you hang over some type of a meter. Maybe someone else has had this problem and will give us an education. By the way, I only have tab zincs on the top also. Mine have alot left so I have not replaced.

 

[estebanj]

Merc has its own, but here's another:

http://www.boatzincs.com/corrosion-reference-electrode-specs.html

You basically need a digital multimeter and the electrode to drop in the water not far from the outdrive.

Esteban

 

[Robski97]

I have to haul my boat mid season to rezinc....

I think every boat in my marina has there popwer lines laying in the water.... I complained till im blue in the face.. no one cares...


Rob

 

[gerryb]

Don't throw away the other half of of the rudder zinc. And don't put both pieces on the tab ans the bottom piece won't last once you get on plane. You can use the 2nd piece the next season. YOu will need 1) the other zinc piece (without the nut), 2) a nut for the screw you are using on the tab which is the same size as the nut in the other zinc and 3) a hammer. I put the other half of the rudder anode on a flat surface and then place the nut on top of the small opening at the center. With a few sharp blows of the hammer, the nut will go into it slot and work itself to the right shape on the zinc as it made of a soft alum alloy. I only go about 60% of the way through so that part of the nut still extends out from the zinc, allowing me to tightened with an adjustable or box wrench.