I plan on installing a couple of zinc anodes on my rudder head plates to prevent further corrosion of the lower ends. My question is whether these anodes need to contact the water to be effective. It is only the lower inch or so of the rudder head which normally contacts the water; I''m assuming I need to have the anode in this area, and that a disc anode mounted on the pivot bolt of the rudder (which is up above the water surface) will offer ineffective protection. I guess a tear-drop shaped anode would work best along the lower edge of the rudder head plates.
A sacrificial zinc anode must be in contact with the seawater to be effective.
A single zinc anode, of the appropriate size, will protect all immersed metals that are electrically connected (bonded) to it.
Rudder shafts often have a poor electrical connection to the boats bonding system, due to high resistance through the rudder bearing.
Regards,
Gord
This is a transom-hung rudder, pintle and gudgeon, what is corroding are the two plates that form the rudder head (the rudder itself is fiberglass laminate over wood, presumably, and it pivots in the rudder head).
Linear Mode
