ANODE SHAFT 30 mm.

Function and technical context

Shaft anodes are fundamental sacrificial elements in the cathodic protection system of shaft-driven vessels. Its mission is to protect the metal drive shaft against galvanic corrosion that occurs when different metals are submerged in salt or brackish water. The propulsion shaft, being usually made of stainless steel or bronze, is especially vulnerable to electrolytic corrosion when it does not have adequate anodic protection. This 30 mm anode acts as a sacrificial electrode: being made of a metal with a more negative electrochemical potential (zinc or aluminum), it preferentially corrodes instead of the shaft, preserving the mechanical and dimensional integrity of the transmission.

When to replace this part?

The wear of a shaft anode is visible to the naked eye: when the anode has lost between 50% and 70% of its mass, it must be replaced immediately, since below that volume its protective capacity is insufficient. The review must be carried out at least at the beginning and end of each navigation season, or at each maintenance dock, being especially critical in areas of salt water or high conductivity. Replacing the anode preventively before it is completely consumed is the most economical measure to avoid shaft pitting and costly grinding or shaft replacement work that results from advanced corrosion.