ANODE SHAFT 3

Function and technical context

The shaft anode is the component responsible for cathodic protection of the transmission shaft submerged in water, whether salty, brackish or fresh with dissolved minerals. It acts as an electrochemical sacrifice: being a more active metal (generally zinc or aluminum), it corrodes in a controlled manner instead of the axle, propeller and other metal parts of the drive train. Without this protection, galvanic corrosion would directly attack the stainless steel or bronze shaft, compromising the structural integrity of the transmission and potentially causing vibrations, loss of tightness in the stuffing box or even fracture of the shaft while sailing.

When to replace this part?

Shaft anodes must be inspected at the beginning and end of each sailing season, and replaced when they show wear greater than 50% of their mass, at which time their protection capacity decreases significantly. An excessively consumed anode is visually identified by its porous, reduced or disintegrated appearance; If the shaft begins to show superficial pitting or irregular coloring, it is a sign that the anode has stopped protecting it properly. Replacing the anode preventively at the beginning of the season is the most economical measure to avoid replacing the shaft or propeller, considerably more expensive repairs that can leave the boat immobilized.