ANODO POPA DISCO Ø 230 (ZN)

Function and technical context

The aft anode in a 230 mm diameter disc made of zinc acts as cathodic protection of the propulsion system, sacrificing itself electrochemically to preserve the noblest metal parts of the propulsion group—such as propellers, shafts and tail bodies—against galvanic corrosion. It works within the stern corrosion protection system, a passive but absolutely critical component on any outboard or inboard motor boat operating in salt or brackish water. Its large diameter circular geometry allows it to offer a large sacrificial surface, distributing protection evenly over the stern area. Without an anode in good condition, galvanic corrosion progressively attacks the structural metals of the propulsion group, potentially causing irreversible damage to high-cost components such as the tail shaft, propeller or transmission case.

When to replace this part?

The clearest sign that the zinc anode needs to be replaced is when it has lost between 50% and 60% of its mass: once that threshold is exceeded, the cathodic protection capacity decreases dramatically and adjacent metal components are exposed. As a general maintenance rule, zinc anodes should be inspected when the boat is taken out of the water and replaced at the beginning of each boating season or, at most, every two dockings, regardless of their external appearance. If corrosion on the propeller, pitting on the shaft, or metallic discoloration in the stern area is detected before reaching this interval, the anode may have exhausted its useful life prematurely, possibly due to eddy currents in the mooring. Renewing the anode preventively at each seasonal tune-up is the most economical measure to avoid costly repairs at the dock or, worse still, breakdowns at sea.

Compatibility table