AIFO ANODE PLUG DAY 14

Function and technical context

The Aifo anode plug with a diameter of 14 mm is a cathodic protection element designed to be installed at the drainage or emptying points of the engine block, acting simultaneously as a watertight seal and as a galvanic sacrifice. Its function is twofold: on the one hand, it seals the hole in the cooling circuit or block, preventing water or coolant leaks; On the other hand, the anode material of the plug corrodes preferentially against the structural metals of the engine, protecting the block, cylinder head and other metal components from electrochemical corrosion caused by salt or brackish water. In Aifo family engines—used in work boats, professional fishing and recreational use—correct cathodic protection of the drain points is essential to maintain the integrity of the seawater cooling system and prolong the life of the engine. A deteriorated or exhausted anode cap leaves the base metal exposed to galvanic corrosion, which can lead to pitting in the block, leaks in the cooling circuit and breakdowns that require high repair costs.

When to replace this part?

Sacrificial anodes – including threaded anode plugs – should be inspected at the beginning and end of each boating season, and replaced when they have lost approximately 50% of their mass or show significant visible wear, without waiting for them to be completely consumed. In high salinity environments or with high eddy electrical currents, wear can accelerate and require intermediate revisions. Replacing the anode plug preventively at each annual beaching is the practice recommended by naval mechanics: the cost of the replacement is minimal compared to a block or cylinder head repair due to advanced corrosion.

Compatibility table