ANODE SHAFT 3/4

Function and technical context

The shaft anode is a cathodic protection element that is installed directly on the propulsion shaft of the boat, acting as a sacrificial metal against galvanic corrosion produced by contact with salt or brackish water. Being manufactured with an alloy with greater electrochemical activity than the steel or bronze of the shaft, the anode preferentially corrodes, protecting the shaft, the stuffing box and other metal components of the transmission system. Without this protection, the shaft is exposed to accelerated corrosion that can compromise the structural integrity of the transmission and cause serious breakdowns in navigation. The CMC-1 reference is sized for 3/4 inch diameter shafts, one of the most common sizes in recreational and light-duty boats.

When to replace this part?

Shaft anodes must be inspected at least at the beginning and end of each sailing season, and replaced when they have lost approximately 50% of their mass, since below that volume their protective capacity is compromised. Symptoms of a depleted or missing anode include visible pitting on the shaft, corrosion on the stern tube bushings or bearings, and abnormal vibrations due to surface deterioration of the shaft. Replacing the CMC-1 anode preventively at the beginning of each season is the simplest and most economical measure to avoid costly damage to the transmission system that may force the vessel to be stranded out of port.

Compatibility table