COLLARIN EJE 1 1/8" USA (ZN)

Function and technical context

The 1 1/8" zinc shaft collar is a cathodic protection component that is installed directly on the boat's drive shaft, acting as a sacrificial anode in the submerged area of the propulsion system. Its main function is to protect the shaft, propeller and adjacent metal elements against galvanic corrosion generated by the difference in electrical potential between different metals in contact with water. Being manufactured in zinc, it is especially suitable for use in salty and brackish waters, where the electrochemical aggressiveness of the medium is greater. A worn or missing collar exposes the propulsion shaft to accelerated corrosion that can compromise the structural integrity of the shaft, cause abnormal vibrations in the transmission line and even lead to serious breakdowns of the propulsion system.

When to replace this part?

The most obvious symptoms that the zinc collar has reached its useful life are a visible reduction in its mass of more than 50%, the appearance of pitting or corrosion on the tail shaft itself, or the presence of unusual vibrations related to uneven wear in the propeller area. It is recommended to inspect and replace the zinc anodes at each seasonal tune-up or at least once a year if the boat remains in the water continuously; In waters with high conductivity or stray currents, wear can be significantly faster. Replacing the collar preventatively is the most economical measure to avoid costly replacement of the drive shaft or damage to the horn and water bearing.