ZINC BAR 40x400

Function and technical context

The 40x400 mm zinc bar is a sacrificial anode designed to protect the tailshaft of a vessel against galvanic corrosion in aqueous media. It acts within the cathodic protection system: since zinc is a more electronegative metal than the steel or bronze of the shaft, it preferentially corrodes, consuming instead of the structural components of the boat. Without adequate anodic protection on the shaft, electrolytic corrosion can silently but progressively degrade the driveshaft, horn seals and propellers, leading to high-cost repairs or even complete shaft replacement. This type of bar anode is especially suitable for installations in salt and brackish water, where galvanic activity is more intense.

When to replace this part?

Zinc anodes must be inspected at least once a season and replaced when they have lost approximately half of their mass, present cracks, surface detachment or the active surface is covered with calcareous deposits that prevent their correct performance. As a general rule in recreational boating and professional fishing, it is recommended to renew the shaft anodes at the beginning of each navigation season or after each winter, regardless of their apparent visual condition. Preventatively replacing the zinc rod before it is completely depleted is the most economical practice to avoid damage to the shaft, horn and propeller that forces the boat to be beached off schedule.

Compatibility table