Cathodic protection is an electrochemical process which halts the natural reaction (corrosion) of metals in a particular environment by superimposing an electrochemical cell more powerful than the corrosion cell.
Sacrificial Anodes are fitted or bonded to the metal to be protected, this results in an electrical potential difference and the metal becomes cathodic causing the sacrificial anode to waste instead. In a correctly installed MGDUFF Cathodic Protection System corrosion only occurs to the sacrificial anode which is replaceable. The number and size of anodes is determined by the type of material and the surface area being protected.
Several factors determine the type of cathodic protection system fitted. Firstly the environment in which the vessel is operating, secondly the size and type of construction and finally the length of time that the vessel is likely to be afloat before the next maintenance slipping.
MGDUFF recommend the use of Zinc anodes for vessels permanently kept on a salt water berth.