Cathodic Protection

Basics

• Also referred to as "Galvanic Protection" although this is more of a technique OF Cathodic Protection
• Allows for Oxidation to be sort of "rerouted" to a remote Sacrificial Anode and thus making the structure into a sort of Electrochemical Cell
• This is often done with a Zinc Sacrificial Anode, but technically Galvanization also uses the same mechanism (althouh it isn't often referred as Cathodic Protection in everyday use to provide more clarity)
• Most Boats use this for propellors, and other water exposed metals
• This is also very common for Pipeline Transport due to the expense of replacement
• Rebar is another use case
• The Sacrificial Anode can be directly attached (Usually via screws/bolts onto a clear surface), or remote via wires
• It is thus easily exchangable
• The Sacrificial Anode is gradually spent as it is oxidised, and thus must occasionally be replaced
• This does lead to more Lifelong Design when compared to simple galvanization (Need to research how it compares to stainless steel etc)

Methods

Galvanic

• Galvanization or use of a Sacrifiical Anode

Impressed Current

• An "Active system" uses current flow to accomplish the goal

Hybrid Systems

• Uses both galvanic and active methods

See Also

• Open Source Universal Zinc Sacrificial Anode
• Protective Metal Coatings

Useful Links

• The Wikipedia Page on Cathodic Protection