I am some what familar with Cathodic protection as applied to metal buildings, ship hulls, etc.
Typically the structure we are trying to protect is considered the cathode, and an external anode material is connected by wire to the structure. The anode is sacrified (deteriorates) as current (Conventional) flows from the anode to the cathode. Typically othe structure should be more neg, beyond -.85V. If this can't be achieved with supplied carbon anodes a power supply is put in series to aide in process. Magnessium anodes normally don't require extrnal power supplies.
My question: in a boiler or hot water tank. the Anode is usually inside the tank as opposed to outside. Is it as simple as : one case we are protecting the outside of a tank and the other , the inside? Why does the anode need to be imersed inside as opposed to putting an anode on the outside?
Typically the structure we are trying to protect is considered the cathode, and an external anode material is connected by wire to the structure. The anode is sacrified (deteriorates) as current (Conventional) flows from the anode to the cathode. Typically othe structure should be more neg, beyond -.85V. If this can't be achieved with supplied carbon anodes a power supply is put in series to aide in process. Magnessium anodes normally don't require extrnal power supplies.
My question: in a boiler or hot water tank. the Anode is usually inside the tank as opposed to outside. Is it as simple as : one case we are protecting the outside of a tank and the other , the inside? Why does the anode need to be imersed inside as opposed to putting an anode on the outside?