The anode is the best protection for a boat from the corrosion of the metal parts that make it up. Aft engine, propeller, stern frame, knives, nails, hull. All these pieces corrode if they are made of brass, bronze, steel or aluminum. The corrosive effects are very important in seawater, where the zinc boats are subjected to prolonged electrolytic and electrochemical phenomena.
What is an Anode Used For?
Seawater causes significant corrosive effects due to electrolytic phenomena; the electric currents that cause them are generated by differences in potential between metal parts and water especially salt water that creates electric fields and therefore consumes matter. The consequence of these phenomena is the destruction of metal parts: there is a loss of material. To avoid such phenomena, it is useful to have an anode and replace it every year.
How to Protect the Boat
To protect these pieces, one or more metal elements are installed whose role will be to wear out instead of the boat. These elements are anodes. The alloy used contains 99.996% of zinc. They are not harmful to the environment. Thanks to the negative potential of the metal zinc, the anode will be attached instead of the other metal pieces in contact with sea water. It is, therefore, necessary to periodically renew this protection so that it remains effective.
In general, anodes must be changed every year, especially if they are continuously immersed in water. The use of a model conforming to the surface to be protected is recommended.
Rapid wear less than 3 months is abnormal; in this case, check that there are no electrical losses on the boat; this means the leakage of current through the hull due to a bad contact or electrical connection. If the anodes are not used, check that the propeller is not attached corrosion point or that it does not change color bronze propeller; the same goes for the propeller shafts, the iron seals of the rudder.
If the anodes do not perform their task, perhaps they have been badly fixed; consequently, the contact with the piece on which it is fixed is not ensured loose anodes, poor quality vines. Be careful never to paint an anode or the part of the boat it is in contact with, as failure to contact the parts to be protected, or the environment would make it totally ineffective. The standard anodes, the most commonly used, protect the elements common to all the boats, others are specific for the engines and are for the most part suitable for a particular brand.