Of metallic structure anticorrosion commonly used have two kinds commonly, it is hot gush zinc, another is coating rich zinc paint (only to chemical activity compares zinc poor useful oh!) In fact, the principle of both is the same, using the principle of electrochemical reaction, to sacrifice the anode (zinc layer or zinc powder). Hot spraying zinc is the metal zinc (generally zinc wire, like iron wire, very soft) with plasma high temperature (gun head) in the form of melting spray to the surface of the metal, and then spray a layer of anticorrosive finish, finish paint a lot of types, generally with epoxy asphalt type on the line. There are a lot of zinc powder in rich zinc primer, spray layer rich zinc primer and hot spray zinc effect is about the same, finish paint is generally used epoxy asphalt type on the line. Zinc was chosen because it is relatively cheap.