Electrical Arc Metallization Equipment
The galvanizing spray process consist to spray molten zinc, finely pulverized, on the surface to be protected properly prepared with a suitable blasting to white metal (the degree SA3 SA 2,5 ). The spraying of zinc is performed with guns having a device for melting and pulverization and another device to feed the zinc. The merger is ensured by an electric arc.
The fluid spray is generally dry air and oil free, at a pressure of 0,27+0,54 MPa.
The Zinc is used in the form of wire, of diameter between 1,5 and 2,5 mm.
The excellence of the zinc is to form a dense and adherent film that has a very low corrosion rate (the 10 a 100 times less than the basic iron). Zinc is anodic to iron or steel base and sacrifice itself to protect them from rust when the surface is damaged
The spraying should be performed immediately after the blasting of the surface so that the same is still perfectly clean, dry and non-oxidized, in order to ensure the electrical contact zinc / iron, and then the anodic protection of the zinc. The duration of the coating depends on the thickness and the aggressiveness of the environment. Zinc ensures an effective corrosion in all environments in which the pH is between 6 and 12,5. The coatings obtained by spraying the electric arc differ from hot-dip galvanizing because they are more porous and composed of pure zinc. The porous coating accepts the sealants that penetrate into the pores and reduce the dissolution of the zinc.