Hot Dipped Galvanized Coil Hot-dipped galvanized coil refers to a product that is created by immersing steel coil into a bath of molten zinc. This process is known as hot-dip galvanizing and results in a protective coating of zinc being applied to the steel surface. How does the hot-dipped galvanizing (HDG) process work? This technique, also called HDG, is now a lot more common. Galvanizing is basically the process of adding a coating on any base metal for the purpose of increasing corrosion resistance and durability. Hot-dip galvanizing is a form of galvanization. It is the process of coating iron and steel with zinc. That is, the surface of the base metal is coated with a zinc layer by immersing the metal in a bath of molten zinc at a temperature of around 450 �°C (842 �°F). Galvanized steel is widely used in applications where corrosion resistance is needed. But its cost is much lower than the cost of stainless steel.