Hot-dip Galvanising is the process of immersing a steel or iron piece of metal in the molten zinc bath and heating it at 449° C which results in the deposition of a thin layer of Zinc on top of the base iron or steel metals forming an iron-zinc and steel-zinc alloy. Hot-dip galvanization uses chemicals like Zinc ammonium chloride as flux which is applied onto steel objects to avoid the corrosion of clean steel by the atmospheric air. This process exclusively uses Zinc as it has a high corrosion resistance tendency which makes it last longer, protecting the metal surface.
Metal coloring is the usage of chemical solutions to impart different colors onto the metal surface. Metal coloring is a complex process and transferring of colors onto metal surfaces depends on the types of metals, therefore different processes are involved like anodizing the metal, patination, etc. There are various Metal colouring chemical solutions, each with different chemical constituents as metals react differently to different chemicals, like, Tin chemicals, Nickel chemicals, etc. Metal coloring is done to give a different look to metal objects like a vintage touch or golden patina or provide renewed luster to old metal objects of importance.