The galvanizing reaction will only occur on a chemically clean surface. Therefore most of the preparation work is done with this objective in mind. In common with most coating processes the secret to achieving a good quality coating lies in the preparation of the surface of the iron or steel. It is essential that this is free of grease, dirt and scale before galvanizing. These types of contamination are removed by a variety of processes. Common practice is to degrease using an alkaline or acidic degreasing solution into which the component is dipped. The article is then rinsed in cold running water and then dipped in hydrochloric acid at ambient temperature to remove rust and mill scale.
(Welding slag, heavy paint (such as epoxy, liquor, etc) and heavy grease will not removed by the above cleaning steps and should be removed before the work is sent to the galvanizer, otherwise additional shot blasting cost may be charged.)
After a further rinsing operation, the components will then commonly undergo a fluxing procedure. This is normally applied by dipping in flux solution - usually zinc chloride and ammonium chloride at around 65-80ūC. The fluxing operation removes any of the last traces of oxide from the surface of the component and allows the molten zinc to wet the steel.
