All of Zaun’s gates and railings are hot-dip galvanised to BS EN ISO1461:1999. Hot dip galvanising is a dipping process in which fluid zinc alloys to the steel surface. The zinc will penetrate all recesses and open hollow surfaces. Hollow tubes like posts and gate frames are ‘vented’ which means that zinc can flow inside the tube, meaning that a protective coating is applied to the inside of the steelwork as well as the outside. Prior to dipping, the steelwork first goes through 17 stages of pre-treatment. Firstly this involves 6 acid tanks of increasing strength, which degreases the surface and remove impurities. The steel is then rinsed in ion-free water before being heated to 70 degrees in the flux tank, during which will evaporate all water from the steel. The steel is then dipped in the zinc tank, during which will a flux solution is sprayed on the steel to help zinc flow over the metal. The galvanised metal is then removed from the tank at a specific angle to help excess zinc flow off. The metalwork is then cooled in water prior to fettling, if required.
|Galvanising thickness of hot dip galvanised products|
|Steel Thickness||Minimum Coating (Grams/m2)|
|1.5 – 3.0mm||395|
|3.1 – 6.0mm||505|
|6.1mm and Over||610|