Hot rolled galvanisation has two different methods to protect the steel against corrosion by using zinc. On the one hand there is Hot Dipped Galvanisation and on the other there is Continuous Strip Galvanisation.
Hot Dipped Galvanising or batch galvanising (according to the standard DIN EN ISO 1461) is a process in which the surface of the post is still black steel after profiling, and then batch submerged into liquid zinc. This process ensures that even the steel that has been cut on the post is covered by zinc. Here, the average zinc¹ covering is 45 µm. In practice, zinc thicknesses are measured between 60 µm and 80 µm. The galvanised surface is weather resistant for many years and guarantees durability for more than a generation.
For the continuous strip galvanising process (according to the standard DIN EN 10346), the liquid zinc is applied on the steel sheets before profiling takes place. This is what we call continuous galvanisation. Strip galvanised steel has a zinc covering of 275 g/m² (Z 275) per face of the steel. The average thickness of the zinc¹ here is 15 µm. In practice we measure zinc thickness levels between 20 µm and 25 µm.
Due to additional labour and a higher zinc layer thickness, the cost of a hot dipped galvanised post are around 20% to 30% more expensive than a strip galvanised post. If we consider that the average useful lifespan of a vineyard to be between 25 to 35 years, it is important to study the cost benefit factor over that time period. When comparing prices from different suppliers, pay special attention to the name of the type of galvanisation used. The term Hot Dipped Galvanised is often used to describe strip galvanised posts. In order to avoid any misunderstandings, we refer to our “Hot Dipped Galvanising according to DIN EN ISO1461” or “strip galvanised according to DIN EN 10346”. If you are not sure on the galvanisation of posts already purchased, cut off a piece of the post and send it to us. We will quality control and test the zinc¹ layer in house and let you know.