With the latter method, either an aesthetic goal is chosen (think chromium plating) or the goal is the long-term protection of steel from rusting. In this case, zinc is the metal of choice because, in addition to providing a barrier, it also provides cathodic protection for the steel. In addition, a zinc coating is also very wear-resistant. However, there are different methods of applying the zinc layer to the steel. It is important to know the differences to avoid making the wrong choices.
Hot-dip galvanizing (also called discontinuous hot-dip galvanizing or piece galvanizing) is not only the oldest (first proposed by Frenchman Paul Jacques Malouin in 1742), but also still the most durable and effective method. Unfortunately, there is a great deal of confusion about the correct designation(s) of the various methods.
Often, in an order specification or in a quotation, only the word “galvanizing” is mentioned. One then usually means the discontinuous hot-dip galvanizing when it concerns an outdoor situation, but one then receives, for example, continuously galvanized materials. The latter material cannot match the discontinuous hot-dip galvanized steel in terms of durability and is guaranteed to lead to unwanted additional maintenance costs. In other cases, such as a bridge construction, the objects are so large and heavy that they simply do not fit into a galvanizing bath. Even then one will have to describe the proper method of galvanizing. Many parcel delivery carts are usually composed of some sort of frame which is electrolytically
galvanized. Given the relatively short life of these carts, a very durable preservation method is not necessary.
The table below lists the correct designations used by the industry, as well as accepted alternative designations. To avoid confusion when prescribing a galvanizing method, it is strongly recommended that – in addition to the correct designation – the correct standard be listed.