Kylmäsinkitys

Kylmäsinkitys, also known as cold galvanizing or zinc-rich coating, is a method of applying a protective zinc coating to metal surfaces. It involves using a paint or coating that contains a high percentage of zinc dust, typically over 90% by weight. This zinc dust is suspended in a binder, which can be organic, inorganic, or a combination of both.

The application process for kylmäsinkitys is similar to painting. The metal surface must be properly prepared, usually by cleaning and degreasing to remove any rust, scale, or contaminants. The zinc-rich coating is then applied using methods such as brushing, rolling, or spraying. Once dried, the coating forms a protective layer.

The primary function of kylmäsinkitys is to provide cathodic protection to the underlying steel. When the zinc coating is exposed to the environment, it corrodes preferentially to the steel. This sacrificial corrosion means that the zinc is consumed while the steel remains protected from rust. This is analogous to hot-dip galvanizing, but typically offers a lower level of protection due to the thinner zinc layer and less robust adhesion.

Kylmäsinkitys is often used for repairing damaged hot-dip galvanized coatings, as a primer for subsequent painting, or as a standalone protective coating in less aggressive environments. It is a convenient and cost-effective option for many applications where the extensive preparation and higher cost of hot-dip galvanizing are not required. However, its effectiveness is generally considered to be less durable and protective compared to hot-dip galvanizing, especially in harsh industrial or marine conditions.