Corrosion protection for steel and aluminum components through painting

Corrosion protection through painting: How coordinated paint systems protect steel and aluminum components in the long term - wet painting, coating structure and practical approaches for durable industrial components.

Whether outdoor steel structures, machine housings or high-quality aluminum components: Without reliable corrosion protection, metal components are at risk sooner or later. This can have serious consequences, especially in industrial applications: Rust weakens the material, impairs the appearance and causes high maintenance costs. This makes it all the more important to have a well-thought-out coating system that is tailored to the material, application environment and desired duration of protection. Stoz GmbH has been a partner for precise wet painting for almost 100 years and advises customers from the selection of a suitable paint system through to professional implementation.

Corrosion describes the attack of metal by environmental influences, usually in the form of moisture, oxygen or chemical substances. In the case of steel, this process quickly leads to visible rust. This creates a porous iron oxide layer that weakens the component and does not stabilize itself. Without additional protection, corrosion will continue.

Aluminum, on the other hand, forms a natural oxide layer that initially has a certain protective effect. However, under unfavorable conditions, such as salty air or contact with other metals, aluminum can also corrode. In both cases, without a suitable coating, components lose their service life, functionality and value retention.

Corrosion protection by coating is based on two fundamental principles:

1. passive protection: the barrier effect

The shielding effect of the paint film is the main focus here. The coating separates the metal from moisture, oxygen and chemicals. The denser and more uniform the film, the more effective the protection. Wet paints offer great flexibility in terms of coating thickness, color and gloss level. This is ideal for functional and visual requirements.

2. active protection: protection through a sacrificial layer

With active corrosion protection, special primers, such as those based on zinc, have an electrochemical effect. They "sacrifice" themselves before the steel is attacked. In this way, the underlying component remains protected.

Different paint systems are used depending on the application: epoxy resin paints offer very good adhesion and chemical resistance. Thanks to their dense, well-crosslinked structure, they create a high barrier effect. They are available both as purely passive systems and as active zinc coatings. However, epoxy resins are not UV-stable, which is why they are only suitable for durable outdoor applications to a limited extent.

Polyurethane top coats are UV-resistant, abrasion-resistant and durable. They are particularly suitable for components in outdoor areas or with high visual requirements. In practice, multi-coat systems are often used, such as a combination of epoxy resin primer and polyurethane topcoat. This allows the advantages of both systems to be optimally combined.

Stoz GmbH specifically uses wet paints. They adapt excellently to complex geometries, enable fine surfaces and can be individually tailored to customer requirements, both for individual items and in series painting.

The decisive factor for long-lasting corrosion protection is not only the paint itself, but also the interaction between the material, environment and coating system. Sound advice and professional implementation ensure that steel and aluminum components remain permanently protected (OM-4/26).