Coatings

According to studies carried out by independent entities, the most effective system for the protection of the steel used today is the duplex system. These studies show that the corrosion resistance of a steel protected according to the duplex system is much greater than that which would be obtained if we add the duration of each system component of it separately. In other words, a galvanized steel only and a painted steel on a non-galvanized base. This is because the paints have a degree of porosity that allows the water to get through and reach the steel.

When this steel is not galvanized, iron oxide and corrosion is produced and that increases the volume, lifting the paint and speeding up the process, if there is a galvanized base underneath, the zinc oxide will produce a protective layer that will clog the pore of the paint but without uprisings, stopping the corrosion. In the case that it is only galvanized, we also have less protection since zinc is exposed to external agents directly, so Zinc oxide is produced much more easily and the protective layer doesn’t last too long.

1. Coating on non-galvanised steel. Once the water gets in touch with steel, rust (iron oxide) increases in volume and cracks the paint, accelerating the corrosion process by easing the access of corrosives to the surface of steel.
2. Coating on galvanised Steel. When water gets in touch with the galvanised steel surface, zinc oxide acts as a corrosion protection, preventing the coating deterioration.

Our R&D department has developed various epoxy and polyurethane coatings to meet specific requirements depending on use. Some of the most impressive performance requirements of the ILURCO coatings includes: a high adhesion to galvanised surfaces that it is second to none and an outstanding elasticity, which is higher than regular coating international standards. These properties make of ILURCO coating the ideal choice for a broad number of uses under extreme conditions, protecting surfaces from micro-cracking and the damage responsible for corrosion. This coating meets are applied inside the factory using a chain automatized process following  EN ISO 12944-5 (2018) regulation.

STRUCTURE OF THE DUPLEX SYSTEM (SAME IN BOTH SIDES)

Application limits inside the  EN ISO 12944-5 (2018) regulation are shown in the next tables. As well as the Ilurco Coatings used to comply with it.

ILURCO’s R&D recommends the Duplex System (galvanising + epoxy) for low or medium corrosivity categories, described in the regulation as C2 and C3 (ie. Clean or hard water). For high and very high corrosivity categories as C4 and C5, the regulation recommends applying a priming coat and one or two epoxy finishing coats.

This is ILURCO’s TRIPLEX SYSTEM that consists of the application of three coats: galvanising, priming coat and several finishing coats. As priming coat, ILURCO’S R&D has developed ILURPROXI BASICO that offers a high waterproof protection with high film thickness and excellent adherence on galvanised surfaces. It is suitable to be used with a wide range of coating products. Besides, it provides a high impermeability to water.

On this primer layer, one or two coats are applied, depending on the use, of the most convenient coating depending on the water to be contained, which allows us to fully exploit the best properties of each product. The finishing layer is responsable for resisting the most aggressive elements contained in the water and from the primer coat, the adherence between the base and the finishing layer.

STRUCTURE OF THE TRIPLEX SYSTEM