Choice of coating system
ANTI-CORROSION COATINGS ( CATEGORIES AND SERVICE LIFE OF THE OBJECT)
To protect steel from environmental influences, corrosion protection by coating is the best, and often the only, option. Coatings are specially adapted for different application scenarios. It is very important to choose the right and suitable system. For example, the corrosive environment in an outdoor stadium is higher than in a school building. In addition, the rate of corrosion also increases near a river or seashore or in tropical climates with high humidity and temperature.
These environmental influences are governed by the corrosiveness categories in the ISO 12944-2 corrosion protection standard.
Maintenance and repair of anti-corrosion coating systems are important factors in the economic efficiency of steel structures and in improving environmental protection.
EN ISO 12944 also defines the durability of a coating system, taking into account the corrosive load in the environment and the expected time until the first full recovery of the selected coating system.
The standard distinguishes four time periods of durability:
- low up to 7 years
- average from 7 to 15 years
- high 15 to 25 years
- very high for >25 years.
The technical name “durability” is intended to help customers plan or define repair and refurbishment programs. However, these classes are not guaranteed periods
Surface preparation is essential for optimum results. The type and intensity of surface preparation must be adapted to the initial condition and expected load. With the right degree of preparation, the durability of the coating can be increased. Part 4 of ISO 12944 divides the initial condition into three grades from rust grade A to rust grade C. This leads to the corresponding preparation grades such as Sa 2 1/2.