Control of Metals by Protective Coatings

Protective coatings are specified in numerous national and international standards. For example, the extensive control description, ISO 12944 - Paints and varnishes -Corrosion protection of steel structures by protective paint systems - deals with the protection of steel by paint systems and covers in eight parts more or less all features, which are important to achieve good corrosion protection [5.108]  

Part 5 gives, in the primer area, information about the type of primer to be used for the different corrodibility categories (classification of environment according to Part 2) and indicates whether the primer is zinc-rich or based on other anticorrosive pigments. For example, ISO 12944-5 requests for a zinc-rich primer a zinc dust content of 80% by mass (m/m) related to the non-volatile content of the primer [5.108]. 

Resin systems for primers according to ISO 12944-5 are alkyds, chlorinated rubbers, acrylics, polyvinyl chlorides, epoxies, ethyl silicates and polyurethanes [5.108]. 

In ISO 12944-6, a method is described for evaluating the quality of a protective paint system by means of laboratory tests, which enables the user to select the most suitable test methods [5.108]. 

ISO 12944 gives planners, consultants and companies working on corrosion protection state-of-the-art information in concise form [5.108]. 

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