Compatibility and incompatibility in anticorrosive painting: The particular case of maintenance painting

Despite being one of the most widely used anticorrosive protection techniques, painting often leads to incompatibility problems. Maintenance painting is also a common technique in the anticorrosive protection of metallic structures and equipment in general. When the maintenance work to be performed foresees using an old (aged) coating as an integral part of the new paint system to be applied, it is of vital importance to ensure the compatibility of the different components. Otherwise, premature failure, (bleeding, lifting blistering, cracking, etc.) may occur in a short time period. Using a previously defined methodology, this paper studies the behaviour of a number of new paint systems applied on aged paint coatings containing different types of finishing paints. Through the performance of accelerated and non-accelerated ageing tests it has been possible to select the new paint systems that are most suitable for application on old (aged) paint systems, thus allowing a reduction in the risk of incompatibility between the two.