ABSTRACT
It is virtually impossible to predict the ‘life’ of organic coating systems from a knowledge of their formulations, even if these were available to users, which normally they are not. A good deal of performance data are available for metallic zinc coatings and, to a lesser extent, for aluminium, so it is possible to provide a reasonable assessment of their performance in many situations. It is not possible to provide similar data for organic coatings such as paint. Even within generic groups, there can be wide differences, so the performance of a paint supplied by one manufacturer will not necessarily be the same as that from others. Additionally, the performance of any paint is significantly influenced by the surface preparation of the steel prior to coating and the application of the paint. Hence, data on lives of coatings have to be obtained in one of two ways: (a) experience of a coating in a situation similar to that where it is to be used, and (b) by carrying out tests.
