Preparation of Metals for Painting

It has long been recognised that the durability of a paint finish is largely dependent on the condition of the metal surface beneath it. Complaints of poor durability, blistering and formation of rust are often the result of inadequate surface preparation and have no direct bearing on the quality of the paint itself. Good preparation of a metal surface is known to be essential prior to metal spraying or electroplating, and very quick failure by flaking will occur if the surface is not correctly prepared. Unfortunately, with paint, it is possible to ‘get away with it’ temporarily and hide surface defects; but before many months have passed the paint will fail and complaints are likely to be made against its quality. This comprehensive article surveys present‐day techniques in the preparation of metals for painting and includes sections on the testing of results, economics and design considerations.