Coatings update: Scientific studies Part 2 Available to Purchase

The overall concept of permeability in paint films has been reviewed by Boxall and von Fraunhofer [Paint Manufacture, 45, November (1975) p. 14] who point out that as a result of their research the efficiency of anti‐corrosion pigments is closely related to water permeability in the paint film. Indeed, pigments like basic zinc chromate are only cabale of inhibiting substrate corrosion when in contact with water. This raises an interesting question relative to the effectiveness of anticorrosive pigments in highly water‐resistant films. Of course, as the authors point out, all films have a degree of permeability. No doubt this permeability increases as the film ages and, accordingly, the anticorrosive pigment may become more effective as the film ages and loses some of its protective properties.