Small size blisters and vacuoles in industrial paint films, which are induced by corrosion or insufficient curing, can not be observed by simple means. A holographic method is presented which visualises small deformations of the paint surface, on the places of these defects, after lowering the pressure over the paint film. In experiments with Alkyd-Satin paint films, with a thickness between 0.03 - 0.18 mm, appplied on a Washprimer, blisters with diameters between 0.1 - 1 mm were detected after a maximum of 24 hours of vacuum-stressing.
|