Holiday detection on Painted or Coated Surface
Holiday detection on Painted or Coated Surface A coating must be applied as a continuous film to perform its intended function. Early failure will occur if there is a discontinuity—a holiday, as it is commonly called—such as a pinhole, void, crack, thin spot, foreign inclusion, or contaminant in the coating film. Many of these defects are not readily visible, but they can be located using holiday detection equipment. Discontinuity: A void, crack, thin spot, foreign material inclusion, or contamination in the coating film that significantly lowers the electrical resistance of the coating. May also be identified as a holiday or pinhole. Holiday Defects characterized by a film having areas of insufficient thickness, even to the point where parts of the surface may remain uncoated. Holiday Detector: A device that locates discontinuities in a coating film applied to a conductive substrate. Pinhole The formation of minute hole in the wet film or drying due the burst of gases or...