Holiday (coating defect)

The thickness of a coating measured after it has dried or cured, usually specified per coat and for the complete system. It is a key quality control parameter, checked non-destructively on metal substrates with magnetic induction or eddy current gauges.

A coating defect in which local loss of adhesion produces dome shaped, fluid filled or hollow raised areas in the film. Common causes include osmotic attraction of water to soluble salts trapped under the coating, retained solvent and application over contaminated surfaces.

A thermosetting epoxy powder coating applied electrostatically to preheated steel, on which it melts, flows and cures to form a continuous film. It is a standard factory applied coating for buried and subsea pipelines and for corrosion protected reinforcing bar.

An additional coat of paint applied by brush or roller to welds, edges, corners, bolt heads and other irregular details where sprayed coatings tend to pull thin. Stripe coating is standard practice in high performance protective coating specifications.