Holiday – Pinhole Detection
CSI supplies testing equipment to detect failures that will lead to premature corrosion of a substrate. A major cause is the presence of flaws in the finished coating.
Collectively referred to as porosity, the main types of flaws are:
- Runs & Sags: Coatings move under gravity leaving a thin dry film.
- Cissing: When a coating does not re-flow to cover the voids generated by air bubbles being released from the surface of a coating.
- Cratering: If the substrate is wet or the coating has poor flow characteristics, voids are created in the coating.
- Pinholes: Caused by air entrapment which is then released from the surface, or by the entrapment of particulates (dust, sand, etc.) which do not stay in place.
- Over Coating: If too much coating is applied, internal stresses of the coating can cause it to crack as it cures.