What Does Holiday Mean?
A holiday, in relation to an anticorrosive surface coating, is defined as:
- A discontinuity in coating, when a part of the surface remains uncoated
- A defect such as an area of insufficient coating film thickness
- A pinhole within the coating
- A crack within the coating
- An improper adhesion or bonding of the coating
It is essential to detect and study a holiday in the protective coating and take urgent corrective measures. Otherwise the corrosion process can begin at the undetected holiday and irreversible damage can occur to the material resulting in a possible life-threatening and expensive failure.
A holiday is also known as a jeep.
Corrosionpedia Explains Holiday
Anticorrosive coatings are normally applied on pipes and structures to protect the substrate materials from corrosion. Different types of defects can be generated during application due to both the process and human error. The discontinuity in the coating on the substrate material surface is generally called a holiday. Holidays also include other types of defects such as:
- Lack of bonding
- Cracks in the coating
- Insufficient or excessive film thickness
It is very difficult to detect holidays such as pinholes, discontinuities and improper bonding of protective coatings, as it can’t be done during the inspection unless sophisticated equipment is used. A coating is sometimes applied to a material substrate to reduce abrasive wear of the substrate and occasionally to reduce liquid or gas product reaction with the substrate and contamination of impurities due to erosive wear and chemical reaction. The type of coating continuity required is specified as per designed integrity requirement and requirements of environment conditions. Holidays in a coating could be very minute and not readily detected. Precision electrical measurements ensure the detection of pinholes, cracks and bonding defects.