Causes and Effects of Coating Failure
Protective coatings are used extensively in many industries and workplaces for the purpose of safeguarding its assets from catastrophic failures and elements of the environment. Deterioration of these coatings is caused primarily by premature coating failure. Such failures can take place when the bond between the coating and the substrate reduces over time or disappears completely. This leads to a scenario where the surface gets exposed to different elements as the coating is no longer able to perform its function. The most common forms of coating failure include chalking, erosion, blistering, undercutting, orange peeling, and pin-holing.
Before discussing the consequences of coating failure, let us take a look at some common factors responsible for coating failures.
- Surface Preparation: Proper surface preparation is essential for creating a strong bonding between the substrate and the coating. This bonding may be weak or may not take place at all, if the surface preparation is inadequate. This error may lead to a wide array of defects and failures including cratering, blistering, detaching, crawling, orange peeling, improper wetting, and uneven gloss.
- Application Environment: Coating failures can also be the result of different environmental factors during the application of the coating. Variations in temperature, humidity, cleanliness, and air purity often leads to uneven spreading and reduced strength of the bond. Failures caused by application environment related issues include solvent popping, blistering, cratering, etc.
- Application Technique: This is yet another factor that determines the quality of coating. Most of the liquid formulas are applied by brushing, spraying, dipping, or rolling. Each of these application methods requires specific equipment and techniques. If the application methodology is inadequate or improper, failures such as sagging, orange peeling, or running may take place.
- Formulation: The formulation of a coating should be tailored to the end-use environment of the product and its manufacturing process. Improperly formulated coatings are extremely likely to fail, even if there is nothing wrong with surface preparation, application techniques, and application environment. Some examples of formulation related failures include erosion, cracking, chalking, alligatoring, mud-cracking, etc.
The primary goal of protective coatings is to prevent the corrosion of public infrastructures such as highways, bridges, and amusement parks, as well as different utility structures such as storage tanks, pipeline structures, etc. Damage to any of these structures is extremely likely to jeopardize public safety.
Structures damaged by corrosion also pose several other risks as summarized below.
- Reduced structural integrity
- Leakage of toxic fluids and gases
- Contamination of food and beverage products due to corroded metal parts
- Failure of equipment and structures in industries.
In addition to safety, coating failure also has a serious cost consequence. Compared to the initial surface protection cost against corrosion, the cost of repairing and repainting is significantly higher. The cost of installing surface coatings is generally outweighed by the extended service life of the system.
Some major cost consequences of coating failure include
- Repairing and repainting
- Frequent downtimes
- Material and labour cost
- Expenses resulting from potential lawsuits
To find out more about coatings and corrosion control, please contact our experts at Coating Management Solutions.