Painting vs Coating / Difference between Painting and Coating
Due to no clear definition for any term in the regulations and standards, the names are frequently used interchangeably. The term “painting specification” has traditionally been applied to industrial applications.
However, many end-users are currently altering the title of their specification to “Protective Coating Specification” or “Painting (Coating) Specification” because industrial needs are based on one or more of the following purposes:
- Functional performance
- Decoration/aesthetics
- Color-coding (safety base)
Example 1: Oxygen Cylinders are painted black in color (color code standards – IS 4379) also provides basic protection from atmospheric corrosion
Example 2: Anodising of Aluminium or Titanium, is a coating whose main function is corrosion resistance.
| Description | Coating | Painting |
| Meaning | Coating is umbrella term (general) for any applying a material layer on the substrate. | Painting is one type of coating process (usually polymer or slurry based) |
| Purpose | Performance focused | Decorative or aesthetic focus with some protection |
| Applying method | painting, chemical or physical deposition, electro-chemical plating | Mainly brush, spray, sponge roller. |
| Type of bonding | Physical or Chemical | Mainly Physical |
| Commercially Known Processes/ Products | Conversion Coatings Phosphating Anodizing CVD – to learn click here PVD Thermal Spraying/Cold Spraying | Wall, Wood Paints Varnishes Metallic Paints on furniture |
| Application | Other than anticorrosion paints also used for functional purposes, such as mechanical protection coatings, fire protection coatings, waterproofing coatings, wear-resistant coatings, which can be applied on metals, concrete, and other substrates. | More often used for decoration or color coding rather than the functional purpose. Many people use “painting” to cover everything. In the material terms, all paints are coatings but not all coatings are paints. |
| Materials that can be deposited | Any solid or liquid film to a substrate or to the application of such a layer on the substrate material. | A layer on the substrate with paint, varnish, lacquer, tar, etc. in liquid form or to the application of such a layer. |
| Thickness of the film | Used for lower and also higher thicknesses. | Used for lower thicknesses. |
In terms of the material point of view, all paints are coatings but not all coatings are paints.
Coating vs Painting / Difference between Painting and Coating
References
- Jung-Chul (Thomas) Eun, “Handbook of Engineering Practice of Materials and Corrosion”, Springer 2020