Coating
Description
A protective or decorative layer placed on the surface of another material (substrate). The purpose of applying the coating may be decorative, functional, or both. Coatings may be applied as liquids, gases or solids e.g. powder coatings. Examples of the types of materials are used for coatings include:
- Fabrics, Metals, Paints, Varnishes and Polymer films.
The primary purpose for most coatings is protection. Often coatings are used to achieve multiple goals. For example, coatings can be formulated to:
- seal a surface, form a barrier, change color, produce or minimize texture, maintain surface appearance, be anti-corrosive, be anti-reflective, decrease friction, increase wearability, minimize light transmission, provide adhesion, prevent adhesion (non-stick), provide flame resistance, and to provide identification.
A major consideration for most coating processes is controlling coating thickness. Methods of achieving this range from a simple brush to expensive precision machinery.
- Application processes include: draping, brushing, rolling, dipping, spraying, baking, shrink-wrapping, vapor deposition, electrostatic deposition, plating, anodizing, printing.
Synonyms and Related Terms
coat; surface coat; Anstrich (Deut.); enduit (Fr.); revêtement (Fr.); recubrimiento (Esp.); rivestimento (It.); revestimento (Port.)
Collection Risks
(from Tetreault 2017) "Coatings formed by oxidative polymerization, such as oil-based paints, oil-based urethanes, alkyds, melamine and epoxy esters (one-component or one-part systems), should be avoided in museums because they release acids and peroxides that can harm objects, especially papers, metal objects (lead, copper and their alloys) and black and white photographs. Fortunately, with new volatile organic compound (VOC) regulations in Canada and the United States, these coatings are becoming less and less available. The coatings that are generally acceptable in archival and museum contexts are acrylic or acrylic-urethane emulsion paints (latex) and, for special applications, two-part epoxy and two-part urethane paints."
Resources and Citations
- Jean Tetreault, Products Used in Preventive Conservation CCI, December 2017. Link
- Wikipedia: Coating Accessed Oct 2024
- Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
- ASTM, "Standard Terminology Relating to Paint, Varnish, Lacquer and Related Products", Annual Book of ASTM Standards, Section 6, Paints, Related Coatings and Aromatics, ASTM, D16, 7-Jan, Jul-96
- Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997
- The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998
- Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000