Arch121 Building Technology: Paints Part 1

Introduction to Paints

• Paint is a coating material applied thinly to a surface to finish, decorate, and protect it.
• Paint is composed of pigments suspended in a liquid vehicle.
• There are multiple types of paints, each with its own distinct properties suitable for a specific use case depending on the surface material.

Typical Components of Paint

• Pigments: A finely grounded substance that provides color and opacity to the paint.
  • Examples of paint pigments: Ocher, Titanium oxide, Iron oxide, Phthalo blue
• Vehicle: Composed of both binder and solvent, in which pigments are mixed to produce paint.
  • Binder: bonds particles together during the drying process.
  • Solvent: catalyzes the drying process by evaporation.

History of Paints

• Prehistoric: Early humans used primitive paint compounds as early as 40,000 years ago to depict human activity and animals.
  • Examples: Lascaux cave (France), Laas Geel cave (Somaliland)
• Ancient Egypt: Early artists used paint pigments such as charcoal black, red ochre, yellow orpiment, and blue azurite.
  • Binders: Egg, resin, and beeswax.
• Ancient Greece and Rome: Greeks used fresco painting technique, while Romans used the dry method of painting called Secco.
• Middle Ages and Renaissance: Egg and Tempra were widely used during the middle ages, while Linseed oil replaced egg as a paint base during the Renaissance.

Types of Paints

• Oil Paint: Uses drying oil as its vehicle, ideal for artistic medium due to its workability and longevity.
• Enamel Paint: Oil (alkyd) based paint with a glossy, hard, water-proof, and fast-drying finish.
• Acrylic Latex Paint: Water-based paint with an emulsion vehicle, ideal for masonry/concrete surfaces and popular as an artistic medium.
• Metallic Paint: Uses two liquid components as a vehicle, with a high-gloss, tough, durable, and water-proof finish.
• Luminescent Paint: Contains fluorescent or phosphorescent pigments, used for specialized applications.
• Intumescent Paint: Used as a passive fire suppression system, coating layers of paint that expand and form an insulating layer when subjected to high temperatures.
• Teflon Paint: Uses a synthetic polymer (PTFE) as its base material, providing a non-stick coating.
• Anticorrosive Paint: An anti-corrosion coating for treating metals that are vulnerable to rusting or oxidation.
• Wood Stain: A type of paint that contains mostly of vehicle with a smaller proportion of pigments and binder, used to manipulate the color of the base material.

Paint System

• A series of layers or coatings applied on the base surface of a material.
• The three layers of the paint system:
  1. Prepared Substrate: Highly dependent on the type of surface material.
  2. Primer: The primary coat of the paint system, improves adhesion and protection of the surface material.
  3. Intermediate Coating: The body of the paint system, hides the color of the base material and further improves the adhesion of the top coat.
  4. Finish/Top Coat: The last paint coat of the system, provides aesthetic appeal and protection of the paint system.

Finishes

• Matte Finish: A non-glossy and non-reflective finish that soaks up light.
• Eggshell Finish: A popular paint finish with a velvety-like appearance, has a minimum sheen.
• Satin Finish: A popular all-around paint finish, known for its durability and middle-of-the-sheen-spectrum finish.
• Semi-Gloss Finish: Has a high degree of shine, good for high-traffic areas and high-moisture areas.
• High-Gloss Finish: Has a high degree of reflectiveness, easy to clean, but can accentuate imperfections.