Lecture 9 Coatings and Paints

Paints

A solution of a pigment in water, oil, or organic solvent, used for covering wood or metal articles for protection or appearance.

Coatings

Materials applied to surfaces for protection or decoration.

Pigment

Gives paint color and affects its consistency, application, drying, durability, and hardness.

Binder

Component that helps paint retain its structure and bind it to the surface.

Solvent

Substance that dissolves paint to make it usable at room temperature.

Primers

Basecoats improving adhesion of subsequent coats of paint or varnish.

Sealers

Basecoats reducing absorption of subsequent coats of paint or varnish.

Stains

Solutions of dye or pigment in a vehicle, used to color wood surfaces.

Varnish

Liquid preparation of resin dissolved in oil or alcohol, forming a hard, transparent coating.

Lacquer

Synthetic coatings of nitrocellulose or cellulose derivative dissolved in a solvent, forming a glossy film.

Blisters

Undesirable raised areas on a painted surface caused by various factors like moisture, poor surface preparation, or using incompatible paint types.

Sticking

Undesirable adhesion between two painted surfaces leading to them sticking together, such as a door sticking to the door frame.

Lapping

The appearance of denser color or increased gloss where wet and dry layers overlap during paint application.

Mildew

Black, grey, or brown spots on painted surfaces caused by fungal growth, often due to damp environments or poor quality paint.

Mud Cracking

Deep, irregular cracks resembling dried mud in a paint film, caused by applying paint too thickly or allowing buildup in corners.

Sagging

Downward drooping movement of the paint film immediately after application, resulting in an uneven coating.

Surfactant Leaching

Concentration of water-soluble ingredients on the surface of latex paint, typically seen in high humidity areas as tan or brown spots.

Wrinkling

A rough, crinkled paint surface caused by uncured paint forming a skin due to various factors like excessive thickness or high humidity levels.

Poor Print Resistance

The tendency of a paint film to take on the imprint of an object placed on it, such as shelves, tables, or countertops.

Alligatoring

Patterned cracking in the surface of a paint film resembling the scales of an alligator.

Chalking

Formation of fine powder on the surface of a paint film during weathering, leading to color fading.

Dirt Pickup

Accumulation of dirt, dust particles, or debris on a paint film, resembling mildew.

Efflorescence

Crusty white salt deposits on the surface, leached from mortar or masonry due to water passing through.

Frosting

A white, salt-like substance on the paint surface, less noticeable on white or light-colored paints, often mistaken for efflorescence.

Paint Incompatibility

Loss of adhesion when water-based latex paint is applied over multiple old coats of alkyd or oil-based paint.

Peeling

Loss of paint due to poor adhesion, involving one or multiple coats of paint.

Poor Alkali Resistance

Lack of resistance of a paint film on fresh masonry to alkali and overall deterioration.

Poor Galvanized Metal Adhesion

Paint losing adhesion to a galvanized metal substrate due to improper surface preparation or lack of primer application.

Gloss Retention

The ability of a paint film to maintain its luster over time without excessive or rapid loss.

Paint Defects

Imperfections or issues that arise in the application or performance of paint, affecting its appearance or durability.

Vinyl Siding Warp

Warping or buckling of vinyl siding panels that have been repainted, leading to a distorted appearance.