Term: saponification

Saponification is a chemical reaction that occurs when a fat or oil (which are triglycerides) reacts with an alkali (commonly sodium hydroxide or potassium hydroxide). This reaction produces soap and glycerol (glycerin).

In simple terms, it's the process used to make soap.

Chemical equation (simplified):
Fat/Oil (Triglyceride) + Alkali (NaOH or KOH) → Soap + Glycerol

In the context of painting and coatings (especially relevant to painters and contractors), saponification can also refer to a detrimental reaction that occurs when alkaline substances (like fresh concrete or cement-based surfaces) come into contact with oil-based or alkyd paints. The alkali can break down the paint, leading to:

• Softening or breakdown of the paint film
• Loss of adhesion
• Blistering or peeling

Tip for painters: Always check the pH of masonry or concrete surfaces before applying oil-based coatings, and use appropriate primers or sealers to prevent saponification.