Why should you avoid adding water to colored finish-coat plaster before it hardens?

• A. Because It Causes Color Variations
• B. Because It Slows Curing
• C. Because It Weakens Bond
• D. Because It Increases Shrinkage

Answer: (A)

Introducing water into a colored finish-coat plaster before it hardens disrupts the pigment distribution, which leads to color variations. The pigments are meant to be evenly dispersed, and extra water can dilute or mobilize them, causing lighter, darker, or patchy areas as moisture moves through the surface. Because the goal of a tinted finish is a uniform color, re-wetting during setting compromises that consistency. While moisture can affect curing or bond in other contexts, the most noticeable and direct effect here is the uneven coloring.