How must a surface be evaluated and prepared before applying a granular compound?

How must a surface be evaluated and prepared before applying a granular compound?

• A. It must be clean, as straight as possible, with precise masking of adjacent surfaces
• B. It should be rough and irregular for better adhesion
• C. No preparation is needed
• D. Only moisture level matters

Answer: (B)

Creating a good bond for a granular compound starts with giving the surface something to grab onto. A rough and irregular surface provides mechanical interlock and more contact area, which helps the granular material adhere as it sets. Before applying, evaluate and prepare by removing dust, oils, and release agents, and ensure the substrate is sound and dry. If the surface is glossy or smooth, lightly abrade it to create a keyed texture. Moisture must be controlled, but it isn’t the only factor—without a proper key and clean surface, adhesion will fail regardless of moisture. While protecting nearby areas is part of prep, the crucial step is achieving the right texture and cleanliness to support bonding.

Creating a good bond for a granular compound starts with giving the surface something to grab onto. A rough and irregular surface provides mechanical interlock and more contact area, which helps the granular material adhere as it sets. Before applying, evaluate and prepare by removing dust, oils, and release agents, and ensure the substrate is sound and dry. If the surface is glossy or smooth, lightly abrade it to create a keyed texture. Moisture must be controlled, but it isn’t the only factor—without a proper key and clean surface, adhesion will fail regardless of moisture. While protecting nearby areas is part of prep, the crucial step is achieving the right texture and cleanliness to support bonding.