Prior to spray painting hot-rolled mill-finish steel, the metal should undergo what preparation process?

Prior to spray painting hot-rolled mill-finish steel, the metal should undergo what preparation process?

• A. It should be sandblasted first to remove rust from mill
• B. It should be cleaned with water and soap
• C. It should be heated to dry
• D. It should be painted directly

Answer: (A)

Surface preparation is needed to ensure the coating adheres properly. Sandblasting hot-rolled mill-finish steel removes rust, mill scale, and other contaminants and creates a clean, roughened surface with an anchor pattern that the paint can grip. This dramatically improves adhesion, film formation, and long-term durability of the spray coating. Cleaning with water and soap can’t remove the tougher oxide scale, heating to dry doesn’t address adhesion, and painting directly onto unprepared steel will lead to poor adhesion and coating failure.

Surface preparation is needed to ensure the coating adheres properly. Sandblasting hot-rolled mill-finish steel removes rust, mill scale, and other contaminants and creates a clean, roughened surface with an anchor pattern that the paint can grip. This dramatically improves adhesion, film formation, and long-term durability of the spray coating. Cleaning with water and soap can’t remove the tougher oxide scale, heating to dry doesn’t address adhesion, and painting directly onto unprepared steel will lead to poor adhesion and coating failure.