What process uses high-pressure water effectively to prepare a surface for coating?

Waterjetting is the correct answer because it involves the use of high-pressure water to effectively remove contaminants, old coatings, and rust from surfaces prior to applying a new coating. This process is particularly beneficial for delicate surfaces that could be damaged by abrasive methods like sandblasting. Waterjetting uses focused streams of water to clean surfaces without the use of chemicals, making it an environmentally friendly option.

In contrast, sandblasting uses abrasive materials to mechanically remove old coatings and debris, which may not be suitable for all surfaces. Pressure washing, while similar, typically utilizes lower pressures and is often employed for general cleaning rather than surface preparation for coatings. Steam cleaning uses hot steam for cleaning but does not reach the high pressures necessary for effective surface preparation as required in many coating applications.