It is generally accepted that the performance of a coating system is improved by good surface preparation before application. For temporary protectives the requirements are less onerous and will depend on the component being protected and its surface condition. In general surfaces must be free from contaminants that are corrosive, or may impair adhesion or continuity of coating, or restrict access of inhibiting vapours. The contaminant will normally dictate the choice of preparation. Solvent degreasing, an alkali wash or steam cleaning would remove oil or grease for example and mechanical, acid and electrolytic techniques may be employed to remove scale or rust. In some cases a simple water wash may be sufficient but others may require a combination of more than one treatment.