Castrol Rustilo181 is a dark brown solvent deposited corrosion preventive fluid which, after evaporation of the solvent, gives a hard waxy yet flexible film. Rustilo 181 is a long term protective for use in severe conditions where a high degree of protection is required. It is ideal for protection of to certain engine spares such as fuel injector nozzles, fin tubes and similar highly finished parts prior to long-term storage or transportation. Rustilo 181 used to be applied by immersion, brush or spray.