Rustfjerning

Rustfjerning, or rust removal, refers to the process of removing iron oxide from metal surfaces to halt corrosion and restore function. It is used on ferrous metals such as steel and iron, as well as cast iron and some alloys. The goal is to remove existing rust, prevent further rusting, and prepare the surface for protection, such as priming and painting or coating.

Common methods include mechanical removal (wire brushing, grinding, sanding, sanding with abrasive discs, sandblasting). Chemical rust removers contain acids such as phosphoric acid, oxalic acid, or citric acid to dissolve rust or convert it to a stable layer (rust converters). Electrochemical rust removal, or electrolysis, uses an electrolyte solution and an applied current to convert rust back to metallic iron and lift oxides from the surface. For delicate or large items, there are less aggressive methods and specialized equipment.

Process typically involves removing loose rust, degreasing the surface, applying the chosen rust removal treatment, rinsing and drying, and applying a protective coating to prevent re-oxidation. After chemical treatment, passivation and drying are important to reduce flash rust. For best results, surface cleanliness and appropriate coating systems are essential; test on a small area when using unfamiliar products.

Safety considerations include handling acids with eye and skin protection, adequate ventilation, and safe disposal of spent solutions. Mechanical methods produce dust or grit; appropriate PPE should be used. The selection of method depends on object size, geometry, accessibility, cost, and desired finish, as some methods are faster but more aggressive, while others are gentler but slower or more expensive.