Metal surfaces must often be cleaned before subsequent operations to remove unwanted substances such as pigmented drawing compounds, unpigmented oil and grease, chips and cutting fluids, polishing and buffing compounds, rust and scale, and miscellaneous contaminants. The article describes common cleaning processes, including alkaline, electrolytic, solvent, emulsion, molten salt bath, ultrasonic and acid cleaning as well as pickling and abrasive blasting. It also explains how to select the appropriate process for a given soil type and surface composition.

Molten salt baths are anhydrous, fused chemical baths used at elevated temperatures for a variety of industrial cleaning applications. This article discusses their applications in paint stripping, polymer removal, casting cleaning, glass removal, and plasma/flame spray removal. It provides an overview of the basic design and safety considerations of the salt bath equipment and describes the environmental impact of molten salt bath cleaning.