Manual ironing with steam and dry irons.

The creation of a joint between either the faces of sheet metal components or between wires and terminals using molten solder with a flux. 

The corrosion resistance of iron and steel can be improved by treatment with sulfuric and phosphoric acids. Other metals are also affected through the introduction of chemicals.

The removal of scale from hard water from sinks, taps, toilet bowls, washbasins, baths, kettles and steam irons. All use some form of acid as the active ingredient.