The Killed Spirits
Contact DetailsSean Kilby
Zinc chloride has the ability to attack metal oxides (MO) to give derivatives of the formula MZnOCl2. This reaction is relevant to the utility of ZnCl2 as a flux for soldering - it dissolves oxide coatings exposing the clean metal surface. Fluxes with ZnCl2 as an active ingredient are sometimes called "Tinner's Fluid." Typically this flux was prepared by dissolving zinc foil in dilute hydrochloric acid until the liquid ceased to evolve hydrogen; for this reason, such flux was once known as KILLED SPIRITS. Because of its corrosive nature, this flux is not suitable for situations where any residue cannot be cleaned away, such as electronic work. This property also leads to its use in the manufacture of magnesia cements for dental fillings and certain mouthwashes as an active ingredient.