Marvelux is non-corrosive to iron and steel, and does not produce fumes, which can cause corrosion, as does sal ammoniac (ammonium chloride). In fact, regular use will keep your pot free from rust! Reduces dross formation dramatically while increasing fluidity of bullet alloys, making it easier to obtain well filled-out bullets. Well suited to any lead alloy melt intended for casting bullets or swaging cores. Non-smoking, flameless and non-smelling. Superior to beeswax, tallow, paraffin, and other grease-type fluxes.