The Kester 5560 cleaner is a non-fuming liquid solution for removing oxides, sulfides, carbonates and other contamination, such as etch residues, from copper metal surfaces to facilitate soldering. This stable solution cleans by dissolving or solubilizing the contamination for easy removal by water rinsing. The chemical cleaning action is quite different form strong mineral acids which etch away valuable base metal and passivate the surface by insoluble film formation. 5560 is very effective in cleaning silver-plated surfaces with no appreciable metallic etching. - 5560 contains a pink pH indicator which turns yellow at pH 3.5 indicating the solution has lost its efficiency. 5560 is a non-foaming chemical for use in spray cleaning equipment. Because the etch rate is controlled, the bath life is very extended. 5560 will selectively remove surface contamination from solder-plated or tin-plated surfaces as well as very tarnished copper surfaces.