#5 PASTE FLUX - The standard by which other fluxes are measured. Cleans and fluxes at the same time. Formulated with a high flash point, and stays in suspension under normal weather conditions and temperatures. Blended to clean surface oxidation and provides superior wetting properties which allow better solder flow. Surrounding metal is coated to help prevent copper from turning green. Effective on all metals except aluminum and stainless steel.