Stay-Silv® Brazing Alloys, Phos/CopperAWS A5. 8 BCuP 5 QQ B 654A The industry standard for air conditioning refrigeration applications. ; ; Typical application: Good ductility; ; Phos copper and silver phos copper alloys are used to braze copper to copper and copper to brass. The phosphorus content in these alloys makes them self fluxing on copper. When brazing brass or copper to brass, use Stay Silv white brazing flux. These alloys are not recommended for brazing steel or other ferrous