Copper -Zinc Brazing Alloys are suitable for gas-flame brazing,high temperature drazing of copper and copper alloys,nickel,cast iron and hard alloys.During oxy-acetylene brazing,to heat with oxidized flame quickly  can lessen evaporation of zinc and prevent porosity from over -oxidization.The optimum joint gap is 0.025-0.1mm.Flux is also necessary to obtain good brazing seam.