Abstract: The instant flux and paste containing same are for brazing aluminum material. The flux consists essentially of a particulate blend of aluminum fluoride, potassium fluoride, and cesium chloride, or rubidium chloride or a mixture of cesium chloride and rubidium chloride, the fluorides being complexed with each other or not complexed or being a mixture of the complexed and not complexed fluorides. Lithium fluoride, preferably complexed with the other fluorides, is an optional ingredient. The weight fraction of the total fluorides is between about 1/10 and about 9/10, and the A1F.sub.3 -KF weight ratio is between about 4:1 to about 0.4:1.

Abstract: A single component brazing paste suitable for brazing aluminum and having excellent shelf-life consists essentially of a mixture of (A) from 7 to 35, preferably at least 10, weight percent of a non-aqueous substantially inert vehicle which has a viscosity at room temperature in the range of 30,000 to 100,000 centipoises and which at brazing temperature is capable of volatilization and/or decomposition without leaving a residue, (B) from 18 to 75, preferably at least 25, weight percent of certain brazing fluxes suitable for use in brazing aluminum and containing no metals in free or combined form having a more negative or less positive oxidation potential than aluminum, (A) and (B) when mixed together having a viscosity at room temperature greater than the viscosity of (A) alone and in the range of 80,000 to 250,000 centipoises, and (C) from 15 to 75 percent weight of a particulate aluminum base alloy filler metal such that the mixture of (A), (B) and (C) has a viscosity at room temperature in the range of 200