KwikFlux Silver Brazing Flux 12oz. KwikFlux Silver Brazing Flux is a hard soldering Flux, specifically designed for harder metals such as Silver, Gold, Copper, Nickel, and Platinum. It comes in a creamy paste form and is easily applied using the handy squeeze bottle. Contains: 12 Fluid Ounces Bottle size: 7" x 2" Material: Paste Flux Country of origin: USA