Rubyfluid Soldering Paste Flux is a petroleum-based general purpose soldering flux with the trademark ruby-red color, a feature that makes the flux visible when applied. Ruby Paste Flux promotes effective solder joints and as a paste form, it helps restrict flux and solder flow to a desired joint area. Ruby Fluid Paste Flux is used in numerous applications, including stained glass, plumbing, roofing, electrical and many others. Recommended Metals – Copper and copper foil, Brass, Tin, Ferrous Metals Works with Tin/Lead, Tin/Silver, and other Tin Alloys Recommended Temperature ranges – 200 – 600°F
