General Purpose Solder Paste Flux. Designed Primarily For Copper To Copper And Copper To Brass Connections The Paste Form Is Ideal For Soldering Tube Joints. Not Recommended For Electrical Or Electronic Applications Due To The Potential Corrosive Residue Of The Flux. Stay Clean Paste Flux Works Well With Most Leaded And Lead-Free Solder Compositions. Flux Residue Should Be Removed After Soldering.