Harris® Bridgit® Paste Flux comes in a 4 oz Pay Of Pack and is ideal for use with lead-free solders. Solder flux paste is active at 800 deg F and works well with Bridgit lead-free solder in potable water systems. It will not burn at soldering temperature and aids to minimize black carbon formations that can result in voids as well as leaks. Plumbing paste flux formulated to withstand higher soldering temperatures.