Rectorseal 83562 Cool Braze 1/2 lb. (6 Pack)Rectorseal 83562 Cool Braze completely stops heat transfer up to 3000F when brazing, soldering, or welding copper or brass. It provides effective protection as a heat shield for TXVs, reversing, and ball valves. Cool Braze blocks direct and conductive heat on surfaces and metals including composite panels, rubber, and plastics. It will also stop the warpage of thin metal due to heat. Features Reusable for life Block direct and conductive heat. Stops