SW-HB1 - Hot Block Heat Absorption Putty - 1 lbSolderWeld SW HB1 Hot Block Heat Absorption Putty 1 lb As a non toxic, heat absorbing putty, Hot Block will block direct and conductive heat transfer on all types of surfaces and metals, including joints, valves, fittings, composite panels, rubber, and plastics. Stops all transfer of heat down 3000 degrees F in half an inch. Wrap it around copper, aluminum, and steel pipes! Features A must have when brazing, soldering, or welding! Perfect for stopping