Hercules 1 lb. Boiler Solder (Powdered Stop Leak)

Powdered stop-leak quickly finds and seals trouble spots on cracked steam or hot water heating boilers. Forms a tough seal that expands and contracts with boiler metal. Resists high pressure and temperature. Once set, seal will not be dislodged by boiler cleaners. No odors. Petroleum-free. Will not clog system, valves and vents or interfere with normal boiler operation. Will not harm rubber or plastic parts. Compatible with Hercules cryo-tek or other types of propylene glycol based anti-freeze products, chemical additives and boiler treatment compounds.