Oatey’s Hercules Sludgehammer Universal Corrosion Inhibitor protects against corrosion and lime-scale buildup. Suitable for all metals including aluminum, cast iron and stainless steel, it helps maintain heating system efficiency. Use corrosion inhibitor along with Cryo-Tek antifreeze when installing new or replacement hydronic heating systems to prevent the build-up of scale and keep the system running efficiently. It is a 96% PG and water blend, has a lower freeze point and higher boiling point than water and is non-flammable, odorless, non-toxic, nonirritating and compatible with Hercules boiler stop leaks and heating system cleaner products. Use Sludgehammer System Restorer and Noise Reducer for older systems or when a new boiler is fitted to an existing system that has sludge and scale build-up.