BlueDevil Radiator & Block Sealer is designed to be an easy-to-use formula that will repair and seal leaks in radiators and engine blocks. It does not contain solid or fibrous materials, and it will not clog or harm cooling systems, according to the company. This sealer will bond to plastic, cast iron, aluminum, alloy or metal. BlueDevil Radiator & Block Sealer is compatible in gasoline and diesel engines. It serves as a guaranteed permanent repair, says the company.