Loctite 518 gasket maker is a non-corrosive, anaerobic sealer designed primarily for use on aluminum, iron, and steel flanged mating surfaces. It's ideal for on-the-spot emergency repairs, or when a conventional gasket is out-of-stock. The 518 gasket anaerobic gasket maker fills gaps of up to 0. 050 in. and forms a flexible, solvent-resistant seal that will not tear or decay. Parts will disassemble easily even after extended service, and old gasket material can be removed with a putty knife.