Loctite 5188 is a highly flexible sealant which cures when confined in the absence of air between close-fitting metal surfaces. It is designed for use on rigid metal flanged connections, particularly where minor oil contamination of the flange surfaces can occur. The product is particularly suitable for use on aluminium substrates where very good adhesion is needed. It ensures an instant, low-pressure seal. For sealing rigid flange faces on transmissions and engine casings.