[MOTORHEAD]

It was originally used for sealing acft crankcase halves ( machined aluminum surfaces, no gasket other than one or two lines of thread) on RR acft engines in WWII, when the only other sealer was a shellac type that would dry out and leak. It is still a popular item in present day acft recips and porsche/vw engine builds. Don't know how good it would be in other applications, or if the formulation has been changed since permatex bougght it.
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