Polyurethane Sealant to Mitigate Crack Effects in Glass-to-Metal Sealed Underwater Connectors

Abstract

Glass insulated underwater connectors allow for deep sea exploration. However, the long term reliability of the insulation is reduced due to surface cracks formed during manufacturing. In this thesis, we propose and test a sealant to overcome limitations associated with internal cracks. The need for a sealant was identified following a series of experimental tests simulating environmental, operational, and human handling conditions. Analysis shows there is an insignificant effect of insulation resistance attributed to any undetectable crack growth formed during operational and handling conditions. Seawater intrusion, however, is determined to be the primary failure mode. An extensive cleaning procedure allows for partial recovery from salt damage, although the process is unsuitable for field maintenance. We show promising test results in easing cleaning requirements for a recoverable connector by applying a polyurethane sealant to the connector face.