Improving the Chemical and Physical Properties of Plasma Sprayed Non-conductive Ceramic Coatings

Cathodic Delamination is an unavoidable phenomena that is a major contributor to the premature failure of any submerged outboard cable connector that is attached to a cathodically protected structure, usually a vessels hull. The most prevalent strategy used to slow down this process is by coating cable connectors in plasma sprayed non-conductive ceramic. This technique has not been examined/altered in over 30 years and it can be improved upon by making material and procedural changes. The research in this paper focuses on finding a high pH resistant replacement ceramic layer sealant as well as trying to reduce the porosity of the plasma sprayed ceramic layer. Achieving even one of these should greatly increase cable connector longevity. It is part of an overall effort to increase the effectiveness of plasma sprayed ceramics ability to resist Cathodic Delamination. Metco ERS, an epoxy based sealant was found to be superior seal coat to the more commonly used phenolic based sealcoats. Attempts to control the porosity of the ceramic layer were unsuccessful. This research is ongoing.