The combined use of coatings and CP is an area which has developed significantly during the last decade. The use of coatings and CP has several advantages for offshore structures: The total current demand is reduced, an even current distribution and a fast polarisation of the structure are achieved An uncertain factor with respect to design of CP system and evaluation of cost benefits is the progressive coating deterioration with time. The paper presents data on coating degradation
on catholically polarised painted steel specimens exposed to natural sea water at ambient temperature. Coating degradation is monitored by measuring the current and by determining the rate of cathodic disbanding with time. The results from the sea water tests are compared with results from the tests used to qualify coatings for use on submerged steel structures i.e. ASTM G8: “Standard Test Method for Cathodic Disbanding of Pipeline Coatings” and BS3900 Part F10” Determination of resistance to cathodic disbanding of coatings for use in marine environments”.
Keywords: cathodic protection, Coating quality, Coating breakdown, cathodic disbanding. Asessment of coating performance.