Typically, coatings have not been used in the submerged areas of offshore steel structures because of a lack of confidence in their ability to perform in conjunction with cathodic protection. With short life expectancy, they appeared too costly. Attempts to cathodically protect bare steel structures have not been completely successful because of excessive current requirements, shielding problems, limitations of anode throwing power, and weight. Since 1975, an experimental program has been conducted by Ameron to evaluate the performance of coatings both with and without cathodic protection in simulated marine exposure. Numerous marine coating systems have been tested over a 5-year period using protection levels of -850, -1100 and -1200 mv to Cu/CuSO sub 4 electrode. The tests are described and results are presented and discussed. The results indicate that certain coatings are compatible with cathodic protection, with 2 specific systems offering relative insensitivity to long-term overvoltages of -1200 mv (Cu/CuSO sub 4 electrode). Lower protective current densities required for coated steel coupled with more uniform protection offer potential benefits. The design of a cathodic protection system can be simplified and the systems efficiency improved by using the long-term compatibility data developed in this program. Problems associated with cathodic protection of offshore steel structures can be reduced by use of coatings for the submerged portion.

Media Info

  • Features: References;
  • Pagination: p. 9-26

Subject/Index Terms

Filing Info

  • Accession Number: 00329921
  • Record Type: Publication
  • Report/Paper Numbers: Volume 4 Proceeding
  • Files: TRIS
  • Created Date: Apr 15 1981 12:00AM