Using Hydrodynamic Testing to Assess the Performance of Five Fouling Control Coatings Immersed at Two Field Sites along the East Coast of Florida

Abstract

Static immersion studies are commonly used to assess the performance of fouling control coatings. While these tests provide valuable data, it is also of importance to understand the drag forces associated with the accrued fouling communities and the velocities required for fouling removal. Combining the measurements of hydrodynamic testing with those from static immersion testing can help in predicting the performance of coatings prior to their consideration for use on Navy vessels. Replicates of five commercially available coatings (three fouling release coatings and two biocide based coatings) were deployed at two static immersion test sites located along the east coast of Florida (Port Canaveral and Sebastian Inlet). After four months of immersion, the panels were removed, photographed, subjected to known water velocities in a high-speed boat modified for hydrodynamic testing. Each panel was run at 5 m/s for 10 minutes, photographed, and then run at 10 m/s for 10 minutes. The drag forces were measured at speeds of 3, 6, 8.8 and 10 m/s for 1 minute each. Photographs taken before, during, and after hydrodynamic testing were also visually analyzed. After testing adhesion measurements were taken to determine the attachment strength of any hard fouling organisms which remained on the panels. The data collected from this series of tests, enabled the fouling control and fouling release properties of each coating to be characterized.