Submergence Testing of Antifoul Coatings on Additively Manufactured Panels in Coastal Maine

Large format additive manufacturing (LFAM) with reinforced thermoplastics is an emerging technology for marine structural applications such as buoys and watercraft. Marine structures typically require an antifoul coating to mitigate the negative effects of marine life such as algae, tube worms, kelp, sea squirts, barnacles and mussels. In this pilot study, LFAM is used to manufacture a variety of wood fiber reinforced PP and PETG panels with dimensions of approximately 300 mm x 300 mm x 12 mm. As printed (uncoated) and fully coated panels are studied with two commercial varieties of antifoul coating. Steel panels with a military-grade antifoul coating are used as a baseline to gauge the effectiveness of all coatings used on the 3D-printed panels. A reusable floating test panel apparatus is constructed to submerge panels to depths of 0 m to 1.2 m for a full calendar year in a tidal impoundment at the Downeast Institute on Beal’s Island, ME. Qualitative assessment of fouling resistance is completed at 4-month intervals along with identification of prevalent marine organisms. The effects of marine submergence on physical, mechanical, and thermal properties of the 3D-printed panels are presented.