Clean Hulls Without Poisons: Devising and Testing Nontoxic Marine Coatings

By Robert F. Brady, Jr

Because this paper marks 50 years since the first Mattiello Memorial Lecture, it begins with a remembrance of the man in whose honor we meet and an appreciation of his character and his contributions to the coatings industry. The body of the paper is concerned with the coating used on a hull of a ship to prevent the accumulation of barnacles and other fouling.

The most effective antifouling paint now being used contains toxins and will be forbidden by international regulations within eight years. The ideal replacement will be a nontoxic material that resists the attachment of marine life and encourages the organisms to fall off the ship.

This paper describes laboratory and field work during the past 18 years on a variety of fluorinated coatings and silicone coatings with these properties and criteria for formulating successful nontoxic coatings. Silicone and fluorinated coatings frustrate fouling by different mechanisms, and thus the criteria for a successful coating are distinct in important ways.