made in other bases than vinyl, with chlorinated rubber being the most 

 common. These paints must be used over primers recommended by the manufac- 

 turer. 



Another recommended cuprous oxide paint is Navy polyisobutylene anti- 

 fouling paint, Formula 134, Military Specification MIL-P-22299 . ^■'- This is 

 a specialty paint which is highly flexible and performs well over rubber 

 surfaces. It also can be used on rigid surfaces, although the standard 

 vinyl paint would be slightly better. Cuprous oxide paints with other 

 added antifoulants, such as tributylin fluoride, are common in proprietary 

 products. These additions make the paint more toxic and, therefore, more 

 effective to a wider range of fouling organisms. However, precautions 

 required during its application result in increased costs. 



Organotin Coatings . Two types of organotin coatings are recommended: Navy 

 proposed Formula 170 (DTNSRDC Formula 1020A) and antifouling rubber sheet- 

 ing, such as B.F. Goodrich Company's No-Foul sheet. Formula 1020A contains 

 TBTO and TBTF physically combined in a vinyl base. It is a single package 

 paint which can be rolled, brushed, or sprayed. Its toxicity is not high, 

 but safety measures must be observed in its application, removal, and 

 disposal." -^^ The raw materials are readily available; the composition 

 can be made by any marine paint manufacturer, and it can be stored. Propri- 

 etary organotin paints are also available, although most proprietary paints 

 contain both tin and copper. "^ Some of these perform as satisfactorily as 

 Navy paints. For OTEC use, an organotin paint should be specified for use 

 over aluminum parts. Proprietary paints containing copper or any other 

 materials corrosive to aluminum should not be used. 



The second organotin coating recommended is an antifouling rubber 



TM 

 sheeting called No-Foul . It is 0.080 in, thick and is used as a cemented 



covering over underwater bodies to prevent fouling. The initial cost is 



high, and it requires significant labor to fit the material to the shape of 



the area to be covered. First an adhesive is sprayed on the substrate in 



substrate in several coats, then the back of the rubber sheet also is 



TM 



B.F. Goodrich Rubber Company. 



35 



