Table 5. Continued 



Test Panel 



TFE Films 

 (glass-fiber and skived) 



Saran Film 



No Film 



Remarks 



K-Monel 



The TFE films were found adhering to 

 the surface of the entire panel. When 

 the plastic film was removed, the metal 

 surface was very bright and free of 

 corrosion and fouling growth. There 

 were streaks of dark discoloration over 

 the metal where seawater had leaked 

 through the plastic film at the overlap 

 (Figure 7). The TFE films covered 

 with marine growth, including barnacles, 

 could be peeled off the test panel 

 without much effort. 



Saran film was not placed over 

 K-Monel panels. 



The entire surface of the control 

 panel was covered with pits 

 (Figure 7). There were also pits 

 surrounding the base of the 

 barnacle growths (Figure 10). 



TFE films gave complete protection 

 from corrosion and fouling for 

 8.5 months of exposure. 



Stainless steel 



The TFE films were found adhering to 

 the surface of the panels. When the 

 plastic films were removed from the 

 panels, the underlying surfaces of the 

 stainless steel panels were very clean and 

 bright (Figure 9). There was only minute 

 weight loss. There was some crevice 

 corrosion present on the surface of the 

 metal where seawater had penetrated the 

 plastic film through punctures (Figure 11). 

 Elongated tunnel pits present in control 

 panels were not present on TFE-covered 

 panels. 



The saran film was found adhering 

 well to the surface of the stainless 

 steel except along the edges of the 

 panel The edges of the panel 

 were affected by crevice corrosion 

 due to penetration of seawater 

 through ruptures in the plastic 

 film. The saran film covering 

 could be removed fairly rapidly 

 from the panel without the 

 plastic being torn into very small 

 pieces. The underlying surface 

 of the panel was very bright and 

 clean (Figures 12, 13, and 14). 



The control panel was severely 

 marked with several tunnel pits 

 (Figure 15) and crevice corrosion 

 underneath the barnacle shells 

 (Figure 16). 



The crevice corrosion found on stainless 

 steel (type 302) under barnacles and 

 under the plastic films resulted from 

 oxygen concentration cells. As shown 

 in F igure 9, the original writings under 

 plastic covering are visible. 



