Figure 41 . Chemically cleaned aluminum alloy panels; pockets of deep corrosion 

 had formed along the edges and ends of exposed panels (right). Such 

 corrosion was absent from control panels (left). 



Figure 42. Chemically cleaned surfaces of carbon steel (left) and aluminum alloy 

 (right) panels. Steel — Surfaces of both control and exposed panels 

 corroded uniformly. Aluminum — Crevice and pitting corrosion were 

 absent over control (short) panels. Crevice corrosion around bolt holes 

 and trace of pitting corrosion were present over exposed (long) panel. 



48 



