failure was noted. The yellow paint used to letter the main column and 

 buoyancy sphere remained intact, even after fresh water rinsing. No 

 significant paint failures or attack was noted on the cable conduit on 

 this section of the tower. No additional rust bleeding from the sealant 

 used on the conduit attachment fasteners was noted. 



About \0% of the sphere was covered with blisters before rinsing. 

 About half of these blisters ruptured upon rinsing and exposed the under- 

 lying primer. The rust at the areas of paint failures noted in the 

 previous Inspections was now loose and flaky. The pit noted in the first 

 inspection (as shown in Figure 4) was accurately measured and found to be 

 a maximum of 0.110" deep. No other significant corrosion was noted. The 

 coating on the joint between the sphere and the steering carriage was 

 blistered and these blisters ruptured upon being rinsed. No corrosion 

 under the ruptured blisters was noted. The rust staining at the faying 

 surfaces of the joint remained after rinsing. The coating on the steering 

 carriage was now moderately blistered as shown in Figure 5. However, no 

 rust staining of the primer underneath these blisters was noted when the 

 blisters ruptured upon rinsing. The rusting at the carriage stop housing 

 flanges was now loose and flaky. Loose flaky rust around one fastener on 

 the flange was noted and is shown in Figure 6. The altitude indicator, 

 as shown in Figure 7, was readable even with the loss of a significant 

 amount of paint coating. The aluminum alloy keys and jacks used to secure 

 the steering carriage were covered with a thin superficial film of corrosion 

 products, as shown In Figure 8. Attack of these areas was superficial and 

 was essentially arrested after the tower was removed from the water. 



The gas generator support structure, as shown in Figure 9, had loose 

 flaky red rust at the edges of the metal frame members. Only superficial 

 corrosion was found associated with this rusting. The titanium cathode 

 on the electrolytic generator, as shown in Figure 10, was unattacked. 

 The platinum anode was also unattacked. The remaining fouling on the 

 platinum anode was easily removed by fresh water rinsing. 



Figures II through 14 show the results of inspection of a typical 

 rusted area on the middle frequency antenna. Figure II shows the area 

 covered with a loose flaky red rust deposit. Figure 12 shows the area 

 after removal of the deposit. Figure 13 shows the defects in the coating 

 which resulted in the attack. Figure 14 shows the area after removing 

 the coating. Note the feathered edge of the coating in Figure 14. Only 

 three coats of paint are present. A red primer, white second coat and 

 gray topcoat. No zinc rich primer was used on this or any other rusted 

 areas of the compliant tubes. Brushmarks In the coatings at the rusted 

 areas indicated that the coatings had been "touched up" at these locations 

 without using the zinc rich primer. Removal of the upper coats of paint 

 In an unattacked area of the low frequency antenna showed that the zinc 

 rich primer was present. 



