• Rinse, 2 min at room temperature 



• Rinse in deionized water at room temperature 



• Place three aluminum tube/aluminum fin heat exchangers 

 in individual plastic bags for return to CEL 



• Paint one aluminum tube/aluminum fin heat exchanger with 

 Sherwin Williams R74BC23 POWERCLAD enamel (black) at 

 150V DC maximum, 2000 amp 



• Bake painted heat exchanger; dry film thickness of 

 coating, 0.8 mil (0.0020 cm) 



• Place coated exchanger in plastic bag for return to 

 CEL 



One set of three heat exchangers was coated, by dipping, at CEL as 

 follows : 



• One coat of MIL-P-15328C primer (wash) pretreatment (blue), 

 Formula 117B, for metals 



• One coat of TT-P-645 primer, zinc chromate, alkyd type 

 (edges of fins were dipped twice) 



• One coat of TT-E-489 enamel (black), alkyd, gloss 



One set of three heat exchangers was coated, by dipping, at CEL; 

 the procedures were as follows: 



1. Copper tube/copper fin and copper tube/aluminum fin: 



• Brush sandblast 



• One coat Dimetcote No. 3 zinc inorganic silicate (edges 

 of fins were dipped twice) 



2. Aluminum tube/aluminum fin: 



• One coat of Dimetcote No. 3 (edges of fins were 

 dipped twice) 



A micrometer was used to measure fin and dry film thicknesses. 

 Data on thickness of the coating systems applied at CEL are presented in 

 Tables 1 and 2. 



One set of three heat exchangers was left uncoated. 



All sets of the exchangers were photographed before installation in 

 the exposure facility (Figures 1 through 4) . 



Exposure Facility 



A facility in which to expose the heat exchangers was designed at 

 CEL. Required components were either purchased or were fabricated by 

 CEL. The facility (Figure 5) consists of: 



