You need to sand blast the pitted areas very good, and even drill the pits out. THen rinse off and dip the part in pickle #3 for 1 minute until it turns black, ONLY 1 MINUTE, then rinse and blast it again and then flash copper for about 15 min. then do your solder. Then sand down the solder and then flash copper, and then build up in the acid copper for about 2 hrs. I would flash copper for about 30 min to see if it will blister. Good luck and be patient.....
