Rust Problem does not go away need help

[artooks]

Hi Everyone,


I have a shotgun condenser that I have purchased from SD a few years ago, my main problem with this condenser is that I. see rust spots at the top opening inside the tubes, I have electopassivate it twice cleaned it with BKF, citric acid and etc but even I see it less but still very small rust spots still emerge I do not know what to do at this point, and it really become a big problem, do you think small rust spots is still a problem or is it acceptable, I do not want to see it so what can you recommend what can I do to fix this problem. Should I scrub with the green part of the sponge does it help ?


Thanks



Arto Sevan Oksayan