Cleaning aluminum slots

i think the wheels must have set out side for a very long time.The acid did make them look better,but they were so badly corroded,that i was about to go at them with 80 grit on my da sander to start with,but i decided to try 180 first,and it did pretty good,but still was a lot of work,it took 16 hours to make the wheels look like they do in the pics