Tackle Paint, Oxide & Weld Splatter Cleanup with Norton Wire Brushes

[@firstmkb]

I'm removing a lot of rust from a 30 year old boat trailer and a steel (or cast iron) keel, prior to welding repair and painting. I'm currently using and angle grinder with cheap brushes (not good Norton ones), and they shed bits of wire at high speed. The frame has C-shaped structural steel, some bolts I can't remove, 90 degree inside corners, and some tighter near the tongue of the trailer. Are Norton cup brushes designed primarily for flat surfaces? Are the end brushes for inside corners, or what are the other use cases? When are abrasive wheels a better choice than wire brushes for rust removal / surface prep? What other Norton products would you recommend? Are there any other questions I should be asking? Thanks