Swapped my wire brush wheel for a knotted cup on the same job and the difference after 3 days surprised me
I do a lot of pre weld cleanup on tank shells and for years I ran a standard crimped wire wheel on my 4.5 inch grinder. Nothing wrong with it, or so I thought. Two jobs back I picked up a knotted cup brush because the supply guy in Deer Park was out of my usual wheels and I needed something that day. Ran it on a 20 foot seam of 1/4 inch plate, same grinder, same rpm, same operator. After 3 days of using it I noticed I was spending about half the time per foot because the knotted wire digs in and strips mill scale instead of just polishing it. My wrist felt better too, less bouncing. The finish was rougher than the crimped wheel left, which I actually prefer before a root pass. The only downside is it eats itself faster on flat plate, so I still keep a crimped wheel for corners and tight spots. If you are doing heavy scale removal, give the knotted cup a shot before you write it off. What are you all running for pre weld cleanup on thicker plate?
Swapping tools and getting a better result is the same thing that happens when you stop forcing a job with the wrong setup, whether it is a grinder or a lawn mower blade. The knotted cup bites and clears scale while the crimped wheel just smears it around, and that is the whole difference. Try matching the tool to the actual work instead of sticking with the one you always grab.