I wouldn't bother with all that. I'd recommend finding an antique cast iron pan (local thrift store, flea markets, Etsy, or eBay) and restoring it (there are services for this or you can do it yourself fairly easy) and using that. The antique pans are just way better.
Or you can try carbon steel which is more forgiving than cast iron. Blanc Creatives makes a great carbon steel pan/skillet.
I was not able to find an antique pan for less than the price of a modern pan and angle grinder. So I recouped my tool investment on the first pan alone.
That guy is not wearing a face mask or proper eye protection. You don't want to make a habit of inhaling iron filings.
Do it in a well ventilated area, preferable outside. The fillings get everywhere, include into any vents of any other equipment you might have nearby. My glasses weren't enough to keep the filings out of my eyes. They are fine enough that they won't scratch or cut your eyes, but you will feel like you are having the worst bout of seasonal allergies you've ever had.
Have you ever in your life tried to use an angle grinder for this sort of thing? It’s one of a family of cutting tools built on the Ouija board principle. It transforms human energy into a crooked, unpredictable motion, and the more you attempt to influence its course, the more dismal your future becomes.
If i had a cast iron pan I had to flatten, I’d dog it down on my CNC router, set up a 1/4” endmill, whip up some code for 33% overlapping passes in Fusion 360, and take off .005” layers until it was flat.
Probably, random orbital sander would do the trick, but slower and chew through a lot of sanding discs. It took me years to finally acquire a grinder - just no real need between sanders and saws. Once I started working on concrete and metal it became necessary, and now it seems like a luxury for all the little things which I probably should have been enjoying a long time ago. But IME, most people under 40 don’t have an angle grinder laying about. So borrow one from a 40+ friend before making the ROS do the work, IMO.
