So I'm hoping someone can help with an ongoing issue I'm having with my cast-iron skillet. I have a 12" Lodge Logic skillet that is in absolutely beautiful condition, but my 6.5" skillet, which I treat in a basically identical manner, has bumps all over the inside wall of the skillet. I've scrubbed it out before, but it has reappeared. Any idea what can be causing these? It's not really affecting the performance of the pan, but it is pretty unsightly, not to mention when I wipe the skillet with a paper towel it gets a little chewed up and leaves pieces of paper stuck to the inside.
Just as an FYI, my usual maintenance routine is cook, wipe the pan out immediately, eat my dinner, then rinse out, scrub away anything stuck on with kosher salt if necessary, put the pan back on the heat and wipe with a thin layer of vegetable oil when it's screaming hot again.