Black residue on cast iron skillet
HOpe you can help.
I got a cast iron skillet at the thrift store. It's used but clean. When I tried to oil it for re-seasoning, the towel picked up lots of black residue although the pan looks clean. The pan was made in Taiwan and has concentric rings on the inside bottom.
I tried heating the pan, cooling it and then using a brush followed by putting coarse salt in it and wiping hard with an oily paper towel.
Twice. The pan still releases the black smudgy stuff on the paper towel. IS the pan defective? Am I too impatient? Is it safe to use?
Any help/suggestions gratefully received!