So my wife left our cast iron skillet on the electric stove top on high for about 15 or 20 minutes and turned the center of the skillet white. I've went through and scrubbed it all down and oiled it for a re-season and put it in the oven. I've done the oil down and oven a couple of times and the white spot just doesn't seem to get any better. It doesn't seem to take the oil. Is it possible it got to hot there and won't take a seasoning?