preseasoned pan - now blackened and chipping While I've found similar posts, I have not found a perfect answer and thought I'd share my cleaning routine in case that is creating a problem.  I purchased a pre-seasoned Lodge skillet about a year ago. I also have my Grandmothers old Wagner that looked to be well seasoned as well.
My issue is that the Lodge currently is fairly lumpy on the bottom and food will pick up quite a few black flakes.  I've tried taking a spatula to it to try to pick up some of it and then wiping it, but it doesn't get much of it.  I think when the pan is hot more comes off.
My cleaning routine is this:  After using pan, I boil hot water in it to pick up any of the baked on food.  I "scrape" it as it's boiling with a wooden spatula.  Then dump the hot water and rinse with just plain water wiping it dry with a paper towel.  I then will add a little oil (either grape-seed or regular olive oil) and wipe that around the entire pan with a paper towel.  Then putting the pan back on the hot burner to "cure".   All along I've thought of this as a mini curing session each time I use it which is a lot.  But maybe it's too much somehow?  Or maybe the boiling of the water in it after use is too much?  I can't figure out what I'm doing wrong.  I do the same thing with all of my cast iron pans and I have varying degrees of "not smooth" bottoms.  Including the Wagner.  Please help!  I definitely do not have that baby smooth surface like others speak of.  Thanks in advance!
Try to use vinegar in the hot pan to remove solids of food. Also, adding salt while washing and brushing helps removing that heavy duty dirty.

After that, gently dry the pan in the stove and add oil just after all the water evaporates. Use a paper towel to help evenly spread the oil.

Then put the pan back in the stove or oven in a low fire.

That's what I do.