seasoning won't stick to areas of cast iron skillet
No matter how many times I try to season this skillet there are spots scattered all over that won't "take" the seasoning (I am using canola oil or peanut oil). It was rusted in parts and I've scrubbed it totally rust free/washed it/dried it which is why I am trying to reseason it. I have tried seasoning it at high temps and low temps for long times and for very long times, with repeated applications of thin layers and NOTHING seems to get these spots seasoned like the rest of the pan. Am wondering if I should do the "self-cleaning oven" thing, burn absolutely all the seasoning off and start over.
Any thoughts welcome!
Unless you're vegetarian, I recommend cooking a mess of bacon in your pan, and let the bacon grease sit in the pan overnight. then clean out the pan using only water, no soap. Bacon grease is much better than veg oil when it comes to seasoning. After that you should just use your pan; the seasoning will build up over time. Mine used to have a couple of raw spots but they didn't affect performance and my pan is now well seasoned.
Or if you don't want to use bacon, use Crisco shortening. After a thorough cleaning, bake the pan for awhile to make sure it is completely dry before adding the Crisco.
I am assuming this is an old pan. I recommend always burning off completely seasoning on pans that you do not know what it is. I also warn that something could have been put in that pan that was not food related. Like using the pan to drain motor oil or anti freeze out of a vehicle. Definitely get it down to the bare metal and start over.
I agree with the bacon, always save the fatty ends for these occasions. Steel wool is to abrasive, I keep a green srubbie just for my cast iron. Yes, it will get greasy and black, wash it occasionally. DO NOT use vegetable oil for every day cooking, it leaves a residue that will foul your pan eventually (more elbow grease). Bacon, duck, butter fat, peanut, like that. No tomato based dishes. Cast Iron ware will last hundreds of years.
I'm going to guess that those spots are seasoned, just discolored from previous rusting, acidic ingredients, etc. If you're using the thin-film/high-heat method, there's really no way I can think of that the pan isn't getting seasoned all over. I give a skillet at least five trips to the high-heat oven when re-seasoning, sometimes more like 10. It takes at least five coats before any irregular looking patches start to fade and the surface begins to look uniform. Just my two cents.
[Edit: Looking at dixiegal's post I'd guess I'd clarify that with my above comments I was assuming you knew the pan's provenance. If there's a chance it could have been used for non-food purposes I don't know what to recommend. I know I wouldn't want to heat either anti-freeze or motor oil to 900 degrees in my kitchen oven!]