So One of my cast iron pans, rectangle skillet to be exact was accidentally left outside. I use it on my grill and left it sitting on some bricks and forgot about it. It was there for a couple months.

So I followed the youtube recommendations of letting it go through the self clean cycle of the oven, steel wire wheel, then wash and rinse to get clean before heating then season.

But when I put it in the 200 degree oven for heating prior to seasoning, it rusts back up.

What am I doing wrong? it is a surface coat of rust but I know it is not supposed to be that way prior to seasoning.

The pan looks good during the process but develops rust damn near instantly.

Wipe it with whatever oil you are going to use to season and then heat on oven as you would normally do.

Dry it with paper towel then oil it before heating it.

Scrub, wash with vinegar, rinse/dry, coat with oil. Heat at 25F above the flash point of the oil for one hour.  This allows proper carbonization.  I like refined flax seed oil which has as FP of 375, so I do 400F for an hour.

When you season it in oven, rub with oil, place upside down with foil on rack beneath it to catch oil.
May need to repeat, upside down method penetrates porous iron better.

So I will give in another shot.

I will clean the surface rust off and dry it before putting it in the oven to dry and prepare for seasoning.

Or should I dry it and put some crisco on it before putting it in the oven?

This.  I also use Flax seed oil.  Small bottle from the local super market--$8.  Quarter-sized pour (1" diameter), and wiped down (spread around) with a paper towel.  Thin layer on everything--no drips.  1 hr at 450. Cool.  Repeat 2nd time and its good to go with a nice black non-stick coating.

 

I switched to flax seed oil too after reading quite an article on instructables. Self clean oven cycle took the factory pre-seasoning off them and I'm going on coat 9 of the flax seed oil. Very thin amount and bake for an hour. It's been a little time consuming, but they're starting to get slicker than owl shit.