After just 2 days of using my new carbon steel wok pan, I noticed something suspicious inside it:
Looking back on it, it was probably just burnt oil and nothing to worry about. However, I mistook it for rust, and began my arduous journey to get rid of it. (Let me know what you think it was and what to think of it in the future, please)
First I scoured the spots with water and plastic scouring wool, then added some dishwashing liquid and continued the process, but it had practically no effect on the spots even after tens of minutes of work. Eventually I just chose to nuke the pan and start the seasoning process all over again.
I decided to try soaking the pan in acid and filled it up with water, adding some grams of citric acid into the mix. After some 20 minutes of waiting and haphazard scrubbing, the inside of the pan looked shiny enough for me even though there were still some bits of crud left. I removed the acidic solution and, just to be safe, filled the pan with water and some grams of baking soda in order to neutralize the acid. (Looking back, I do not think this was enough)
After that, following the guidance of numerous internet guides (e.g. 1, 2), I wanted to temper the wok again. I assumed that the protective oxide layer formed while bluing the pan for the first time had been erased along with the rest of the seasoning.
However, after I had blued the pan and waited a couple of minutes for it to cool down, a horrible sight awaited me:
I am almost certain that this was rust—the infamous flash rust.
I was petrified. Too demotivated to start the process all over again, I tried to season the pan, hoping that the "rust" was just a harmless byproduct of the bluing process. (Though I had not seen it when tempering the pan earlier)
This ended just about as well as anyone could expect:
I had clearly botched the seasoning. In hindsight, I think I may have tried to polymerize the thin coat of rapeseed oil over heat too high.
Thus, my main problem is as follows: how do I prevent flash rust from appearing after tempering the pan? I quite clearly cannot just rub oil on it to protect it while it's at 350 degrees celsius (≈660°F)... Do I just have to cool it down really quickly with water? Also, what caused it? Acid residue?
In general, how should I proceed? Can I, or should I, even repeat the bluing process again while reseasoning the pan? How acidic should the initial nuking solution be; is more acid better, or less?