What stuff?I've seen it on pipe and that stuff is nasty. Grind it off for sure
All he said is that it's hot rolled plate...black mild steel.Black could refer to mill scale or a pickled steel, neither of which you would want on your food. If it is just mill scale you could grind, sand then season like a cast iron. However I'm not sure if it would be considered food safe. If it is a pickled steel I would not use it, if there are any micro cracks in the steel it will absorb the pickling then leech into your food.
What is millscale? Can I not just season them and be good to go?Your good. I'd take a grinding wheel and take off the millscale. Wire wheel won't cut it.
So this for sure needs to be taken off?Mill scale are the impurities that rise to the surface of the molten hot steel as it is rolled out and then allowed to cool. A sandblast, grinder or a very stiff wire wheel with some elbow grease can take it right off.
So this for sure needs to be taken off?