Against the Grain
I was grinding out some rust on the door jams that was pretty bad with a drill and a course wire wheel. I would grind down pretty far, then use some naval jelly to help remove some of the rust. wipe off after 10 mins then start with the wire wheel again and do that a few times. I got it so it was mostly metal, but in some of the pits there was a black substance . wouldn't come off with the wire wheel, wouldn't budge with some 60 grit sandpaper. tried some steel wool on it. I'm not really sure what this is. is this a ferric compound that was created due to the naval jelly being on it? It it doesnt seem like rust, as its hard and wont budge with the wire wheel. I've never fixed spots that were this bad before.