I bought a couple of rusty 4 X 8 steel plates to make a welding table. I was going to sandblast them, but it would take weeks and a lot of sand using my small harbor freight blaster. Plus its real messy. So I decided to try Vinegar. I went to the $1 store and bought 5 gallons of cleaning vinegar. I got the loose rust off with my 7-1/2" grinder with a wire wheel. I built a dam around the edge with weather stripping. I then filled up the plate with vinegar. Let it set for a few days. Every so often I would run a hand wire brush over the surface. Had to keep adding vinegar as some did evaporate. Then I cleaned it off with my pressure washer. Came out nice. I am surprised vinegar actually worked.