Yes, clean it off w wire brush and TSP and water mixture, then dry with a paper towel. Look it over, and reapply if needed. Drivers door on cuda i posted my results with it. Had to reapply 4 times to eat the rust off. Personally i am thinking the naval jelly does an exellent job as well, just not thick enough for sticking to vertical surfaces. Both products turn crusty black where they have drawn the rust out. Thats your cue to scrape it off, inspect, and reapply. Look closely for black in the bottoms of the pits, if present, then you aint done yet lol