I just found this rust forming on my rear tub. as you can see in the picture i already tried to fix it temporarily. I used a wire wheel and grinded it down to bare steel. then applied 2 coats of primer and 2 coats of paint. This was 2 weeks ago. as you can see the rust is, of course, coming back.
anyone have any tips or tricks on what i can do to fix this permanently without having someone cut and weld?