My drivers fender is pitting and i sanded down to the metal and its still there. My question is if i primer over top of it than paint will it still come through, im guessing yes.

Secondly if i use like some rust bullet or some other type of chemical can i paint over that.

Thridly should i just put a thin layer of fiberglas over top.

I want to do it right but dont want to cut cuz its near where the fender and front bumper connect.