Body Work Tutorial

That 50 grit created some wicked swirl what ill have to work out. But yeah the red primer underneith you can see that poking though. Also it may be darker beings the grey is over the top appearing to be darker. Besides where I broke though to the metal what ever is under the top coat seems solid. But Ill try your idea and see. But about the grit size what should I use between the 50 grit I used and 180? 80 or 120?