I need to paint the part of the car where the door sits when its closed ( i don't know what it's called, i think maybe they are called door jams but i dono)because of rust and have never painted before. What are all my steps? How do i know when i've sanded enough? Do i have to use an airbrush or is there an alternitive? because i dont have access to one

Thanks

 

rust? how'd that happen?

 

i dono i just bought the car a couple days ago

I'm not sure it's rust but it sure looks like rust. could just be paint chipping and dirt. But either way it needs to be painted again.