Originally Posted by krisbman
An 8 out of 10 is not going to be achieved by touch up paint in spots that large
It is good to stop the rust but, for an obvious spot like a hood, you will be able to tell.
Now, you CAN mask it somewhat by feathering the area with sandpaper, applying the paint, color sanding, and then applying clear but, even then it will not look fantastic.
If you are doing something like a rocker or a door jam, don't worry too much about perfection.