Here is the tool I use to strip the paint off of metal for grounds. You can get them from aviation tool suppliers and they come in all different sizes.
You drill the size hole you need first then chuck one of these into your drill and it leaves a perfect circle of stripped paint. Here is the finished hole. All of the bare metal is covered by the ring terminal.
You drill the size hole you need first then chuck one of these into your drill and it leaves a perfect circle of stripped paint. Here is the finished hole. All of the bare metal is covered by the ring terminal.