[Mjminino]

I haven't heard of using the razor blade on primer and paint. I have heard about using it on clear though. Not saying it wouldn't work, not to mention primer isn't that hard to sand. Just don't sand THAT part alone as you'll put a dip in the primer that you'll see later. (I don't know what you know and don't know when it comes to painting) Sorry if that sounded a$$ish