hey, i recently was trying to change my own tip, when i was using the ultimate tip tool to clear the side of the tip with the sandpaper, i think i scratch the ferrule, although now the ferrule is whiter, but it have a rather rough feel. is there any way for me to smoothen it.. make it like normal again? i dont like the feeling of a rough ferrule. and how do i prevent it next time when i change the tip?