I went to deburr all the freshly drilled holes in my firewall last night, but then realised that the stainless steel would likely dull my deburring tool very quickly (that little countersink cutter on the hand deburring tool that you spin around in the hole). So I ran a scotchbright wheel in my hand die-grinder over the surface of the holes a few times. This did an OK job, but the edges of the holes are still a bit sharp.
What have other people done about this?
What have other people done about this?