Have you ever got ahold of those "powdery chunks of carbon"?
They happen to be just a tad harder that steel, Carbon is actually added to steel to make it harder. Granted there isn't much room to drill but I was going to do mine from the bottom up. Nothing on mine leaks, so I prefer to leave it alone.

A day late, A dollar short, and A half a mile behind...

pass me that crescent hammer...