It turns out that a hot solution of alum (ammonium aluminum sulfate), which is available in the spice rack of your local supermarket, will dissolve the steel drill bit without reacting with the brass.

So it’s always a joy to pick up a new trick, especially one as simple as putting a hardened edge on mild steel using a drill bit as a filler rod. This tip comes to us by way of [Jody], aka ...

"The big challenge is reentering the hole. There is no motor or anything like a remote control for the drill bit to get into the spot," Fulton said. "Instead, all that steel pipe is like a wet ...