Everyone’s favorite Canadian is at it again. This time, [AVE] needed to cut a large hole in a stone countertop. They making coring bits for this, but a bit this size would cost upwards of $400 ...

If you prefer to sharpen it manually, use a diamond sharpening stone. Place the smaller of the two faces of the unibit flat against the edge of the stone and slide it back and forth to hone it.