To keep tips in factory new condition use this white polishing compound (Aluminum Oxide polishing compound) with either a leather strop or a felt polishing wheel. Actual sharpening of the edge can usually be done every six months to a year depending on usage. To help your tips last longer never use sandpaper of any sort to buff off carbon. Burning at lower temperatures will keep carbon build-up off of the tip in the first place and keeps the tips from oxidizing.