Before using an ax, whether old or new, you should sharpen its blade. Clamp the head of the ax, edge up, in a vise. Use a medium-cut mill Me, never a power grinder. Hold the file flak against the blade. Draw the file upward toward the cutting edge, lifting off at the end of each stroke.
File on both surfaces, rounding them to a convex profile. Retain this profile to the corners of the blade; don’t taper the corners. Check the edge by sighting down its length.
Bright spots indicate dull areas. File these until the edge looks almost invisible. Hone the edge with an oiled, round ax stone, moving it in circles. Use a fine grade of steel wool to apply rusk inhibitor or lightweight machine oil. When the ax is not in use, protect its blade in a leather sheath.