An axe with a blunt edge becomes no more than an inefficient hammer, and indeed a great deal more dangerous as you struggle to use it. Always keep your axe sharp. For large 'burrs' a file is probably your best bet. Make sure you use the file correctly though, it will only work in one direction, it works when pushed, not pulled.

To sharpen your axe prop the axehead between a log and a peg driven into the ground. Always try to sharpen inwards from the cutting edge (to avoid producing any burrs). First use a file or rough stone to remove any burrs and rucks. Then finish with a smoother stone, using a circular motion. Don't drag the stone off the cutting edge, push on to the blade.

Turn the axe over and repeat the process, circling in the opposite direction.