How would you sharpen a dull axe?

[Bo T]

I sharpen my ax mostly for chopping wood. I take the platen off of my HF 1x30 and put and edge on with successively higher grits.

 

[Ah Pook]

To keep an axe blade sharp I just use a flat bastard file and a two sided whet stone.

To rehab an edge, I will use a belt sander or more aggressive files.

I never use grinder on axe blades. The heat can mess with the temper.

 

[bill workman]

I usually start with a file working off the old edge then work from a coarse to fine grit sharpening like you would a knife.