If you have a log fire, then you probably spend quite a bit of time chopping logs with an axe. You might own a big felling axe and or a small hatchet, but whichever you have, the same rules apply. A sharper axe is a safer axe. When axes get blunt, accidents happen. This sounds counter-intuitive but it is true. Sharp axes tend to chop where they are aimed, whereas blunt edges bounce up, veer off and go in unexpected directions. It is on those ocassions that most accidents happen and accidents with axes are no laughing matter.
There are plenty of tools that you can buy to sharpen an axe, but there is really only one that you need. A sharpening stone is how axes have been sharpened for millennia and nothing we have invented since has really replaced stone.
The closest we have come is a case hardened bastard (I’m not being rude, they are called bastard) or second cut mill file. Mill files are the standard metalworking file you can get in any hardware or DIY shop. You can use these on seriously blunt axes, but even then you are going to have to finish off the process with a stone. Personally I just use stones on my axe heads as even bastard files are too rough in my opinion. However, this is because I sharpen the axe after each use (just a few seconds honing each side of the blade) rather than let it go really blunt. If I was starting with a blunt axe I might consider a bastard file as a shortcut to save me half an hour with a stone.
It might seem that a power grinder would be a good tool for sharpening an axe, but sadly they are just too likely to damage the edge to be the most sensible choice. Do not use power grinders to sharpen axes. You can use them to grind away rusty surfaces but again, be careful. A key problem is tools such as power grinders or high speed rotary tools produce so much heat at the point of contact that they soften the cutting edge and without retempering by a blacksmith the blade will now forever be soft and will never retain a sharp edge. I have a dremel myself and the urge to use it is strong, but I know the result would almost inevitably be an axe only fit for the scarpheap.
When it comes to axe sharpening, it’s all about angles. Getting the acute angle between the stone and the blade edge right is really all you need to know. Get this right and you will soon have a perfectly sharp axe blade again.
Please be careful whenever you are using or sharpening an axe. Complacency can lead to disaster. I know because I almost lost my thumb. Even as I write this two years after ‘the axe incident’ I can see a couple of very clear scars at the base of my left thumb to remind me to be careful.