How to reprofile an axe using simple hand tools

By | 4th November 2020

I bought some simple Bahco hand axes to use if/when I begin teaching spoon carving. I chose them on the basis that they are a reasonably well respected brand and I have seen what Barn the Spoon can do with one on the spoonclub.co.uk videos (Highly recommended. If you’re a beginner and you’re not sure about signing up for a subscription, the lifetime basic membership is extremely good value with videos covering all the basics you’ll need to get started).

They are also cheap. I think I paid less than £12 each for these. You can pick up similar, cheaper ones from most DIY stores but the quality is unknown and often poor in my experience.

As with all of the off-the-shelf general purpose hatchets (i.e. not those sold ready for carving like those from Wood Tools or Green Haven Forge or fancier hand-forged carving axes), they come with a grind which is just about adequate for splitting kindling. They are blunt. You could not cut yourself on this easily. If you got your hand in the way while chopping, you’d get a nasty bruising injury, definitely not a clean cut.

Blunt edge

You could not carve anything with this. It’s essentially rounded.

There are many ways to sharpen an axe. I have a variety of angle grinder (with flap disks and grinding disks), bench grinder, a couple of different belt and combination disk sanders. The risk with using a mechanical method is that it’s easy to over heat the edge as you’re grinding away metal. This will make the steel lose its temper and so will you.

N.B. When steel edge tools are made, they are generally hardened by heating up past red hot and then cooled rapidly (by quenching in some form of oil, usually). This makes the steel very hard, but brittle. It is then “tempered” by heating up to a lesser degree and quenching again. Getting the metal too hot by friction will mess with this heat treatment process, usually meaning that it softens and won’t keep an edge very well, “losing its temper”.

It is quite possible to use mechanical means to regrind an axe, but you have to be careful about keeping it cool by dipping the edge in water frequently. The other problem that power tools (or plugged in tools as Amy Umbel calls them) is that by making the process faster, mistakes happen faster and the consequences are faster.

It is not too difficult to use hand tools to sharpen an axe, even re-profiling or re-establishing the bevels. It just takes time and some effort. I chose here to use a pretty cheap file and some wet-and-dry sandpaper to keep it cheap and accessible for anyone.

Poor unloved file
This file hasn’t been used much, but was not stored well and got pretty rusty. It still cut surprisingly well.

The file worked well on this Bahco axe. The steel of the axe is pretty good but can be filed relatively easily. If you are restoring an old hatchet by Elwell or other makers, you may find that it doesn’t file easily. Either just take your time or do the work with lower grit abrasive paper. It will get there, but it will be slower.

It is easy to fuss about the best angle for a carving axe, but something I liked from Barn’s videos on the subject was that the width of the bevel is important. With all our carving tools, a lot of the technique is to use the bevel to guide the cut. A simple approach to the axe is to set the bevel to be about 10mm. Here I have simply coloured in the first 10mm back from the “edge” with a Sharpie (other permanent markers are available).

Bevel coloured in with sharpie

It really helps to be able to clamp the axe down to something. I used speed clamps to clamp it down to an old workmate. Having something underneath to lift the edge up, and having it protruding over the edge of the work surface helps.

Being on my own, I found it next to impossible to capture the action needed, but the best option for this is to use “draw filing”.

A great, short video Eric Hawkins demonstrating the technique here:

The grind on these axes tends to be fairly convex. i.e. somewhat domed. We’re aiming for a flat grind so the first objective is to take down the high point. Make some fairly light drawing strokes with the file until you can see that you’ve removed some marker pen approximately in the middle of the bevel you’ve drawn on.

Then, just keep working back and forth until you have removed all the marker pen on one side, establishing a flat, even bevel as best you can.

Flip the axe and do the same thing on the other side. In addition to removing all the pen, you are looking to make sure that the two bevels meet up to create an edge. Keep filing until you are creating a burr.

This is already sharp enough to do some serious damage. To carve, though, it’s nice to get it a bit sharper and have a fairly smooth, polished bevel. It’s easy to obsess.

First, re-colour in your bevels. The file will tend to leave pretty heavy scratches and we want to get rid of them.

You will need a few grades of wet and dry paper. The deeper scratches from the file will need a lower grade, and then the idea is that each subsequent grade will remove the scratches left by the previous one. You will probably need something like 160, 240 and 600 grit. I should have noted what I used, but I didn’t.

You will also need something with at least one good flat side to wrap the paper around. Wider makes it a bit easier to keep it at the right angle, but too wide and it’s hard to follow the curve of the blade. I just used a bit of an old chest of drawers from the shed. A piece of battening would do. 2×4 is probably a bit big.

Wrap the coarsest grade of paper tightly around your block. Try and keep it flat against the bevel you have established with the file and rub back and forth along the length of the bevel. Try not not rock it back and forth across the bevel as you go, this will round it off.

Again, keep going until you have removed all the pen. The other consideration is to try to ensure that you are creating a burr, sometimes referred to as a wire edge, along the whole length of the cutting edge. This is where you are basically pushing a small amount of metal over the edge to the other side. This indicates that the two bevels are meeting at a hard edge. It will get removed by subsequent grits and with stropping or even in use.

Here is the bevel during working with the first grit of paper.

After a couple of different grits

Here is a pretty good example of a wire edge. This is extremely delicate, almost like metal leaf. It will cut you, don’t go near it with your fingers!

Wire edge

Here it is basically done.

I used the preceding grits dry, as it is less messy. For the final grit, I used the wet and dry paper with a little water to lift off the swarf and make it easier to see the scratch patterns. This is 600 grit, I think.

You can keep going with successively fine paper, and then a strop, but it’s not really necessary. A test chop into fairly dry oak shows how effectively it will now cut.

One thought on “How to reprofile an axe using simple hand tools

  1. Dusty Hicks

    Well done. I have a Gansfors Bruks that needs this treatment. Thank you!

    Reply

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