Axe Restoration Project: Part 5, Sharpening
The next step is sharpening our newly refurbished bit. Fig. a shows the tools we’ll be using. Clockwise from the upper left we have a small glass of water for cleaning our stone and files, a leather glove for safety, a diamond file, a diamond stone, and our axe head. First, a word about safety. Unlike knife sharpening, in which case you have a stationary sharpening implement, and hold the blade in your hands, sharpening an axe will most likely involve keeping the bit stationary, and holding the sharpening implement in your hand. This means that the blade and your hands are not moving in unison, making it much much easier to cut yourself. It is for this reason that we highly recommend wearing leather gloves while sharpening. They’ve saved our knuckles more than once.
There are many ways to sharpen every blade, and we are always exploring different methods and techniques. If you have tips or suggestions we welcome them in the comments section.
The first step involved with our bit is to remove the pitting along the bit edge that we mentioned in our previous installment. This we accomplish by clamping the head to a sturdy work surface and then taking our coarse (325 mesh) diamond stone and moving it into and across the bit edge, utilizing the full length of the stone (fig. b). Placing a hand at either end of the stone gives more control and purchase on the stone. If a more aggressive tactic is needed you may want to use a bastard cut file first before moving on to the diamond stone. We don’t recommend the use of a bench grinder for two reasons, the first being that they heat up quickly and can damage temper, secondly they will give the bit edge a concave shape which would need to be removed anyway. Concave, or ‘honed’ edges are too brittle and prone to chipping for use on an axe.
With the course stone we remove the pitting in the bit and begin to give it a convex shape. This is where things get trickier and opinions vary. We prefer to give the final edge of the bit a flat bevel of 20º per side. This flat bevel will allow for more precise and consistent sharpening since it gives our diamond files something flat to lay against. Some people disagree, saying that a flat bevel will impede performance, making the bit stick in wood. While the last 16th of an inch of bit will be flat we eliminate the ‘shoulder,’ the edge that demarcates the final edge from the rest of the blade, that is typically found on knives. We make the transition from final edge to the axe cheek a smooth and rounded one, even though the last 16th of an inch is a flat bevel.
Once we’ve established the convex shape we want we progress through the higher grits of our diamond files. The folding file we show here is a DMT double sided Diafold. The red side has a fine mesh of 600, and the green side has an extra-fine mesh of 1200. As mentioned before, we use these files so they are flat up against the blade bevel, utilizing the full length of the file and pushing into and across the full width of the blade. All of our diamond sharpening tools we use with water. Dipping two fingers into a small glass and rubbing it across the diamond surface is usually sufficient. We never apply water to the bit edge for safety reasons.
Fig. c shows a close up of the bit edge. The thin light areas on the edge are called ‘candles’ and they indicate a microscopic flat area on the very tip of the edge. You may have to look at the bit edge at various angles in order to see any candling. These candles indicate dullness and should be eliminated with continued sharpening with a diamond file. Be patient and persistent in your sharpening, it can take a fair amount of time at each stage to achieve a great edge. Whatever you do, do not rush. Rushing only leads to poor workmanship and possible injury.
A well sharpened bit should be smooth enough to reflect light like chrome. If you wish you can finish the edge with a fine waterstone and/or strop it with a diamond paste. The bit we’ve shown here is sharpened to a 1200 mesh diamond file. We may do some more touch up work on it later, but it’s plenty sharp for us at this point. We find it’s easy to carry our folding file with us in the field and it will quickly restore a nice edge.
Sharpening takes practice. As we mentioned earlier, we are always trying to improve our techniques. If you’re new to sharpening the best advice we have is to take it slow, and really pay attention to how every stroke of the file and stone effects your edge. You’ll soon get the hang of it.
Axe Restoration Project: Part 4, Surface Treatment
In our last installment we had just finished cleaning 3 different axe heads in vinegar and had assessed their individual pros and cons. Of that group of 3 we decided to move forward with the Jersey head. This head was in need of a very aggressive surface treatment in order to remove pitting in the steel as a result of rust. We’ll basically be removing a layer of steel from the entire head and exposing clean new steel beneath.
We begin by sanding down the entire head using a disc sander and 100 grit sandpaper discs. This is a relatively laborious task as a good portion of the head needed the removal of up to a millimeter of steel. Fig. a shows the the head about a quarter of the way through the first sanding process. It should be noted that we find sanding preferable to grinding. Grinding wheels tend to remove too much material too quickly. They also heat up faster and hotter than sanding discs and belt sanders. This excessive heat can damage the temper of the steel, especially where the steel is thin at the bit edge. In fig. b the head has been completely sanded using 100 grit. From there the sanding grits get progressively finer, from 100 to 120 to 200. After 200 we switch to hand-sanding using 220 grit, then 320, then 400, and finally steel wool. Fig c. shows progress after hand sanding to 320 grit. As I said before this is a rather aggressive and time-intensive treatment, but the results are worth it. It’s possible to continue sanding and polishing until the steel shines like a mirror, although we think this is a bit excessive. You’ll notice in fig. c that the edge of the bit has been left unsanded and some pitting is still visible. This is because in this particular case the bit does not need any reshaping, just a good sharpening, and we prefer to tackle that job with our sharpening tools. In the case of badly misshapen bits it would make sense to use a sander to reshape the bit edge. In extreme cases a grinder might be used but only slowly, carefully, and with a frequent dip in a pail of water to keep the edge cool.
Axe Restoration: Part 3, Post-Cleaning Examination
All of the three axe heads shown above have received 12 hour vinegar baths and a light sanding with a 120 grit block. Each have their pros and cons with regards to restoration. On the far right is the Michigan pattern we started with. The center head is a dayton pattern we’ve had lying around for a while. On the far right is a jersey head we recently picked up on ebay.
In addition to breaking down rust, vinegar adds a patina to steel. Different types and hardnesses of steel will take on different patinas. For instance the hardened steel at the bit end of the head tends to take on a darker patina than the softer steel of the rest of the head. Where these two hardnesses meet there is usually a difference in tonality. The line created by this tonal shift is called the hamon line. Additional time in a vinegar bath after cleaning will usually reveal the hamon line fairly clearly. The photos above show the hamon lines highlighted in white. Of these three heads only the dayton and the jersey show well defined hamon lines (the dayton shows two no less!). The hamon line on one side of the michigan head runs parallel and about 2 inches from the bit, but only covers the heel (bottom of the bit) on the other side. This may be evidence of an improperly hardened bit, or just a general lack of quality. For this reason I’ve decided not to continue much further on the restoration of this head. After some more sanding and polishing, and hanging it with a new helve it will make a fine show piece but it would not be first on my list as a hard working axe.
The dayton head cleaned up fabulously in the vinegar bath and barely required any sanding to remove corrosion. After pulling it from the bath a few good swipes with the fingers was all that was needed to remove the rust and reveal the bare steel. Unfortunately the poll of this head is terribly mushroomed. Originally this head was passed over for restoration because of the poll damage but the cleanliness and quality of the steel now warrants a full restoration. This could be a very nice axe. In the last shot you’ll notice some damage along the top of the head. In this photo it’s interesting to note that the steel stops mushrooming at the hamon line, and instead begins to chip. This is because steel becomes more brittle during the hardening process and prone to chipping. This head is also stamped as a “Zenith Cold Test” from Marshall Wells who was a distributor and manufacturer of hardware from Duluth, MN, but they were not known to make axes. It’s most likely that this is a contract axe made by another manufacturer (online speculation points to a Kelly Champion) and then sold through Marshall Wells with their own name on it. The last photo shows the double hamon line quite clearly.
Lastly, the jersey head on the right is badly pitted due to rust and corrosion. Most of the pitting is localized to the top inch and a half of the head which leads me to believe that it may have been left in standing water for some amount of time. This head is heavier than the other two, weighing about 4 pounds. While it needs quite a bit more surface work than the other two, this head is definitely on the list for restoration. It may have been neglected but it sure wasn’t used a whole lot. The poll shows only a few small dents and the bit looks like it may not have been altered beyond its factory condition. With some more aggressive sanding and polishing this axe could be restored practically to like-new condition. Stay tuned!
Axe Restoration Project: Part 1, Initial Considerations
It was 5 or 6 years ago that I acquired 3 antique axes from an architectural salvage shop. The helves in all were too loose for use, and the heads were badly rusted. They’ve sat in the corner of the studio on display until now. I’ve decided to restore one of these old axes, the Michigan pattern in the photos above.
Antique axes like these can be easily found at flea markets and second hand stores, and at a decent price. With a little elbow grease these axes could make a wonderful addition to your home or workshop. Many used axes are “no-name” axes, meaning they bear no markings, stampings, or etchings that would indicate their manufacturer. Many older axe heads were originally sold with stickers bearing their make and model. These stickers eventually wear completely away, leaving the heads nameless. When possible, especially if you plan on using your axe once it’s restored, search out axes of quality manufactures such as, Collins, Council, or Walters. A more complete list can be found on the U.S. Forest Service’s website. More historical information on axe manufacturers can be found at Yesteryear’s Tools’ website.
When selecting an axe to restore there are a few things to keep in mind. The condition of the helve and wedge are of no consequence as these will be removed and completely replaced. The helve may need to be cut off just below the head and either pounded or drilled out. Although, often times older axes will have very loose helves to begin with, requiring no more than a good tug or a few persuasive taps with a dead blow mallet to jolt them free. Since the replacement of an axe helve is a somewhat forgotten skill it’s very likely that a loose head is the number one reason people would stop using an axe and let it fall into disrepair.
The second thing to make note of is the overall condition of the head. Somethings can be corrected, such as the mushrooming of the poll or the dullness of the bit. Other things cannot be repaired, at least not very easily, like a misshapen bit. Sometimes through careless sharpening the curvature of the bit can be altered to the extent that to correct it would require substantial, and careful, grinding. Axes heads with damaged tempering should also be avoided. Temper damage is visible as a darkening in the coloration of the steel. Usually found along the bit edge, temper damage is often the cause of improper sharpening and the use of electric grinding wheels.
The last thing to think about is the final intended use of your axe. If it’s to be used for chopping and clearing it would be worth your time to search diligently and consider paying a bit more money for an axe in very good serviceable condition. If you plan on displaying your axe you probably don’t need to be too diligent in your search, although it’s always nice to have the best!
