Sharpening

Welcome to the axe and hawk forum Cutlerylover. What are you sharpening?

Best regards

Robin
 
I've got an el cheapo 1X30 table top belt sander from HF that works wonders for my tomahawks and other sundry instruments. 40 bucks aint bad and I use the heck outta it.
 
There is a lot of different ideas on sharpening. most are fine. dig through this forum, you will find sharpening info and lots of other good stuff
 
Ookami said:
Beltsanders can ruin your axes, don't use them.


Ookami
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How do belt sanders ruin axes, overheating? What's your preferred method? I have a bunch of old axes being shipped to me and I'd like to know the best way to get an edge back on them.
 
Belt sander/grinders do a great job on axes, hawks and knives , it's not the sander you have to worry about it's the person using it ;-))) Keep the steel cool, go slowly, don't slip. ;-)

Regards

Robin
 
I use a medium bastard file to fix dings and nicks or to put the edge on(cold steel ;)). Then I use a wood backed strop with sandpaper on top. 400 grit to whatever I feel like stopping at that day. Usually around 1000 grit. Then I strop with black and then green Bark River compound. To keep it sharp I usually start with 600 grit or so and go up from there. If it's not too dull just a stropping will do.
 
Pipeman said:
it's not the sander you have to worry about it's the person using it
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Yes, overheating is the problem - unless you have a coolant like water or something similar that is constantly applied (a dip now and then is not sufficient). An experienced maker can minimize the damage done by a beltsander. Yet, especially low alloy carbon steels will suffer from the heat.

I know all the arguments, like the blade does only get luke warm, etc. It is not the blade you have to worry about, it is the thin strip of metal that makes up the edge. Sure, the steel will not get soft like molten butter, but it will get softer. You can also sharpen bronze to a razor sharp edge, but it will not hold that edge like a well heat treated steel blade.

To me it's just not worth the gamble. Especially since most but the hardest axes are workable with a file. Shotgun is on the right track here.
 
Pipeman is right on. It is the person using a sharpening system and not the system employed that is important. For the beginner a grinder or belt sander will probably mean a damaged edge. However, many people with experience can match the job done with a file and stoning. I always finish my edge by stropping with leather.
 
Ookami, what type of file or files do you use? I have a few "bastard" files sitting around, will those work? Coarse, medium, then fine? I'm curious about your process because I'd like to give it a try.
 
Hey guys, it's your stuff, do what you want. I am going to trust the findings of Dr. Herbert Weisshaupt who has earned a doctorate in physics and is a member of the German Messerforum. This guy knows what he is talking about. He is not a maker or a professional sharpener who tries to sell his customers a quick&dirty method that will make the knife sharp quicker and keep his customers coming back more often - the "worksharp" gizmo comes to mind that sends sparks flying all over the place, just watch the commercial on youtube.
When asked by another member if it was at all possible to sharpen a knife on a dry belt (with the right experience, equipment, and lower speed) without drawing (some of) the temper at the edge, his short answer* was NO.

So I am going to stick to sharpening methods that aren't detrimental to the edge holdig ability of my tools, thank you.


Ookami

*The long answer was that it might be possible with (experience etc. and) constant dipping of the blade in water, provided the steel is especially resistant to annealing (like HSS, 440c, or 154cm). Axes - and most knives/tools for that matter - are not made from these steels.
That said, you can use a belt sander to carefully reprofile your knife, b/c the damage done to the edge will be removed the next time you sharpen your blade properly (i.e. with a water cooled grinder or on a good ol' benchstone).
If you sharpen your knife on a dry belt the very edge will always have less edge holding ability than it could have. The same goes for the guys who use a buffing wheel to knock off the burr or strop the edge.
For those whose German is up to the task, you can download his paper here:
http://www.messerforum.net/attachment.php?attachmentid=35835&d=1182286243
(you may have to register first, dunno)
 
@trailmaker: Bastard files are just fine. Which file you start with depends on whether you need to repair a nick, reprofile the edge, or resharpen. After you are done with the fine file (you raised a burr on both sides of the edge), you switch to an axe stone to finish your edge. Stropping on leather will remove whatever burrs are left and give you a razor sharp edge.
A loaded leather strop can also be useful to keep your edge in good repair. If you do need to touch up your edge, it is often enough to start with the stone if the profile of the axe is still good.

To learn about sharpening An Axe to Grind (http://www.fhwa.dot.gov/environment/fspubs/pdf/pdf99232823.pdf + youtube) is helpful, especially for beginners.


Ookami
 
I only use a file for taking out dings, or fixing (reprofiling) a dull, newly purchased axe edge.

For using axes that have become dull, I use a Harbor Freight aluminum oxide stone about 6in. long. I lay it on top of my Sharpmaker stones @ 40 degrees, and sharpen in a circular swirling motion till I have achieved a basic, coarse type of sharpness. For me, this is less than 5 mins. of casual work.

Nicer axes(like GB) get the grey/brown sharpmaker stone next. Works great.
 
At the Gransfors factory:

Slowstarter said:
Today me and my family visited the Gränsfors Axe factory...
07.jpg

...
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And at the Wetterlings factory (tour photo from Garrett Wade):

61121_435044642380_180736467380_4902993_1938151_n.jpg
 
I know, I have been to some of the OEM makers in Japan, they do it too. Leatherman does it, Böker does it, most other makers (industrial and custom) do it. However, that doesn't make it any better. Like I wrote in post #14 it is economical.

In the paper I linked to, the temperature that occurs at the very edge is estimated - by various experts in the field - at 600°C (1112°F). That may sound like an exaggaration to the layman, but if you take into consideration that ppl make fire by spinning a stick on a board with their bare hands (and I am darn sure, they won't come even close to 1725rpm), it should give you some food for thought.

Even if you have an experienced grinder that uses all precautions, the hardness at the edge will drop by 5-7HRC on a dry belt. This doesn't sound like much, but considering that many users here on BF would very much prefer 60HRC over 55-53HRC (in their knives), I do think it is significant. A documented example can be found in the German MesserMagazin. They had a CS Trailmaster bowie tested and the scientists sawed the blade in half (with cooling of course) and tested the hardness at various locations along the surface of the cut from the back of the blade to the edge. They found that hardess increased from the back to the front but fell again at the edge. At the time the Carbon V knives were made by Camillus which also was a famous and respected American company.

This damage can be repaired with successive sharpenings. In fact, there have been many reports (about several knife models by different makers) by ppl who said that their knives "got better" with sharpening, meaning they removed the damaged portion of the edge. Indeed, I have myself experienced the same with my CS Kudu. I also have seen the opposite: a guy who tried to tell me that Opinel knives wouldn't hold an edge and that Nieto were the shiznit. I soon found out, that he dry sharpened the knives. The Opinels with their thin blades (heat from sharpening dissipates slower in thinner blades) and carbon steel were much more damaged by his sharpening than the relatively thicker Nietos with their thicker 440c blades.

That's why I think that it is ok-ish for factories to sharpen their knives that way. Also, you can use belt sanders where you need to abrade a lot of steel to repair or reprofile a blade. I have done that, too, but the actual sharpening should be cool.


Ookami
 
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