Can a knife be sharpened with small circle motions instead of long strokes?

J

johnnyKnives

Joined
Sep 21, 2008
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I only ask because I saw this video:

[video=youtube;5cnk1A-PsgQ]http://www.youtube.com/watch?v=5cnk1A-PsgQ&t=4m15s[/video] (skips to 4:15).

Will that ruin a blade if you sharpen your knife with small circles? All I've ever seen is long strokes on rods or a whetstone. Thanks.

edit: will using a "normal" rock like that ruin the blade? Do you need a "pro" rod or whetstone?
 
I used to sharpen some knives moving the blade in circles, then I switched to pulling back the blade across the stone since it works better for me. Plenty of folks use a circular motion and it seems to give them good results. It's a handy way to sharpen when you've got a small sharpener and a rather large blade. Try it out for yourself and see if it suits you.

About using rocks, they'll work in a pinch. A regular rock is quite probably going to be more uneven than a commercial sharpener and might leave some marks. There are a myriad pocket sharpeners that are very convenient to carry, like DMT's credit card sized ones or just some wet/dry sandpaper (cheap, effective and takes up practically no space).
 
Yes, actually... you can sharpen a knife blade using circles instead of long strokes. Many people that sharpen freehand use a circular motion. It's one of the techniques that Buck used to recommend for sharpening their knives. They may still favor it. I haven't checked their web site or bought a Buck in some time so I can't say for sure. You can sharpen a blade to a certain degree with rocks... if you know what you're doing and if you use the right rocks. But you can also harm an edge with the wrong technique or rocks. Bottom line is that there are far more effective sharpening tools than rocks and they're still easily affordable and portable. The Spyderco Doublestuff stone that I travel with is thinner and lighter than the rocks he's hauling around and I would bet that it's a more effective sharpener for knife blades.

Axes and machetes, however, may be another story...
 
You can develop an eye for rocks that might be nice to use but try them out on your no-count knives first to see if they are worth fooling with. When we have been up to Lake Superior there are some shorelines where it is no problem to find nice hand size lake tumbled basalt stones. Some of them can be very good sharpening stones if you find a decent flat plane on one face or more.
 
Sharpening is really just about removing enough metal to return the planes of the bevel to a zero apex. Take that! So any motion will work up to a point. I would imagine that the results will vary a great deal depending on the knife steel and it characteristics as well as the stone or rock.

I admit to not viewing the video. I see it is an inexpensive Mora model that I have. Those are common and that one is $9. Scandi grind blades are especially suited, IMHO, to circular motion. You lay that flat wide bevel down flat and go to town.

I'd expect the worst thing that would happen by using a circular motion would be inconsistent results. Modern methods are all about forming a burr at the apex and then removing it. That's not going to happen with a circular motion. I suspect 10s of million of knives over the millenia have been sharpened this way. I however employ that motion only when removing a lot of metal on a reprofile or other such job.
 
With Silicon Carbide, Carborundum type stones circles are a real problem. With this material you must sharpen away from the edge, because, the material is so fragile that when sharpening into the edge it breaks down ahead of the edge, keeping the edge dull as you work. This is shown when you look at old Carborundum stones that have been badly dished in the center, almost always from a great deal of circular sharpening.
 
I learned how to sharpen a knife way back when I was a kid, using the small circle method. It works for me, and it's a fast easy way to touch up a blade quick. I carry a Eze-Lap model L diamond hone in my wallet with most of the red plastic handle cut away. I use it to touch up my pocket knife out anywhere if it starts to go dull on me. I'll lay the blade on the hone, and give it a minute on each side of the blade going from kick to tip, honing in small circles. Repeat as needed. Then I finish up by a quick strop on the back of my belt. It'll shave arm hair after, so that's sharp enough for me.

The small circle way of sharpening helps keep a steady angle while honing free hand. Something lots of people have a problem with. And you will be able to sharpen your knife this way a lot easier. I've taught folks to do this, who said beforehand they can't sharpen free hand. They were wrong. They could.

Carl.
 
A. G. Russell said:
With Silicon Carbide, Carborundum type stones circles are a real problem. With this material you must sharpen away from the edge, because, the material is so fragile that when sharpening into the edge it breaks down ahead of the edge, keeping the edge dull as you work. This is shown when you look at old Carborundum stones that have been badly dished in the center, almost always from a great deal of circular sharpening.
Click to expand...

REALLY! That is exactly what my grandfather had and did. He had an old stone that was indeed very soft and it had worn down to almost an hourglass profile. He spit on it. He was a man from a different age mind you...he was too old to serve in WWI when the time came (both my GFs were) plus he was a farmer and the sole support of his mother and the farmstead. The stone he had was probably 3/8" thick when new and when I got it long after he died, I'll bet it wasn't more than 1mm thick in the middle.
 
A. G. Russell said:
With Silicon Carbide, Carborundum type stones circles are a real problem. With this material you must sharpen away from the edge, because, the material is so fragile that when sharpening into the edge it breaks down ahead of the edge, keeping the edge dull as you work. This is shown when you look at old Carborundum stones that have been badly dished in the center, almost always from a great deal of circular sharpening.
Click to expand...
So based on what A. G. says above, edge leading strokes would be okay on a SiC stone when reprofiling but one should switch to edge trailing once an apex is established. This makes sense. Always good to learn something new.
 
I use a SiC stone mostly for reprofiling and bringing really dull knives back to an apex. They work well for this, cutting aggressively and fast. I switched from diamonds for coarse work after wearing out some diamond stones while resurrecting some sadly neglected cutlery belonging to friends. The SiC stones are inexpensive and widely available.
 
A. G. Russell said:
With Silicon Carbide, Carborundum type stones circles are a real problem. With this material you must sharpen away from the edge, because, the material is so fragile that when sharpening into the edge it breaks down ahead of the edge, keeping the edge dull as you work. This is shown when you look at old Carborundum stones that have been badly dished in the center, almost always from a great deal of circular sharpening.
Click to expand...

That aspect drove me nuts for a long time. I noticed it when trying to use soft Arkansas stones too. I'd 'grind away' at the edge, and could see a lot of material being scrubbed from the stone, but my edge would never improve. Good to hear I wasn't imagining things. :)

I have used a circular/elliptical stroke on pocket diamond hones with great effectiveness. Works especially well if re-bevelling small blades, such as on traditional pocketknives. When grinding the new bevel, I find it's easier to maintain the angle this way.
 
Using a rock to sharpen your knife won't do any harm. Though, It probably, won't give you a uniform finish like you'd see from an actual sharpening stone. I'd say, go outside pick up a flat stone and see what it does, for yourself.
 
The circular sharpening method is (loosely) called the cabinet makers sharpening method as most of them used it. My Grandfather was a cabinet maker and taught it to me. Yet, there is problems with burr formation when using this method during the edge trailing stroke. The edge leading stroke gives a cleaner edge. Espically with the SiC stones as Mr. Russell made mentioned. DM
 
From my experience, the circular method works very well for putting an expedient edge on a blade and for doing initial, coarse bevel work. The method of moving in circles breaks up the burr as you go, making it a little more difficult to tell if you've full reground an edge, and also makes it tougher to remove the burr (depending on stone type) as the trailing and lateral portions of the circle don't remove the burr as well as edge leading. On the upside the burr doesn't have quite the same lopsided characteristics of one done with a linear movement and for general use, they hold up well (longer) than a quickly ground edge using edge leading or edge trailing strokes (an edge that likely has some burring left over such as might be the case if sharpening on the go). It also seems that the burr created is a bit smaller than might be expected for the same amount of grinding done laterally. The grind scratches are erratic, leading to an edge that cuts a little erratic, but for field use very fast and effective (when talking about grinding with fairly rough grades of abrasive). Also makes the most of your grind time as the stone is always working on the steel. This might seem like a small deal, but when sharpening with stones found on the trail or waterway, a 20% increase in grinding speed could equal many minutes of sharpening, and if doing heavy repair work or sharpening a larger blade is worth considering. I've done some experimenting and for field sharpening machetes, hatchets, and axes, now use a circular method with the coarse side and then give it several fast scrubbing/back and forth passes with the fine side, finishing with some edge leading to completely remove the burr. At that point I apply some compound to a stick or branch and strop.
 
The irregular scratch pattern and/or burrs formed from the circular sharpening stroke can be cleaned up after the new bevel is ground, by finishing the edge with a few 'normal' edge-leading, heel-to-tip sweeping strokes across the hone. That's how I do it. I rely on the circular stroke just for expediently forming a new bevel, then clean it up in more typical fashion.
 
I don't doubt you guys are correct but I just never got very comfortable using the circular method. DM
 
Through trial and error, when developing my freehand technique, I've found that the circular motion works well. I do not, however, use the technique exclusivley. I mainly use the circular motions on my course stones and then use more uniform/consistent long strokes as I refine the scratch pattern.
 
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