Stones direction? Uniform or circles?

Hey Nicko,

I don’t have a micro-scope I use a 14x jewelers loop but the reason some go up/down or in a circular motion is, I’ve heard from some, that not breaking contact with the blade can help stop micro chips in the blade, but with the wicked edge a lot of us use a method called scrubbing, up/down or in a circle, to raise a burr before beginning your progression or refinement if you will.

Some also change direction of the scratch pattern to help identify when you have erased the scratches from the previous stone. The direction of the scratches does have an effect on the cutting edge, that I do know from experience. With the knife in the clap of your WEPS the scratches that go up and away help the edge in a slicing motion since most people with draw the knife toward them when slicing, while if your scratch pattern is up and down, 90 deg. to the edge it helps with a push cutting motion.

Things like this are as much preference as any one thing. Through experimentation and advise from folks who have been down that road, you will find the methods that work best for you personally.

If you sharpen for others you will find that slight differences in some knives, angle – refinement – scratch patterns will suit some better than others. It helps to know who you are sharpening for and how they use, maintain, or abuse their knives.

One reason I use a sweeping motion, one stroke on one side then one on the other is I believe it helps keep the edge straighter and more consistent down the length of the blade and it also works the burr off as you go thru your stones. A lot of this is still personal preference.

Hope this helps

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NotSharpEnuff, wickededge

Welcome to the forum, Nicko. Good to hear you’ve used your WEPS quite a bit already. I think the movements you make a quite personal, but there are some commons. Personally I most often use the swing movement you often see Clay make in his videos. I only use the up-down movements with my first grit and only if it’s difficult to make a burr (i.e. I have to remove a lot of material). I think that otherwise it is too easy to knock out carbides from the edge. Some people even go so far they only make edge-first movements.

And yeah, a micro-bevel can be great. Makes an edge stronger and easier to maintain.

Success and don’t hesitate to ask any more questions.

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sksharp, wickededge, Nicko

There’s some evidence that horizontal strokes (parallel to the edge through part of a circular motion) will actually damage the edge. Vertical strokes leave micro teeth where a point of diamond grit breaks through the edge.  The same point of grit running parallel will leave scratches at the apex that are parallel to that apex, leaving long sections of ragged edge.

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sksharp, Nicko, Organic

I use different methods depending on what I’m doing, reprofiling, sharpening, touch-up, or polishing. A USB microscope is extremely helpful to see what I am doing no matter which method I’m using at the time. Generally I start each stone grit pair with a scrubbing technique. Then I observe the scratch pattern with the scope to make sure I’m lined up correctly and working on the bevel. I want the scratch pattern to be across the entire bevel. If I’m high or low I check my arm set angles or adjust my grip on the paddle, up or down to apply the scratches correctly where I need them. After I’m sure I’m applying the scratches where I intend them to be, then I chose the method or pattern that lets me achieve the results I need with the least amount of scratches to the knife. For me, which ever direction or method I’m employing, proper technique is the most important issue which is keeping the stone flat and centered on the bevel and not letting it roll any or slap against the steel as I move it across the metal. I’m trying to keep the stone flat against the narrow bevel and maintain even light pressure throughout the entire range of stone movement whichever direction or method I’m using at the time. I believe the least amount of scratches you use then there’s less to remove with the next finer grit in your procession. Recently I’ve been trying to minimize the direction changes of my scratch pattern thinking that if all the scratches are in the same direction as I progress up the grits I should be able to avoid those random cross scratches that sometimes plague us later on down the progression causing us to back track a grit or three to remove that random deep scratch. Direction changes are often used to make it easy to determine if you’ve removed all the scratches for the previous grit but your applying a lot of new scratches obliterating the previous alternate direction scratches. I believe with the microscope I’m able to see the deeper previous stone’s scratches are obliterated while avoiding changing directions to do this. You also will be removing less metal which may mean something over the life of a good knife. So far my personal verdict’s not in but I’m using this technique with good results. I really believe it’s saving me time to achieve good final results.

Hope this may help

Marc

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NotSharpEnuff, Scott DF, sksharp, Mark76, currenthill, Nicko

Marc H wrote:

Recently I’ve been trying to minimize the direction changes of my scratch pattern thinking that if all the scratches are in the same direction as I progress up the grits I should be able to avoid those random cross scratches that sometimes plague us later on down the progression causing us to back track a grit or three to remove that random deep scratch. Direction changes are often used to make it easy to determine if you’ve removed all the scratches for the previous grit but your applying a lot of new scratches obliterating the previous alternate direction scratches. I believe with the microscope I’m able to see the deeper previous stone’s scratches are obliterated while avoiding changing directions to do this. You also will be removing less metal which may mean something over the life of a good knife.

Please consider that the scratches from prior grits are quite deep and are really difficult to remove with stones more than one grit step finer.  Also consider that these deep scratches are not just cosmetic flaws, but extend all the way to the apex, where they have produced a deep notch in the apex.  If you truly can discern between scratches as to which grit produced it, good for you, but if miss it, you’re in for a lot of stoning.

While we usually see changing direction in the scratch pattern as a means of most easily removing the visible evidence of the prior grit, the fact is that those scratches tell you something about the condition of the edge at a macro level.  A less-than-perfect polishing job will certainly produce excellent practical cutting edges,  but a deep scratch in the bevel field is usually a deep scratch at the apex.  You may find that these points along the edge will snag when trying to cut a less-than robust sheet of paper.  Those of us who are possessed by the obsession of achieving pure cutting nirvana will take that as a sign of failure.

For knives I sharpen to be working tools in the field, I usually use only four grits: 400, 600, 800 and 1000.  I have my stones stored on a rack of  pegs, with each stone mounted with a top and a bottom, left side and right side.  This means I always hold the stone in the same hand and the same direction.  I have a sheet of paper hanging on the wall next to me, telling me what direction to use with each grit.  For instance, 400 is always down and toward me, 600 is down and away from me, alternating similarly with the 800 and 1000’s.  For stones under 1000-grit, I always use down-strokes (edge leading) if the stone will hit the apex.  If I’m not there yet, I’ll use scrubbing strokes to speed the process along.  The objective is to not rip any particles free at the apex, which is much more likely with an up-stroke (edge leading).

For 1000-grit I will generally use the same down-strokes, but will switch to gentle scrubbing strokes as I near the finish. When I get to the last few strokes of the last grit, I’ll do alternating down-strokes; left-right, left-right, etc. for maybe 5-10 strokes on each side.

After 1000-grit, I usually jump to 6-micron film.  Film requires that you use up-strokes to keep the edge from digging into the soft film, but by that time, you’ve eliminated the raggedness of the edge and the film being used edge-trailing will not add to it.

You can start out with the 14X loupe, but try to find an old laptop and monitor and a USB microscope. It will add hugely to your experience and confidence.

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sksharp, Organic, Nicko, Mark76, currenthill