Recommendation? Wet vs. Dry Sharpening on Arkansas Stones

[VIXIVIXIV]

So, I just got a new set of Arkansas stones. From my research and personal experience, I am aware that dry sharpening causes swarf to build up in the stones, slowing sharpening. However, I have also read (albeit only from one forum post somewhere) that dry sharpening gives finer, more polished edges, as there will not be any stray metal shavings scratching up the edge (or something like that, as I do not remember entirely). As such, I have few questions:

1. Which sharpening practice creates smoother edges: wet or dry sharpening?
2. If wet sharpening, what are some recommendations for the best, or at least decent, sharpening fluid? [It could be water, mineral oil, etc.]
3. How can one remove swarf from an Arkansas stone? (I have another set I would like to clean out, if possible)
4. Does anyone have any recommendations for a jeweler's loupe or the like for examining the quality of knife edges? (I would also like to carry out some tests to directly compare wet and dry sharpening, hence question 3)

 

[bucketstove]

Hi,
The biggest reason to use lube is to keep metal dust out of the air (healthy lungs),
Second biggest is to keep the stone cutting longer (time+abrasive=$money$)
by keeping it clean ("dirt" masks/hides the abrasive)
and decrease friction/heat/wear ( oil better than water ).

If the oil is too heavy, you might need to thin it out, like 1 part baby oil , 1 part dish soap, 4 parts water A talk about lubricants for hard stones and a shave - caleb McCullough


Influence of burnishing on edge retention links and quotes the article you read about wet versus dry

The issue of wet/dry is about the apex smashing into mud on the stone in the final strokes -- solution isn't to apex/microbevel dry, its to wash the mud/slurry/swarf off and then do your final strokes.

Yes, loaded/worn stones will produce a higher polish, but at the cost of edge retention ... which isn't always important (razor shaving).



For cleaning, just like spyderco ceramic, scrub with bar keepers friend, or scrub with vinegar, then scrub with soap+water,
or deglaze the hard way which is just a a 20 second lapping/rubb to scratch a new surface


Regarding loupe, a 30x or 50x or 60x ebay/amazon deal (under $5?), maybe clipped to a smartphone, does a pretty good job (you can see in videos on youtube)

update: See the difference in pictures between a fresh and a worn 36 grit stone

 

[VIXIVIXIV]

Hi,
The biggest reason to use lube is to keep metal dust out of the air (healthy lungs),
Second biggest is to keep the stone cutting longer (time+abrasive=$money$)
by keeping it clean ("dirt" masks/hides the abrasive)
and decrease friction/heat/wear ( oil better than water ).

If the oil is too heavy, you might need to thin it out, like 1 part baby oil , 1 part dish soap, 4 parts water A talk about lubricants for hard stones and a shave - caleb McCullough


Influence of burnishing on edge retention links and quotes the article you read about wet versus dry

The issue of wet/dry is about the apex smashing into mud on the stone in the final strokes -- solution isn't to apex/microbevel dry, its to wash the mud/slurry/swarf off and then do your final strokes.

Yes, loaded/worn stones will produce a higher polish, but at the cost of edge retention ... which isn't always important (razor shaving).



For cleaning, just like spyderco ceramic, scrub with bar keepers friend, or scrub with vinegar, then scrub with soap+water,
or deglaze the hard way which is just a a 20 second lapping/rubb to scratch a new surface


Regarding loupe, a 30x or 50x or 60x ebay/amazon deal (under $5?), maybe clipped to a smartphone, does a pretty good job (you can see in videos on youtube)

Alright, thanks, you basically covered all of my questions. One follow-up question based on one of your answers, though. When you mentioned that dry sharpening will impact edge retention, from what sources did you draw this conclusion from? I just want to see what other members of the knife community have said about this, as Juranitch does not mention this at all, and am interested in an explanation of the mechanics behind the loss of edge retention. Also, will mineral oil work for sharpening? Just seems like it would be easier to keep the oil consistent and would involve less work to obtain a single fluid for sharpening.

Once again, thanks for all the information you provided; while it's probably been mentioned in other threads, the different points are too scattered to be efficiently found in the giant mess of information that is the Internet.

 

[David Martin]

Yes, Juranitch does state this in his book.
Mineral oil will work fine. DM

 

[VIXIVIXIV]

Yes, Juranitch does state this in his book.

Alright, given Juranitch's background, I think I'll just accept this.

One more question related to the edge quality, though: bucketstove mentions wiping off the floating swarf before final polishing on a stone with oil. Anybody have any idea of how edges created using this method compare to dry sharpening? (Think I'll just run a few tests with a cheap knife and the old stones and post the results, regardless of replies to this thread)

 

[bucketstove]

Alright, thanks, you basically covered all of my questions. One follow-up question based on one of your answers, though. When you mentioned that dry sharpening will impact edge retention, from what sources did you draw this conclusion from? I just want to see what other members of the knife community have said about this, as Juranitch does not mention this at all, and am interested in an explanation of the mechanics behind the loss of edge retention. Also, will mineral oil work for sharpening? Just seems like it would be easier to keep the oil consistent and would involve less work to obtain a single fluid for sharpening.

Once again, thanks for all the information you provided; while it's probably been mentioned in other threads, the different points are too scattered to be efficiently found in the giant mess of information that is the Internet.

Hi,
Well,
I linked one source (thats easy to source),
it has this picture,
with each subsequent rubbing/burnishing/realignment,
the retention drops , edge goes dull quicker than fresh

If you visit sites like cheftalks/kitchenknifeforums,
you can find similar reports from cooks/chefs,
they talk about how they can keep a knife sharp enough for food
for a long time burnishing/steeling/realigning, up to six months,
at which point it no longer works


The explanation is metal fatigue,
like bending a wire or paper clip back and forth,
at first its hard to bend past the yield point
but it gets easier and easier ,
wire turns floppy like rope,
and then the wire breaks

The very cutting edge, the apex on a knife is about 1 micron wide,
its like a 1 micron wire ,
its very easy to bend as its so tiny
1 micron is 1/1000th of a millimeter,
printer paper is 100 micron thick,
average beard hair is a little thicker around 120


So thats where the conclusion comes from,
from basic engineering principles,
easily confirmed with a paper clip

Also important to note is
the damage extends beyond/below the bend point,
the metal is being cold worked
and it can produce spectacular results
as can be seen in this video Issues sharpening a heavily abused knife - Yanagi-ba - Cliff Stamp whose thread has pics

 

[VIXIVIXIV]

Hi,
Well,
I linked one source (thats easy to source),
it has this picture,
with each subsequent rubbing/burnishing/realignment,
the retention drops , edge goes dull quicker than fresh

If you visit sites like cheftalks/kitchenknifeforums,
you can find similar reports from cooks/chefs,
they talk about how they can keep a knife sharp enough for food
for a long time burnishing/steeling/realigning, up to six months,
at which point it no longer works


The explanation is metal fatigue,
like bending a wire or paper clip back and forth,
at first its hard to bend past the yield point
but it gets easier and easier ,
wire turns floppy like rope,
and then the wire breaks

The very cutting edge, the apex on a knife is about 1 micron wide,
its like a 1 micron wire ,
its very easy to bend as its so tiny
1 micron is 1/1000th of a millimeter,
printer paper is 100 micron thick,
average beard hair is a little thicker around 120


So thats where the conclusion comes from,
from basic engineering principles,
easily confirmed with a paper clip

Also important to note is
the damage extends beyond/below the bend point,
the metal is being cold worked
and it can produce spectacular results
as can be seen in this video Issues sharpening a heavily abused knife - Yanagi-ba - Cliff Stamp whose thread has pics

Alright, I suppose I should tread more lightly now that I am heading into pedantry land, but here I go.

Reading the article that you linked, the author seems to use "burnishing" interchangeably with "steeling", as it mentions "burnishing" extending "the time between sharpening on a stone" (the emphasis is mine) and soon afterward quotes an article about the use of knife steels. For those who are just jumping into this thread or just need a refresher, steeling (or burnishing, as Cliff Stamp calls it) restores edges by folding a rolled edge back into position. I was aware that this would only work up to a certain point after which stresses created by the bending would cause the edge to undergo brittle failure. However, I wish to know the mechanics behind sharpening on a dry stone, as in that case bending is minimal, and the main source of metal forming is abrasion. Of course, obtaining this information is less than vital.

As always, once again, I thank you for the information that you have provided.

 

[bucketstove]

Alright, I suppose I should tread more lightly now that I am heading into pedantry land, but here I go.

Reading the article that you linked, the author seems to use "burnishing" interchangeably with "steeling", as it mentions "burnishing" extending "the time between sharpening on a stone" (the emphasis is mine) and soon afterward quotes an article about the use of knife steels. For those who are just jumping into this thread or just need a refresher, steeling (or burnishing, as Cliff Stamp calls it) restores edges by folding a rolled edge back into position. I was aware that this would only work up to a certain point after which stresses created by the bending would cause the edge to undergo brittle failure. However, I wish to know the mechanics behind sharpening on a dry stone, as in that case bending is minimal, and the main source of metal forming is abrasion. Of course, obtaining this information is less than vital.

As always, once again, I thank you for the information that you have provided.

Hi,
If you're talking a freshly conditioned clean stone that cuts at its rated grit level.
It will cut the same wet or dry, no measurable difference.

Used dry this stone will load ,
and once stone is loaded, coated with metal dust,
then it is no longer cutting it is only burnishing/rubbing,
and that will produce a more polished edge with less teeth
...

Rubbing is what unrolls and pushes the edge back into alignment, bends it back into shape, so burnishing/rubbing, yes, same thing,

 

[VIXIVIXIV]

Hi,
If you're talking a freshly conditioned clean stone that cuts at its rated grit level.
It will cut the same wet or dry, no measurable difference.

Used dry this stone will load ,
and once stone is loaded, coated with metal dust,
then it is no longer cutting it is only burnishing/rubbing,
and that will produce a more polished edge with less teeth
...

Rubbing is what unrolls and pushes the edge back into alignment, bends it back into shape, so burnishing/rubbing, yes, same thing,

Alright, makes sense. Thanks for drawing the link between the quotations on steeling and dry sharpening. If a rolled edge is sharpened on a loaded stone, then yes, I agree that logically, a certain amount of bending would occur, thus leading to a fatigued edge. However, I would like your comment on what you believe would happen in a number of other scenarios:

1. Even if a rolled edge is sharpened on a clean stone (wet or dry, as you claim; for the sake of this scenario, it hardly matters) some bending of the edge will probably occur. As such, would sharpening on a clean stone lead to some of the same effects of sharpening on a loaded one, in terms of edge retention? (I do believe such effects would be minimized, and mostly insignificant, but for the sake of argument . . . )

2. Would dry sharpening weaken an edge if it is only used for polishing after wet sharpening? I believe this shouldn't because the wet sharpening has already flattened the edge, so the dry sharpening would have a more minimal impact on edge retention.

 

[bucketstove]

1. Even if a rolled edge is sharpened on a clean stone (wet or dry, as you claim; for the sake of this scenario, it hardly matters) some bending of the edge will probably occur. As such, would sharpening on a clean stone lead to some of the same effects of sharpening on a loaded one, in terms of edge retention? (I do believe such effects would be minimized, and mostly insignificant, but for the sake of argument . . . )

Hi,
It depends,
is high force being used to sharpen?
is the damaged metal getting removed during sharpening?

One of the reasons advocated to start sharpening by cutting off the apex directly,
by removing the damaged metal and making a reflective flat,
so you're getting the most performance practically possible from your expensive steel.

The damage can be measured if you count when you sharpen or cut stuff,

2. Would dry sharpening weaken an edge if it is only used for polishing after wet sharpening? I believe this shouldn't because the wet sharpening has already flattened the edge, so the dry sharpening would have a more minimal impact on edge retention.

Hi,
I don't believe so, no,
and similarly I don't believe dry honing
would increase the amount of polish

The amount of polish increases because the abrasive is masked so it can't cut as deep
or because the abrasive is worn (rounded , not pointy) so its rubbing/burnishing

 

[jc57]

I don't get too much into the science of it. I have sharpened on Arkies both dry and using oil. I prefer the results when using oil. So far, my favorite is Norton Honing Oil. It's just the right viscosity. Try it both ways and see what you prefer.

 

[David Martin]

John, that's my thinking as well. Sharpeners may get a little more feedback when using them dry but with oil I believe the edge turns
out better. And no swarf is stuck to my stone. I merely wipe the stone and it all comes off, clean. DM

 

[Obsessed with Edges]

My own take:

Dry:
OK for quick & light touchups on the fly. Not of lot of heavy grinding done for this, so swarf buildup isn't as much an issue. But grinding speed will slow dramatically and nearly stop completely, if heavy grinding produces enough swarf. The stone will clog, and will need cleaning again to get it cutting efficiently. The 'polishing' effect of using a dry stone is likely just do to the clogging of the surface, so the abrasive can't cut as deeply. The metal swarf from the blade essentially burnishes the finish, instead of cutting. As the cutting efficiency of the stone slows down, there's also an increase likelihood of more burring, and additionally stressing the fine edge as the stone can't cut it as well, and the fine edge gets increasingly weaker as it's bent back & forth, instead of being efficiently cut away by the abrasive. I notice this behavior on ceramic hones as well, when trying heavier grinding on a dry hone. I've since started using a little oil on those as well, on the occasions when I do use them.

Wet with water:
Works pretty good; maybe as good as with oil, IF the water doesn't evaporate too fast. That's an issue in the dry environment where I live. If not kept wet all the time, swarf suspended in the water will immediately settle when the water evaporates, and clog the stone again, as with dry use. If I choose to use water at times, I make sure to do it at the sink, and very frequently wet/dip the stone in the water, to keep it wet at all times. Feedback is nice on a wetted stone, used this way.

Wet with oil (mineral oil):
I've come to prefer this the most. Even when the oil 'dries' a bit, there's still a residue of it on the surface, which keeps the swarf from sticking so tenaciously to the stone. Much, much easier to keep the abrasive cutting efficiently. Also much easier to clean up the swarf when done, by simply rubbing a little more oil on the surface with the fingertips, and immediately wiping away the lifted swarf as a result. A microfiber towel is great for this, as it really grabs any loose swarf and any other loose matter on the surface of the stone. As with a stone wetted with water, feedback is also very good when used with oil.


David

 

[cbwx34]

I would add oil but lighter than mineral oil. I found mineral oil too thick... a lighter oil (baby oil works well if you can tolerate the smell), or an actual honing oil worked better for me.

 

[Obsessed with Edges]

I would add oil but lighter than mineral oil. I found mineral oil too thick... a lighter oil (baby oil works well if you can tolerate the smell), or an actual honing oil worked better for me.

Those are all mineral oil; just different grades of it, at different viscosities. In particular, the USP/pharmacy-grade (laxative) type is a heavier viscosity than the type in baby oil, or something like Norton's honing oil, which I like the best.


David

 

[cbwx34]

Those are all mineral oil; just different grades of it, at different viscosities. In particular, the USP/pharmacy-grade (laxative) type is a heavier viscosity than the type in baby oil, or something like Norton's honing oil, which I like the best.
David

True, but most seem to associate "mineral oil" with the thick 'laxative' type.

 

[Obsessed with Edges]

True, but most seem to associate "mineral oil" with the thick 'laxative' type.

I'd originally associated 'mineral oil' with baby oil, myself; I think it was the first alternative I'd read about here, as used for sharpening stones. I was somewhat surprised to learn later about the 'laxative grade' stuff. And it's viscosity, being thicker, seems uniquely different and more of an aberration from the other 'mineral oils' I'm used to hearing or reading about, like honing oil, baby oil, 'sewing machine' oil, electric clipper oil, shredder oil, and food-safe types used for kitchen cutting/slicing/grinding machinery, etc., all of which are lighter (less viscous) grades of mineral oil than the laxative type.


David

 

[cbwx34]

I'd originally associated 'mineral oil' with baby oil, myself; I think it was the first alternative I'd read about here, as used for sharpening stones. I was somewhat surprised to learn later about the 'laxative grade' stuff. And it's viscosity, being thicker, seems uniquely different and more of an aberration from the other 'mineral oils' I'm used to hearing or reading about, like honing oil, baby oil, 'sewing machine' oil, electric clipper oil, shredder oil, and food-safe types used for kitchen cutting/slicing/grinding machinery, etc., all of which are lighter (less viscous) grades of mineral oil than the laxative type.
David

All I know is conversations tend to go like this...

Q: What should I use on an oil stone?
A: Mineral oil is a good cheap solution.
Q: Where can I get that?
A: At any drugstore... it's usually in the pharmacy section sold as a laxative.

p.s. You're guilty too... Olive oil for knife maintenance?

 

[HeavyHanded]

So, I just got a new set of Arkansas stones. From my research and personal experience, I am aware that dry sharpening causes swarf to build up in the stones, slowing sharpening. However, I have also read (albeit only from one forum post somewhere) that dry sharpening gives finer, more polished edges, as there will not be any stray metal shavings scratching up the edge (or something like that, as I do not remember entirely). As such, I have few questions:

1. Which sharpening practice creates smoother edges: wet or dry sharpening?
2. If wet sharpening, what are some recommendations for the best, or at least decent, sharpening fluid? [It could be water, mineral oil, etc.]
3. How can one remove swarf from an Arkansas stone? (I have another set I would like to clean out, if possible)
4. Does anyone have any recommendations for a jeweler's loupe or the like for examining the quality of knife edges? (I would also like to carry out some tests to directly compare wet and dry sharpening, hence question 3)

Personally I find an oiled stone to produce a better edge. The oil actually suspends the swarf, water does not unless it is mixed with a binder of some sort (like on a waterstone). On light touchups I don't see any difference, so it is likely caused in my opinion by the swarf buildup on the surface of the hone.

Whether the oil prevents mineral glazing, promotes mineral breakout on the surface, or simply prevent loading is another couple of questions - relative to an Arkansas stone it likely promotes easier tear out of the swarf and less loading. Many studies have shown that lubricant isn't really a factor at the point of contact, but does dramatically effect the steel at the boundary where it is being torn from the surface on either side of an abrasive grain. Put an entire field of abrasives together and you'll get a notable effect if you're looking for it.

And then because it suspends the swarf, less of it gets ground into the surface - this is huge.

Mineral oil is OK but the finer the stone the better a lighter grade of oil will work, on a coarse stone a very viscous oil can be used (Castor oil), but applied to a non porous stone it creates too high hydrostatic pressure to effectively grind. I like to use silicone oil in a very low centistoke, but most folk don't have ready access to that. Thin tool oil is OK. I have used pharmacy mineral oil as well - the viscosity breaks down with use a bit.

Normally if my Arkansas is plugged I'll lap it with lose silicon carbide and water. I've also had very good luck just letting it sit with a heavy film of oil on the surface for a number of minutes and wiping it off with a rag.

For a loupe, spend some $ and get a good quality one in the 12x range with a good diameter to let in more light. Squinting thru something the size of an aspirin is no fun.

The AM-14 or SW-10 is very much like what we use at work, and I have inherited several that have broken their bases.
http://www.magnifier.com/products-printers-loupes.htm

 

[HeavyHanded]

I'll also add my 2 cents on the effect of burnishing, even though it applies very little to this conversation IMHO - the effect of sharpening on glazed abrasives and plastic deformation on a smooth steel are going to be very different.

The effect of local work hardening with a smooth steel generally improves the surface "microhardness" and will theoretically/anecdotally lead to an increase in edge retention in steels that are not fully hardened. It will also draw out the edge, so if the rate of burnishing exceeds the rate of wear you'll have edge failure. If the rate of wear exceeds the degree to which the steel can be drawn, the edge won't get sharp. At some point even if these two factors are perfectly managed the region of the edge will have worn back and been drawn repeatedly out to where it is out of reach of further plastic deformation to restore the edge, at least at any effective angle. This is best case failure but you'd be hard pressed to achieve it due to the difficulty in burnishing with precision combined with uneven edge wear. In most cases the edge is overdrawn and fails in use like any wire edge.

It is used commonly in machining for final finish work to tight tolerances to improve surface hardness, in the form of roller burnishing. It used to be only used on unhardened steel and steels HT'd to low values, but it is currently used on steels up to low 60s RC to improve surface wear. There are obviously application differences between roller and ball burnishing and those in play either intentionally or deliberately when it comes to sharpening, but the poison is in the dose in this case.