Welcome! Log In Create A New Profile

Advanced

Suehiro 'Chemical' stone, #320

Posted by CliffStamp 
This forum is currently read only. You can not log in or make any changes. This is a temporary situation.
Suehiro 'Chemical' stone, #320
September 09, 2014 11:53PM
This is an very basic and traditional stone : [www.toolsfromjapan.com]



It comes with a cartoon in the box which I believe notes that if you drop it that it can break. It doesn't apparently get sad or angry like the Shapton Pro.

Quote
TFJ
A simple, inexpensive coarse stone suitable for correcting chips and excessively worn edges quickly and without fuss.

This particular stone is quite 'old school' in the way it works, expending stone material in order to work quickly, so should be considered as 'very soft' and 'extremely muddy', which is preferred by some sharpeners, and does mean that it will not tend to leave significant scratches, making further refinement easier when the appearance of the edge and surrounding surface is important.

206 x 63 x 33mm.

(Note; the number on the stone is the product number, not the grit.)

The last part is kind of interesting because there is some discussion of this on the line and everyone just refers to it as a 800 grit stone as it says #800 on the box which Stu notes is a part number not a grit reference.

Now is is a 320 or an 800? Here is the stone :



Ok, you can't see anything like that as it is all white on white, adjusting the contrast :



A little better, but still hard to tell. From recent use I know to show the grit you have to use/flush the stone. I soak the stone and it starts bubbling, 20 minutes later and it is still bubbling. I take it out and give it a little use and this produces :



Ok, now we can see what is going on as the swarf drops down between the grit. For comparison this is the Bester 700 :



The Suehiro looks like it has large grit maybe but because it seems to be clumped and way closer packed than the Bester, almost like the Sypderco ceramic stones. This is not a good sign for a fast cutting stone (but great for an apex setting stone). A quick check by polishing a 1095 blade and then doing 50 passes :



Really not a good sign for fast cutting, it feels like glass and barely cuts a 1095 Mora. In contrast here is the same thing with the Bester :



A quick check on sharpening the knives I am doing the carpet cutting and the cutting speed is really slow. It behaves almost the exact opposite of the Naniwa Superstone 400 :



Note the Naniwa (left) builds up a mud while the Suehiro just makes a weak suspension and loads. However from previous experience I know that you can't pay much attention to initial uses of waterstones, there is the possibility that some kind of sealer was used, that the binder distribution is uneven and you really need to use it a bit, lap it and see what develops. However at this stage based on how it is reaction I would at least make the following :

-this appears to be a really hard stone
-I don't think it will cut as fast as the Naniwa Superstone 400
-it looks like it will be easy to set the apex

It appears to be a slightly harder and slightly finer Bester 700, now I need to see if this is consistent.

As a final note this is a really inexpensive stone. You could buy 4-6 of them compared to some of the other stones I recently bought.


PB : [s7.photobucket.com]



Edited 1 time(s). Last edit at 09/12/2014 02:50PM by CliffStamp.
Re: Suehiro 'Chemical' stone, #320
September 11, 2014 02:18PM
The interesting thing to me is that it is showing me how little I know about stones. Before I started this I thought I had a decent understanding, I now know that on a scale of 1-5, I am not off of 1 yet.

I tried for example last night to answer a very simple question :

-on a scale of 1-5 how would you rate the hardness of common stones

This really isn't simple which shows a problem as it isn't a complex question. My working idea is :

5 : diamond and CBN plates
4 : the very hard naturals, solid sintered plates (Spyderco)
3 : the very hard "waterstones", possibly this Chemical stone, most oil stones
2 : the medium hard waterstones, softer naturals, Bester, very coarse oil stones
1 : the soft waterstones, very soft naturals; Shapton 120, Superstone 400

However the problem I have with this that the solid sintered plates like the Spyderco are significantly harder than the hard naturals and even the soft oil stones tend to be harder than the harder waterstone. Ideally I would like to use a 1-10 scale but trying to determine that precision is not at all easy.

The only way to do this though is just make the ranking and start filling in stones and learning as you go as the main point of the hard ranking is two things (basically) :

-resistance to gouging, can it be used for very high pressure sharpening
-flattening?

I am going to put up a webpage shortly and possibly a video about this and see if I can get some collective information going.
Re: Suehiro 'Chemical' stone, #320
September 11, 2014 02:33PM
I can totally see why such a rating system would be hard to make.

Thinking about the Naniwa Omura for instance...I would call it soft, same with the King 1K, but maybe I should be more specific and say friable? Because I don't have issues with gouging on either (while I did on the aotoshi), but along the same line both are easy to flatten.

_______________________________________________________________________________________________

Always in search of a good choppa'
Re: Suehiro 'Chemical' stone, #320
September 11, 2014 02:45PM
Yes, there are two issues.

The first is that the properties often used are often combinations of things. For example the Task stone wears fast because it is very friable and the abrasive breaks down. The Shapton 120 wears fast because the binder releases abrasive very easily. Now from a technical viewpoint this is interesting, but most people wanting to get some information don't really care which one is happening just what is the :

-dish resistance or gouging resistance
-rate of wear

The first draft of properties I put together were :


  • Hardness
  • Versatility (with respect to steels)
  • Flattening
  • Clogging
  • Shaping
  • Polish
  • Apex setting

But I didn't like that because the TASK stone is very hard, but it dishes and has low gouge resistance so then I thought well how about using some kind of pressure versatility instead? A lot of these things have to be put into practice and they will evolve as you are doing them as you see what makes sense and is useful.
Re: Suehiro 'Chemical' stone, #320
September 11, 2014 04:09PM
That's why you make a good experimentalist...you enjoy the ride as you look for answers. I get frustrated with the lack of certainty.

At any rate, I guess what I was trying to say is that I don't see dish resistance and gouging as always similar. The Omura for instance dishes relatively easily if working it hard, but I have no worries of gouging it.

_______________________________________________________________________________________________

Always in search of a good choppa'
Re: Suehiro 'Chemical' stone, #320
September 11, 2014 04:31PM
They are slightly different, you can't really gouge the TASK for example, but it will dish very fast. That chinese natural I sent out awhile ago has almost no gouging resistance, you can literally cut it up like soapstone and it wears very fast. I think you nailed the essential difference, a stone with very friable abrasive is very fast wearing but doesn't gouge. A stone with a very weak binder is very easy to gouge. Thus you can have both, none or one or the other.
Re: Suehiro 'Chemical' stone, #320
September 15, 2014 12:34AM
In the first little use this stone :

-was very hard
-did not cut fast
-loaded easily



I had some knives to sharpen which were not in good shape :

-heavily damaged edges, smashed right in flat
-faceted, multiple bevels, high angles

and I need to grind all of that out and form a clean apex at < 10 dps. I decided to use the Suehiro more or less on a lark as it was one of the worst matching stones to what I needed to do and I was in a quirky mood because of an email someone sent on the recent carpet edge retention[*]

--

I started off by soaking the Suehiro for two minutes, grinding for 50 passes with low force (0.5 lbs, 0.5psi) and this was doing little to nothing except loading the surface of the stone. I then did my best Ivan Drago impression, muttered "I will break you." and started ramping up the force and moving the grind down towards the edge so it would do something.

I maxed out at 5 lbs on a 1/8" contact area close to the edge which produced a very high grinding pressure of about 15 psi. At this point the stone basically decided to get the hell out of dodge and just started giving up abrasive. It was like a switch was flipped, it wasn't doing much of anything and then started to do this :



It went from acting far harder than the Bester to being muddier than the Naniwa Superstone 400. All of a sudden Stu's description matched perfectly :

Quote
TFJ
This particular stone is quite 'old school' in the way it works, expending stone material in order to work quickly, so should be considered as 'very soft' and 'extremely muddy', which is preferred by some sharpeners, and does mean that it will not tend to leave significant scratches, making further refinement easier when the appearance of the edge and surrounding surface is important.

At this point I also said to myself "Self, you are pressing way too hard". I scaled the force way down, but even at 1/2 to 1 lbs, which is very light (pressure 1.5 to 3 psi) the stone would do this every 50 pps :



Once it started acting like that then the entire nature of the stone changed. The facets started to faded away on the knife as the stone started cutting much faster and the mud started blending everything together. The stone also took on an extremely odd crunching feel. I am going to have to redo those pictures/checks in the above because the stone doesn't act/cut/grind now like it did in the above at all.

Now here is the interesting part - what happened? There are two common things people warn about with Japanese waterstones :

-they often cover them in a sealer
-the way the make them causes binder to settle to the top

These are both rumors, I have asked but can't get confirmed on either of these, but people do warn that you should really lapp a Japanese stone a few times before you really settle on how it behaves, especially since it has a problem.

My position on this has flopped completely. I really was not that interested in it at all when it was an extremely hard slow cutting stone which could just barely scratch a 1095 Mora, but now it is a very interesting piece of abrasive, especially when you consider it is one of the lowest cost of all the stones I got in that pack.

--



[*] When I started Kyley asked me to include the cKc-X knife, at the end Old Spice noted that a scaled graph would be useful. These two combined produced a graph which showed very strong performance for Kyley's knife. The email (from one of the conspiracy guys on Spyderco's forum) argued that the entire thing had been a setup to promote Kyley's knife in the first place. I don't know if that is sad or funny, so I chose funny and hence made a silly stone selection which turned out to be very interesting. So thank you for your crazy ideas, you contribute in your own unique way.



Edited 2 time(s). Last edit at 09/15/2014 12:37AM by CliffStamp.
Re: Suehiro 'Chemical' stone, #320
September 15, 2014 09:40PM
This is a pretty interesting stone. See that track pattern :



+



This doesn't happen nearly as strong in the Naniwa Superstone 400 which instead forms a very light skim coat of mud, even when the mud gets very thick it doesn't tend to form those very harsh tracks.

--

Now as for the behavior, first the polished Mora/1095 which has a harch scratch as I was not that careful in preventing cross contamination of the Naniwa Aotoshi :



Then a few passes on the Suehiro 'Chemical'



Note the strong difference from the time I tried this early on where it barely cut the surface :




Now do some work to establish a scratch pattern :



as the mud starts to develop it starts to smear out that pattern :



but watch the Naniwa Superstone 400 transform it almost immediately :




It removes those harsh lines and starts giving it that shot peening pattern immediately. Now both of these have a slurry, both are very thick like a mud but they don't behave at all the same even though they are both definitely muddy stone.

Can you tell anything from the slurry, maybe :



That is the Suehiro (the one that makes the coarse scratches) and this is the Naniwa Superstone which gives that shot peening pattern :



It looks like to me what is happening is that the Suehiro Naniwa has a much finer particle size and likely is more free to move around, especially across each other and thus it blends the scratches out. This may be the long lost answer to why some abrasives "grind" and others "polish" as you can see why both of these are removing material they are not at all doing it the same way and it produces very different finishes on both the flats and as well the edge.



Edited 1 time(s). Last edit at 09/15/2014 10:31PM by CliffStamp.
Re: Suehiro 'Chemical' stone, #320
September 16, 2014 12:11AM
From the Naniwa Superstone 400 thread, these are the pass counts for sharpening a very basic stainless steel knife with a few stones under very low applied force (just barely making contact above the weight of the knife) :

  • NoName Stone Coarse : 400, 350, 330 pps
  • Naniwa Superstone 400 : 250, 130, 100 pps
  • Bester 700 : 200, 120, 100 pps
  • Naniwa Aotoshi 2000 : 1000, 550, 700


Same knife, do a few more runs to produce a couple of averages and ranges :

  • Naniwa Superstone 400 : 95 (7) pps
  • Suehiro 'Chemical' 320 : 63 (5) pps

It is obvious the Suehiro is cutting faster, it even feels far more abrasive and remember this is very low pressure as there is barely any force on the stone. Often I am planing down entire primary grinds with stones hence the pass counts are very high (100 to 1000). This is what happens if you are just sharpening and not trying to maintain perfectly consistent geometries for cutting comparisons.

I cut the edge off completely with a pass into the stone (in this case the Naniwa) before sharpening so it is a complete edge reset to clean steel each time, and these passes are very fast, easily 2-3 per second. I could easily put 10 times as much force into these stones and set the bevel almost immediately. In short, completely sharpening a knife should be very fast if you start with a sensible stone.

--


Now there is more to sharpening than just shaping speed, how does this leave the edge? Take in mind that the following pictures are when :

  • there was absolutely NO effort to minimize the burr
  • both are over ground just to make sure the apex was fully formed equally with both stones
  • edge edge bevel is very low, ~5 dps

This is the Naniwa :



and this is the Suehiro :



Note the big piece knocked out of the edge on the Suehiro, again this really is a fairly coarse stone, 320 grit, those big pieces are common along the edge. See as well how some of the scratches are much more coarse than on the Naniwa (the white lines are much thicker).

If you have read the thread so far you might ask about the Naniwa "Hey, where is the shot peening effect you kept posting about?" . As the stone is grinding so fast and I am going so light it really doesn't build up a mud so this is how the abrasive itself cuts without that thick mud coating which smooths everything out.

[



Edited 2 time(s). Last edit at 09/13/2015 03:26AM by CliffStamp.
Re: Suehiro 'Chemical' stone, #320
September 16, 2014 12:17AM
I also just lapped it with that cheap no-name stone I have (2x6" ). I had about 2500 pps on the Suehiro and I mainly just wanted to see how it lapped. The grid lines were removed immediately and the stone was not even visibly uneven before I started anyway. However I have been doing a lot of pattern grinding lately to try to create even stone wear (Murray Carter style) so in general my rate of putting uneven wear on the stones is pretty low compared to what it used to be. However if you are grinding tools and not knives this isn't as easy. I think I need to let some framing carpenters know I sharpen chisels as they beat them up in renovations all the time and knock pieces out of them. Resetting a 1/2" chisel is way more demanding on a stone than sharpening a knife.



Edited 1 time(s). Last edit at 09/16/2014 12:17AM by CliffStamp.
Re: Suehiro 'Chemical' stone, #320
September 16, 2014 10:19AM
I feel silly always just posting good info. But it is, and I really enjoy it.

How much force does it take to get the Naniwa to develop a thick mud?

And I'm surprised the Suehiro was so flat given all the mud it's formed...nice job working the whole stone. Seems like it's shaping up to be a good stone for the price.

_______________________________________________________________________________________________

Always in search of a good choppa'
Re: Suehiro 'Chemical' stone, #320
September 16, 2014 11:43PM
Quote
C Amber

How much force does it take to get the Naniwa to develop a thick mud?

I can't stop it from happening. I just worked the Yanagiba and even with the wide contact area and a pressure of 0.2 to 0.4 psi it still formed. In order to reach that pressure when working on an actual edge bevel you have to be < 1 oz of total force applied, most knives weigh more than that. It is just the way it wears. Now if you don't use water you can stop it from happening as it will just glaze. In fact if you are using it on really cheap knives I would recommend you run it dry and then wet it periodically as it will cut very rapidly on those steels and you don't need constant fresh abrasive as you don't be wearing it down. In that application you use the water to basically let the knife refresh the surface of the stone, like lapping as you are sharpening.

Quote


And I'm surprised the Suehiro was so flat given all the mud it's formed...nice job working the whole stone. Seems like it's shaping up to be a good stone for the price.


Yeah, I have a decent pattern down now, but I don't recommend anyone sharpen the way I do because it keeps slicing the knife towards your wrist. It is very much Carter style except I do it in specific periodic patterns after just observing the natural way the stone wears so this pattern prevents it. I still recommend lapping every 2500-5000 pps just to keep the stone really level as it is so fast and easy then and keeps bevels from getting too much slop in angles.

--


For reference here is the Naniwa Superstone 400 edging 121 REX with the mud :



Note the very strong contrast vs what you get in the above if you don't let the mud build up.
Re: Suehiro 'Chemical' stone, #320
September 18, 2014 12:01AM
Short commentary video, mainly about the dramatic change in behavior :



Re: Suehiro 'Chemical' stone, #320
September 21, 2014 12:09PM
As the Suehiro is faster than the Naniwa Superstone 400 and can be used with more force with less wear I have tried to use it to apex a few knives but the problem is that it will damage the edge fairly easily, far more than the Naniwa Superstone 400.

I have tried a few combinations to see if they can resolve the issue, one combination is the Suehiro 'Chemical' + Naniwa Aotoshi :



This is S30V/Spyderco :

-the blade is starting to take on a high polish (note the solid black)
-however the apex is very irregular and the Aotoshi can't handle it



This is the 121REX/Farid :

-the blade is taking on the high polish but far slower
-the apex damage is even higher

In short, not a huge surprise but the Suehiro 'Chemical' 320 to Naniwa Aotoshi 2000 is too much of a jump and the Suehiro if used to apex high carbide steels is likely to be very wasteful of the steel.

Note those pieces out of the edge are 2-3 times as deep as the damage from a standard carpet run which itself is extremely abrasive/chipping/deforming on the edge.

It seems to be obvious that a next to ideal progression would be :

-Naniwa Superstone 220 -> Naniwa Superstone 400 -> Naniwa Aotoshi
Re: Suehiro 'Chemical' stone, #320
September 22, 2014 02:06PM
To be clear I am speaking in a very specific sharpening niche which is related to the way I sharpen a lot of zero grinds which are prepared for a micro-bevel. I place a lot of value in having a single stone which can both grind enough material to do this fast enough and still apex cleanly so as to not undermine the performance of the micro-bevel AND do this over a wide range of steels. If these things are not important to you then stone selections differ.

I think I am going to revist the SPS series shortly especially as I have the mid range one of them as I think this might be a more suitable set of stones but they are costly and they are niche designed.



Edited 1 time(s). Last edit at 03/28/2015 10:42PM by CliffStamp.
Re: Suehiro 'Chemical' stone, #320
September 24, 2014 11:10PM
I have been doing a bit more work with this and you can easily control how the stone behaves in regards to it being muddy or not. If you use it as a splash and go it will be much "harder" meaning the abrasive will not release, the stone just wears and it is very nice to sharpen. If you soak it then it becomes much "softer" meaning the abrasive will easily release, it builds up a thick mud and it grinds much faster. If you try to run it dry on very hard/high carbide steels it gets slick and will even load. It is very similar to the Bester but even more extreme in behavior.

This can be varied a bit more but running the stone a little dry but using a coarse slurry additive (some silicon carbide loose grit) and if you time this right with the right amount of wetting you can get a stone to cut fast initially but then get to the different state which is easier to sharpen with. However it takes a bit of work to get the right mixes and it is simpler to just use it to shape your knives and then let it dry out and then use it splash and go to set the apex.

It is interesting how this stone can go from being very useful to being almost useless if you don't get the pressure/wetting right. In some ways waterstones are much more finicky than the old style oil-naturals and the diamond plates (which can be fragile however).
Re: Suehiro 'Chemical' stone, #320
September 29, 2014 09:22PM
As an update, you really don't want to leave this stone soaking in water.

--

On Sunday I was working with knives off and on much of the day so the stone never really dried out and I had it sharpening again. I would basically soak it for 5 minutes, do about 500-1000 pps with it and then repeat this 1-2 hours later. At the end of the day I went to lap it :



See all those pieces, those are from the Suehiro. When the stone I was using to lap hit the corners it would just knock off large pieces and the Suehiro itself felt like very soft chalk, almost mushy.



The slightest pressure at the edges and they would just crumble away.



Edited 1 time(s). Last edit at 09/29/2014 09:24PM by CliffStamp.
Re: Suehiro 'Chemical' stone, #320
October 04, 2014 01:30PM
As a few updates, I have been playing with using drywall mesh as a stone flattener. This is 80 grit Gator and it is $1/sheet :



It is MUCH faster than the cheap stone I normally use which will take 25-50 passes, this takes just 10-15. However it is shedding grit fairly fast so I don't know how long it will last. But if you are not doing a lot of sharpening it may be a practical solution and it is double sided.

--

I have also slightly refined my sharpening technique a little. I used to be very focused in the sharpening stage to bringing the edge to an apex, however I have backed off that recently which allows me to use more coarse stones which provides faster shaping without damaging the apex.

The trick is to stop ideally just before you apex. This is the edge on a VG-10 Lum at 6.5 dps which was shaped with the Suehiro 'Chemical'. Note that there is still a hint of the last micro-bevel at the apex which isn't completely removed :



I can then finish it on the Naniwa Superstone 400, or to really take it to the limit, the Naniwa Atoshi 2000 before the microbevel :



As the apex isn't fully formed in the shaping any more it can take more passes on the micro-beveling stage. This used to be 5-10 pps at most, however it can now be 30-40. But an additional 25 pps here is worth saving 200-400 pps in the shaping.

The downside of the multi-stone approach is of course you have to keep flattened all three, whereas before I was playing with just using one stone for the shaping and by altering the water/mud formation, getting a finer apex by adjusting the stone cutting speed/coarseness.

I started doing this just to have more stones to flatten as I want to see how long some very coarse papers last as flattening agents, but it seems like it might be useful directly especially if you are using multiple stones anyway.
Re: Suehiro 'Chemical' stone, #320
October 06, 2014 04:43AM
Quote

I have also slightly refined my sharpening technique a little. I used to be very focused in the sharpening stage to bringing the edge to an apex, however I have backed off that recently which allows me to use more coarse stones which provides faster shaping without damaging the apex.

The new method is to stop shaping before you apex, and then apex in the microbevelling stage? Can you still see some light reflecting when you stop the shaping?

Quote

I can then finish it on the Naniwa Superstone 400, or to really take it to the limit, the Naniwa Atoshi 2000 before the microbevel :

By "finish" do you mean apply the microbevel or do you mean continue shaping at the original angle until the apex is reached, only on a finer stone (I assume the former)? Is the picture following this quote of the edge after microbevelling on the aotoshi? That's what it looks like and would make more sense if I'm understanding you're new method...

How detrimental is it to apex on really coarse stones? I always do because I'm too impatient to shape on finer stones, especially working the thick bevels on friends pocket knives.
Re: Suehiro 'Chemical' stone, #320
October 06, 2014 10:01AM
I'm glad you asked about this Ian, as I wasn't sure either.

Quote
ianevans
The new method is to stop shaping before you apex, and then apex in the microbevelling stage? Can you still see some light reflecting when you stop the shaping?

If he hasn't apexed it yet you can still see some light reflecting, but it will be at it's minimum at this point...doing any more work would completely apex it and remove the light.

Quote

By "finish" do you mean apply the microbevel or do you mean continue shaping at the original angle until the apex is reached, only on a finer stone (I assume the former)? Is the picture following this quote of the edge after microbevelling on the aotoshi? That's what it looks like and would make more sense if I'm understanding you're new method...

How detrimental is it to apex on really coarse stones? I always do because I'm too impatient to shape on finer stones, especially working the thick bevels on friends pocket knives.

This is the part I was unsure of, but I believe you have interpreted it right. I think he means to continue to shape at the original angle until the apex is reached with the Naniwa 400 or Aotoshi 2000+. The 400 (as can be seen in some of the previous pics) actually produces a really fine finish because of it's mud, and so sets up the edge perfectly for the microbevel (again this can be seen in previous posts). It's very smooth and even along the apex.

Which brings me to your point about apexing on coarse stones. If your goal is not a coarse edge for cutting soft materials that benefit from a jagged edge, it is often detrimental. You have to consider the grit size on a coarse stone and think that if you take it all the way to the edge, there will be portions of the apex that are very jagged where the grit simply ripped out pieces of it. You can microbevel over this, but it doesn't remove the jagged peaks (think microbeveling over serrations...yeah the very apex where you hit it is finer but it still has a jagged profile). This leaves the edge "weaker" as if you hadn't microbeveled for chopping applications (stress points from the jagged areas) or less than idea for push cutting (no uniform bevel).

The solution is
1. to work your way up in grits smoothing out the apex
2 use waterstones and hone to dry...let the stone dry out as you apex becuase it will not cut as well and the scratch marks will get smaller and the apex will get smoother and more "polished"
3. use a coarse stone like the Naniwa 400 that develops a thick mud and use less pressure as you begin to apex and let the mud with it's broken down grit refine the apex. This doesn't work with all stones though...see the Suehiro 320 whose mud behaves differently...it still helps w refining the apex and not leaving it as jagged, but it doesn't do it to the ideal level.

_______________________________________________________________________________________________

Always in search of a good choppa'
Re: Suehiro 'Chemical' stone, #320
October 06, 2014 11:53AM
Quote
ianevans
Can you still see some light reflecting when you stop the shaping?

Yes, in certain parts of the blade. To be clear all I am doing here is trying to optimize two things at the same time which are directly opposite each other in certain respects, hence the complication :

-steel wasted in sharpening
-time

This is amplified by the fact I am usually working on very low edge angles, often on full zero-grind.

If I take the edge completely to an apex it means part of it will be over ground as you will never get it to a uniform apex because the edge will wear and grind at different amounts.

As I am always going to micro-bevel, the shaping is just a prep for this step. In the past I apexed in the shaping under the thought to minimize the amount of micro-bevel work.

However lately I have looked at doing a little more work int he micro-beveling to see if I can reduce/simplify the shaping.

Quote

By "finish" do you mean apply the microbevel or do you mean continue shaping at the original angle until the apex is reached, only on a finer stone (I assume the former)?

I was not very clear here, I meant that if you want you can return to do a full shaping to an apex with a finer stone if you want however I am finding that it isn't strictly necessary and isn't compromising the performance.

Quote

How detrimental is it to apex on really coarse stones?

Take a look at the Maxamet thread to see what happens if you take < 100 grit stones to a ~5 dps edge and bring it to an apex.



Edited 1 time(s). Last edit at 10/06/2014 01:00PM by CliffStamp.
Re: Suehiro 'Chemical' stone, #320
October 06, 2014 01:06PM
I should add however that this isn't something you should play around with unless you are very familiar with sharpening because it can easily lead to frustration. If you don't bring the knife fully to an apex then the micro-bevel could have so much steel to remove it will lead to issues with excess burr formation or simply being impossible to do.

For example I have shown how you can jump right form the CBN rods on the sharpmaker at 15 dps to a micro-bevel on the fine rods at 20 dps. In order to do this you need the apex very close to fully formed or else the fine rods simply will never sharpen it because they can't remove significant amounts of material.

These are just experiments trying to refine the techniques, optimize various factors and of course keep it interesting for me as I sharpen a lot of knives daily and this allows me to learn/experiment with even the mundane parts of it.

--

If you just want a practical approach there are better ways :

-apex on a very coarse stone
-increase the dps, micro-bevel

If there is a very large jump between these you will end up with a grit finish between the two, this may or may not be a bad thing, it just depends on what you are trying to achieve. For example when Spyderco sharpened the 10V/K2 this is what they did :

-very coarse belt
-high polish buffer

and it left some of the coarseness of the belt remaining for an aggressive slicing edge. It approximates well a grit in between the belt/buffer and you can move the point by just doing more/less buffer passes (and varying the buffer grit as well).
Re: Suehiro 'Chemical' stone, #320
October 06, 2014 03:46PM
Quote
CliffStamp
To be clear all I am doing here is trying to optimize two things at the same time which are directly opposite each other in certain respects, hence the complication :

-steel wasted in sharpening
-time

Yea, and I usually just care about the time part when sharpening for others since I typically have to hog off a bunch of steel to get to something undamaged that will take a good edge. I recently had to sharpen and re profile a friends skinner six times before a stable edge would form... And even then, I had to perform the deburring step four times on the coarse stone before microbevelling on a finer stone.

On my own knives, I'll play around with apexing on a finer stone (likely shapton glass 1000) and then microbevelling on my usual finishing stone (fine side of Norton economy stone) and see if I notice any improvement in edge retention or sharpness. If I do, then I'll see about stopping shaping a bit before apexing and then spending more time on the microbevel.

Ultimately, it probably won't be worth it from a time perspective since I usually sharpen my own knives on a jig system like me2's blocks and the alternating passes of microbevelling are the slowest part of sharpening, since I have to flip the jig around each pass. The practical approach you mention of apexing on a coarse stone and then microbevelling on a fine is what I normally do and it is very fast and reliable... I cobbled it together from your videos and reading stuff here a year ago and it revolutionized my sharpening.
Re: Suehiro 'Chemical' stone, #320
October 06, 2014 03:55PM
Quote

Which brings me to your point about apexing on coarse stones. If your goal is not a coarse edge for cutting soft materials that benefit from a jagged edge, it is often detrimental. You have to consider the grit size on a coarse stone and think that if you take it all the way to the edge, there will be portions of the apex that are very jagged where the grit simply ripped out pieces of it. You can microbevel over this, but it doesn't remove the jagged peaks (think microbeveling over serrations...yeah the very apex where you hit it is finer but it still has a jagged profile). This leaves the edge "weaker" as if you hadn't microbeveled for chopping applications (stress points from the jagged areas) or less than idea for push cutting (no uniform bevel).

Makes perfect sense. For most knives I sharpen, the fairly jagged slicing edge is fine, but my kitchen knives could benefit from some greater push cutting ability. I used to do them like this... Burr sharpening and moving up the grits with no microbevelling and I could achieve things like push cutting tomatoes or slicing grapes without holding them, but I'd spend 45 minutes to an hour on a knife. Now I spend five minutes and the knife performs fine, it's just not as silky when you're, say, chopping onions. I need to play around with finding a happy medium.
Re: Suehiro 'Chemical' stone, #320
October 06, 2014 10:06PM
As a point of comparison to the above :




look at this :



This is the Suehiro on the Paramilitary/S30V taken to an apex fully at 6.5 DPS. I then polished it on a Naniwa Aotoshi 2k just to highlight the edge that is why it all looks so black. It should be obvious that if you don't want the apex at that very low grit then it isn't ideal to apex it because of the work you will have to do to get rid of it.
Re: Suehiro 'Chemical' stone, #320
October 11, 2014 11:11AM
A few updates :


I left this in the water over night to check long term soaking. With many modern stones this is a big risk as they can crack or over soak and damage the bond permanently, you are heavily warned for example to not do this with all splash and go stones. However I was still having issues with the Suehiro needing to be constantly wetted during sharpening and quite frankly I was just curious. What happened? Nothing really aside from it solving the constant wetting problem. Now frankly it likely doesn't take 24 hours to saturated, it is more likely 30 to 60 minutes would do it fully.

However as noted in the above you could get issues with lapping with the corners when it is heavily soaked so I would let it dry out before flattening. I am really curious however if I can get that to happen again as I never saw a stone disintegrate like that before so I might over soak it again at some point to see if I can make it crumble.

As a final point in regards to this being a soft/muddy stone vs a hard one it really depends on the steel. If you use this on 3Cr13 type steels the stone digs into them heavily and that causes a lot of grit tear out and heavy mud. If you use steels like VG-10/S30V (and above) the stone tends to just wear even when you use high forces. Now you can make it a muddy type stone on those steels, all you have to do is start the mud and it will keep generating itself. The simplest way to do it is get it going by sharpening a very low carbide steel first, if you don't have one that needs it just use a very small amount of lapping compound. A little dot of 90X Silicon Carbide, half the size of a pencil top eraser, easily cuts up the stone (and steel on the knife) enough to get that slurry/mud developed.
Re: Suehiro 'Chemical' stone, #320
October 11, 2014 06:28PM
I tried this on the 10V K2/Farid, the stone will cut/sharpen it, but the stone is fairly slick and it is not at all easy to tell if you are sharpening on or below the bevel because it doesn't cut that type of steel (at that hardness) very aggressively.
Re: Suehiro 'Chemical' stone, #320
October 24, 2014 12:52AM
I am doing an edge retention run on this now, interestingly enough I would much rather sharpen the EveryDay Essentials on the dressing stone than this knife : [www.cliffstamp.com] .

The dressing stone procedure is as basic as this :

-grind fairly hard to form an apex, usually results in a significant burr
-rinse off the stone with a quick spray
-elevate to 15 dps, 5-10 light passes to form a micro-bevel

That is pretty much it, it can't be more basic. However this is the Suehiro :

-form an apex, very little burr (much better than the dressing stone at this point)

Now the fun begins :

-use the dressing stone (or something) to clean/lapp the surface
-rinse well
-let dry until a pass doesn't form a swarf
-carefully form an apex using all the burr minimization techniques

One the first try I still only got it 75% as sharp as the dressing stone in about 5X as much time.
Re: Suehiro 'Chemical' stone, #320
October 25, 2014 12:52AM
I did another run with this, it isn't a pleasant knife to sharpen with but I don't think I am doing it the most efficient way. The problem is that when you apex at the edge angle of ~5-6 dps it will damage the edge with the force/speed I am using. The micro-bevel doesn't remove this damage well and thus the sharpness will not easily get past about 35%. It can shave, do a push cut on light exercise paper, but this sharpness is absolutely trivial to more than double with a DMT plate.

I think however I know a much better way to approach it which is to work up a thick mud on the stone as this should be able to apex the edge without the damage that can result from the coarse grit and then clean the stone to apex without trying to remove the damage at the same time. Now of course this would be trivial if I just apexed on the Naniwa Superstone 400 and then just micro-beveled on the Suehiro however that kind of defeats the point of the exercise.
Re: Suehiro 'Chemical' stone, #320
October 25, 2014 01:16AM
A bit of playing around and I can hit 50% but not consistently, the problem is that this is a pretty soft stone and easily releases abrasive which is coarse and will roll around in the mud and hit the edge so it is pretty easy to get spots which are damaged when you set the apex at the ~6 dps stage. The refinement isn't trivial because the stone doesn't cut really well with ultra-light force when you have it wear so unevenly. Now I could easily resolve this by :

-doing the initial shaping at ~6 dps with a heavy mud which is worked fine
-lap the stone with a much finer stone to even it out and micro-bevel with that

But that procedure really isn't what I am thinking about with this edge retention comparison of different grits on hemp as I am trying to keep it as close to how you would naturally sharpen on the stone itself not any additives.