Tested: Venev F1200 (100%) versus CGSW 5 micron

[3D Anvil]

Background: I've had the CGSW 4" stones for KME for about 6 months and just recently got a set of the Venev 6" Orion stones to complement my new Hapstone system. The Venev set I got has 100% diamond concentration, which may account for the difference in the results discussed below. According to Gritomatic, the 25% concentration stones show fewer fine scratches.

Anyway, my subjective impression from using both sets was that the CGSW 5 micron stone produced a glassier, more mirrored finish than the Venev F1200 stone. To test the theory, I sharpened both sides of a beater knife using the Venev stones up to the F800 grit. Then I sharpened the show side of the blade using the CGSW 5 micron stone and the lock side with the Venev F1200 and compared the results. To be as fair as possible, I only used 4" of the Venev stone.

The contestants:







You can see in the last pic that the Venev stone
has a much thicker diamond layer (3mm vs. 1mm), while the CGSW stone has a much thicker aluminum blank.

And this is what their respective finishes look like under my el-cheapo USB microscope. I tried to capture the finishes as best I could:

Venev:


And CGSW:


And finally, I tried -- without a lot of success -- to capture the finishes on video:

To me, the clear winner between the CGSW 5 micron and the Venev 100% concentration F1200 is the CGSW, based solely on the quality of the finishes they produce. I also think the CGSW stone has better diamond layer uniformity and flatness -- the latter probably due to the CGSW's much thicker aluminum blank. On the other hand, the Venev stones stay wet longer and thus require less interruption to keep the stones lubricated. And of course the Orion series' diamond laye is 3x thicker than CGSW's.

That's all, folks!

 

[777 Edge]

Great comparison 3D Anvil !

The GCSW stones load up and glaze a lot faster than the Venev stones does, which could be what is making the difference you're seeing. Your scratch pattern with the 5 micron CGSW stone should show more scratch marks (being 5 micron-sized diamonds), if I compare it to what I've seen with the CGSW 5 micron when refreshed.

Also, FYI the CGSW stones (when new) have a thick layer of resin/epoxy that has settled on the top layer of the stone and it makes the stone very, very glassy (it needs to be removed before use. A Nagura or quick condition with SIC on a flat surface does a great job of this). If there is any of this top layer of resin / epoxy left on the CGSW stone, the stone does not cut like it should at all.

For interest sake, do you mind polishing the bevel to a complete mirror on both sides of your knife (whichever way you can do to achieve a good and even mirror on both sides first). Then take a Nagura stone (or SIC if you like) and condition / refresh both the CGSW and Venev stones with it to produce a completely fresh, unglazed & unloaded surface on the stones, and then dropping back down to create a new scratch patten on each side of the bevel to compare the 2 stones again?

I'd be keen to find out what your results are.

 

[777 Edge]

I ran a quick scratch pattern test on my CGSW 5 micron KME size and my Venev Scorpion series 1200 grit KME size stones. Both stones were refreshed before use with a King Nagura 8K to ensure they both have fresh and conditioned surfaces.

The scratch pattern from the CGSW is very, very marginally better (hardly noticeable), but both are incredibly similar.

For the microscope pics, I tried to get the light to reflect on the scratches specifically (not on the polished mirror of the edge). Both are just for a quick scratch pattern test as a comparison. As seen wit the naked eye, both are near mirror polishes with very barely noticeable visible scratches.

Note, in the pics below I did not properly sharpen for edge quality comparison, only for scratch pattern comparison.

Venev Scorpion 1200 grit below:




CGSW 5 micron below:

 

[3D Anvil]

I ran a quick scratch pattern test on my CGSW 5 micron KME size and my Venev Scorpion series 1200 grit KME size stones. Both stones were refreshed before use with a King Nagura 8K to ensure they both have fresh and conditioned surfaces.

The scratch pattern from the CGSW is very, very marginally better (hardly noticeable), but both are incredibly similar.

Is the Scorpion series the one with 25% diamond concentration?

 

[777 Edge]

Is the Scorpion series the one with 25% diamond concentration?

No, mine are all 100% concentration stones. The Scorpion series is the KME form factor & size.

 

[3D Anvil]

No, mine are all 100% concentration stones. The Scorpion series is the KME form factor & size.

Interesting. I wonder what accounts for the different results? I suppose it's possible that the newness of my Venev's relative to my CGSWs could be a factor. The exposed diamonds could be sharper.

 

[777 Edge]

Interesting. I wonder what accounts for the different results? I suppose it's possible that the newness of my Venev's relative to my CGSWs could be a factor. The exposed diamonds could be sharper.

Yes, it is interesting. I made sure to refresh both mine before my test. My only guess would be that your CGSW 5 micron needs a refreshed surface for a good and equal comparison.

After both your stones have been refreshed / conditioned, please give it a try again with a fresh stone surface. I'm really curious to see what you find!

 

[Diemaker]

Keep in mind that after dressing, the CGSW stones are abnormally coarse and need about 40-50 passes on a knife to break in. This may explain the difference the two of you are seeing in the scratch patterns of my 5 micron stones.

3D Anvil, how do you dress your 5 micron stone? I suggest 240 grit Alox but I have used 5 micron and it still worked fine, but would take forever to dress it for the first time. Whether the abrasive is black Sic or brown Alox doesn't matter, only the grit matters. I say black or brown as those are the least friable forms of those abrasives so they resist breaking down the most.

I forgot to say that for the best comparison between the stones you should do the full sharpening with either set, not just end with the two different stones.

 

[3D Anvil]

Keep in mind that after dressing, the CGSW stones are abnormally coarse and need about 40-50 passes on a knife to break in. This may explain the difference the two of you are seeing in the scratch patterns of my 5 micron stones.

3D Anvil, how do you dress your 5 micron stone? I suggest 240 grit Alox but I have used 5 micron and it still worked fine, but would take forever to dress it for the first time. Whether the abrasive is black Sic or brown Alox doesn't matter, only the grit matters. I say black or brown as those are the least friable forms of those abrasives so they resist breaking down the most.

I forgot to say that for the best comparison between the stones you should do the full sharpening with either set, not just end with the two different stones.

I used 240 grit sic powder, so that should be good. I'd also sharpened around 10 knives on the Venevs before the test, so that would suggest to me that break-in wasn't a huge deal.

 

[777 Edge]

Keep in mind that after dressing, the CGSW stones are abnormally coarse and need about 40-50 passes on a knife to break in. This may explain the difference the two of you are seeing in the scratch patterns of my 5 micron stones.

Good point D Diemaker but I don't think we can really use a well used or broken in stone as a comparison. We should be comparing apples with apples and can only do this with a fresh stone surface. The only true comparison would be a completely fresh stone surface.

The Venevs glaze up less and release bond more readily than the CGSW stones, thus the surface stays aggressive much longer on the Venev stones.

The size and consistency of the diamonds is what does the cutting, not the bond, but the bond can cause the stone to significantly "underperform" when glazed or loaded, and this happens more with the CGSW bond than the Venev bond.

Don't get me wrong, I absolutely LOVE your CGSW stones and they are some of my all-time favourites.

 

[Diemaker]

The problem I have with your comparison is you are using my stones as I didn't intend them to be used, so it is not a fair comparison IMO. When they are freshly dressed they only screw up the bevel with too many scratches, they need to be broken in to work properly. If that is how you like them to cut then drop down a grit and you get the same effect without over dressing them. My stones wear from dressing, not so much from use as long as you don't let the swarf build up. Swarf acts just like the lose abrasive used to dress them, so it definitely increases the wear rate.

What do you consider "glazed"? With my 5 micron stone I get 40-60 knives sharpened before I feel the desire to clean them up beyond a thumb scrub. The coarser the stone the longer between cleaning/dressing. Sure they get rather dark but still only take 3-4 passes per inch of blade to remove the scratches from the previous stone.

 

[777 Edge]

Fair point D Diemaker , but for a good comparison of any sharpening stone with another one, they need to have a fresh surface. If not, it's like starting a quarter mile race with 1 car halfway down the track and the other at the starting point, or 1 car with warmed up tires and the other with cold ones.

I don't refresh my stones that often, but if you want to compare stones directly you simply cannot compare 1 stone that's been well used with another stone that has a clean and fresh surface. They both need to have a fresh surface for a fair comparison.

Any stone with a hard bond will cut metal smoother and smoother as time goes by. If you have a stone with a softer bond, it cuts more like it did when it was refreshed because the bond is softer. So, how can we have a repeatable start point for direct comparison?

If we start comparing this way, every stone manufacturer would have to have a guide saying "My AA stone needs to be used for xx strokes before it's just right, my BB stone needs yy strokes before it's ready for use, but the CC stone cuts the same at zz strokes, as it does at yy strokes." Now, that's all fair game for guys who have borderline sharpening OCD like some of us here, but for the average Joe who likes to use clean stones and just wants to experiment with getting a knife really sharp with 1 stone vs another or who wants to mix up stones from different manufacturers and grits with their sharpening progression...How would they Ever have a place to start comparison?

Due to different rates of glazing and wear with different bonds in different stones, performance changes more than others over time, so how on earth would we ever have an equal start point to compare stones, if we don't actually start at the same point?

And again, don't get me wrong, I'm not trying to make your CGSW stones out to be worse or better than other ones (because they ARE some of the best stones available), I'm just saying that we can't realistically compare similar stones if we don't have consistent parameters.

I also have to add another big compliment regarding your CGSW stones - the diamond loading and particle size is the most consistent and tightly controlled with any diamond bonded stone that I've used, and the tolerances and quality of manufacturing is heads and shoulders above most.

 

[777 Edge]

Let's open up a can of worms and scratch the itch of knowing what both would look like after they've been used for a while, so I ran another test. Pics below.

Firstly, let me say that BOTH of these edges managed to cut and split a human hair directly after finishing with these stones, without any stropping at all.

Here is what I did: I refreshed and conditioned both CGSW 5 micron and Venev 1200 again. Then I used both stones for about 100-200 stokes before taking some more photos to compare how they did after the same amount of "breaking in" use.

As expected, the scratch pattern refined more after both stones were used for a while. But what surprised me was how the Venev 1200 actually started to outperform the CGSW stone. I expected the CGSW stone to outperform the Venev after 100-200 strokes, but actually found just the opposite. Again, I am figuratively and literally "splitting hairs" here with this comparison because both of these stones produce an immaculate edge, both of almost exactly the same quality, so in reality it's "potayto" vs "potaato". Both are incredible stones.

CGSW after 100+ strokes below:




Venev 1200 after 100+ strokes below:

 

[3D Anvil]

That's very interesting, and not what I would have expected either.

As an aside, I'm mystified about how you guys get hair splitting edges straight off the stone. I think I'm doing everything right -- apexing the edge, going through the progression of stones, finishing with edge leading strokes to debur (4 per side, then 3, 2, 1) ... and I get a mirror(ish) edge, but when I test right off the stones I end up with a score of around 140 BESS before stropping, which is sharp, but a long ways from hair popping. Any advice?

 

[777 Edge]

Sounds like you're doing everything right, so all I could really say is to do very light full stone length strokes, especially towards the end. Always let the stones do the cutting, not with any force at all or you'll deflect the edge away from the stone and miss the apex - or worst-case, damage the apex.

I've never been in the camp of specific or crude deburring as such. My whole sharpening session is geared towards burr minimization - after it is initially formed.

Here is roughly what I do: I start with forming a burr each side, then minimize it with very light leading edge full stone strokes in one directional pattern on both sides of the knife, after which I move up to the next stone to remove the scratch pattern of the previous grit and then do the same burr minimization as before. And I do this with every grit of stone throughout my progression.

Also, I'm not in any of the camps of sharpening only in one direction. Before my final few leading edge strokes on each stone grit, I sharpen both ways (leading and trailing) in a uniform pattern. It's fairly basic in my opinion - just remove metal with each stone in both directions until the final step, then I do edge leading light strokes.

And lastly of course, some steels take on a hair slicing edge quicker and easier than others.

 

[3D Anvil]

Yep, that sounds like what I'm doing. One thing might be the final strokes I'm doing. I do the deburring strokes into the edge, but I typically do full-length, sweeping strokes from the heel to the tip. I wonder if maybe that's messing up the scratch pattern and thus the apex....? I'll try it with more perpendicular strokes next time.

While you're here ... I got a notification that that CBN 120 stone you mentioned is back in stock. But it's $220! Is it really that much better than the Venev F80 for bevel setting?

 

[Diemaker]

777 Edge, your latest results look off to me, but since you don't use my stones as I suggest that may explain why they are not performing as I would expect. My finer stones perform far better using only edge trailing passes vs any edge leading passes. I have ordered my own set of Orions and will respond after I have a chance to use them myself.

 

[777 Edge]

777 Edge, your latest results look off to me, but since you don't use my stones as I suggest that may explain why they are not performing as I would expect. My finer stones perform far better using only edge trailing passes vs any edge leading passes. I have ordered my own set of Orions and will respond after I have a chance to use them myself.

D Diemaker , the results and performance can't get much better than slicing hair straight off of your 5 micron CGSW stones. I would personally call that fairly good results, no? Perhaps you missed that part in my post above.

I'm not sure what you mean by "looks off"? Please elaborate.

Yes, I know you recommend a certain method of sharpening (edge trailing only). I don't doubt that it works well for your own personal method & pressure of sharpening and yields good results for you personally, but with the right pressure and sharpening method the end result is near perfect with edge leading final strokes also. This applies to your stones, and for the Venevs.

I'm not saying edge trailing is wrong, if it works for someone's style and method then by all means go for it. But if done correctly, then edge leading finishing on a high quality fine stone works just as well, or even better.

Your method of doing a whole session of sharpening (beginning to end on each stone) by using edge trailing strokes only, will wear down stones much slower but sharpening also takes much longer if you're doing hundreds of knives a week. Burr formation with edge trailing strokes alone can also cause issues with some types of knife steel. YMMV, but with my own style of sharpening it works perfectly well and yields excellent results.

 

[777 Edge]

While you're here ... I got a notification that that CBN 120 stone you mentioned is back in stock. But it's $220! Is it really that much better than the Venev F80 for bevel setting?

The composition, loading and grit size of the metallic CBN 120 just seem to be a winning recipe for removing metal faster than most stones, but if you're not re-profiling a lot of knives regularly then there is no specific need to have one.