Do I need a polishing stone?

[kayman67]

Which 15k stone did you use? One doesn't hear of those too often.

Shapton Pro 12 was 15 in the past, as said above. 2:1 stone
There are some 15-16k stones out there. Not a very usual grit, though.

Anyway, higher grits are about skill before the grits themselves. Some stones might make it easier, some not so much. This doesn't make them better as in best possible results, but some results are better than no results or worse. And at some point you choose even without knowing. I do like some stones better than others, but that might be just me.
One of the most unusual combos is the Sigma 1200 + 13000. Seems so unreasonable to make such a huge jump and for some purposes it is, but for some reason, the 13k really improves edge retention even with more demanding alloys (like ZDP-189 or HAP40). I was quite amazed especially with ZDP-189. I always wondered how such a combo came into existence (since Sigma has 6000 and 10000 that would have been a more convenient choice maybe).

So I am going to respectfully disagree with you on that, coming just from an engineering point of view. When you have a “ toothy” edge you have a more structured edge, meaning the highs and lows of your grind add a structural rigidity to your edge it will last longer but may not get quite as sharp. When you go to a higher grit and start removing that structure you lose edge retention, for me that is just straight up engineering and geometry.

Not really true. Was proven already that micro fractures at apex level will dull the edge faster (even maintenance involved). There is something that concerned some alloys where the structure is so much more resilient, that would actually benefit, but rarely, if at all, common with kitchen knives.

 

[M1k3]

Shapton Pro 12 was 15 in the past, as said above. 2:1 stone
There are some 15-16k stones out there. Not a very usual grit, though.

Anyway, higher grits are about skill before the grits themselves. Some stones might make it easier, some not so much. This doesn't make them better as in best possible results, but some results are better than no results or worse. And at some point you choose even without knowing. I do like some stones better than others, but that might be just me.
One of the most unusual combos is the Sigma 1200 + 13000. Seems so unreasonable to make such a huge jump and for some purposes it is, but for some reason, the 13k really improves edge retention even with more demanding alloys (like ZDP-189 or HAP40). I was quite amazed especially with ZDP-189. I always wondered how such a combo came into existence (since Sigma has 6000 and 10000 that would have been a more convenient choice maybe).



Not really true. Was proven already that micro fractures at apex level will dull the edge faster (even maintenance involved). There is something that concerned some alloys where the structure is so much more resilient, that would actually benefit, but rarely, if at all, common with kitchen knives.

Is the Sigma 13k one of the SiC stones? I've heard a few if them are SiC, the rest AlOx?

 

[inferno]

as far as i know only the green 240 and the black 1k are SiC.

stefan wolf on the tube has a few high grit sic stones. look it up on youtube. but they appear to be tool stones.

 

[kayman67]

1000 is also SiC. I'm not entirely sure about 1200, but it's really fast with ZDP-189.

 

[kayman67]

1200 seems to be Aluminum Oxide, but Jende says it removes matrix steel and carbides. That's pretty much like coarse SiC behaviour and would explain why I found it to be so efficient.

 

[inferno]

a 1k stone is so coarse and if the binder behaves in a certain way and the abrasives are shaped a certain way i guess it could scoop out lots of steel even if its an alox stone. i guess a good 1k is a good 1k no matter what steel and what abrasive is used.
i really haven't found a 1k yet that was really slow even on high alloyed steel.

 

[kayman67]

The most interesting 1000 stone I came across, was from Chroma a few years ago. I don't know who made it as no other manufacturer I tried had something similar. This was a soaking stone, very very hard, very very fast, but also had the feedback of a much finer stone (more like Chosera 3000).

Sigma 1000 looked to me as being SiC. Searching a bit, looks like it is.

 

[zizirex]

The most interesting 1000 stone I came across, was from Chroma a few years ago. I don't know who made it as no other manufacturer I tried had something similar. This was a soaking stone, very very hard, very very fast, but also had the feedback of a much finer stone (more like Chosera 3000).

Sigma 1000 looked to me as being SiC. Searching a bit, looks like it is.

i thought it's just rebranded (New) Cerax 1000?

 

[kayman67]

I don't really know. They sold lots of stones and changed them. My Suehiro 1000 is definitely different, although both soaking stones.

 

[inferno]

another good soaker very hard stone(s) - juuma 800 and 1200.

 

[kayman67]

I want one. Never got to it yet.

 

[zizirex]

Shapton Pro 12 was 15 in the past, as said above. 2:1 stone
There are some 15-16k stones out there. Not a very usual grit, though.

Anyway, higher grits are about skill before the grits themselves. Some stones might make it easier, some not so much. This doesn't make them better as in best possible results, but some results are better than no results or worse. And at some point you choose even without knowing. I do like some stones better than others, but that might be just me.
One of the most unusual combos is the Sigma 1200 + 13000. Seems so unreasonable to make such a huge jump and for some purposes it is, but for some reason, the 13k really improves edge retention even with more demanding alloys (like ZDP-189 or HAP40). I was quite amazed especially with ZDP-189. I always wondered how such a combo came into existence (since Sigma has 6000 and 10000 that would have been a more convenient choice maybe).

Have you tried the Sigma 13K? any comparison with other ultra-fine grit stone?

 

[kayman67]

Any particular stone in mind?

 

[zizirex]

Shapton Pro 12k or Shapton Glass 16k, maybe naniwa Ss 12k?
Im choosing between shapton and sigma

 

[kayman67]

These types of comparisons might be a bit tricky, but I will consider the same knives.

To start with, Sigma needs some water. Way less than Sigma 10k, but the others don't really need any.

Sigma offers pretty much the same level of performance and couldn't care less about surface maintenance, while the others are a lot more problematic (Naniwa Super Stone 12k and Shapton Glass 16k in particular).

Sigma has the brighter finish (with some shirogami as common reference), while Shapton Pro 12k might be the opposite.
Sigma has the best scratch management I've seen. Takes care of most scratches and always delivers a bright polish. Very consistent behaviour. With some more contrast available, this would have been a crazy finisher.

 

[zizirex]

I see, so contrast is much better on Sigma? And brighter mirror polish? How thirsty is the Sigma? Do I need to soak it or just a little bit of running water is fine? Edge quality and speed is very similar I’m guessing?

 

[kayman67]

There is a decent amount of contrast. More like very bright (mirror) and less bright (haze) combo. But it's not the contrast I get from Jnats.
Under running water is just fine, for about a minute. No soaking. Requires little after. With Sigma 10k I would have to soak it for some time and also use more water.
Delivers very sharp edges, but might need some care with burr development, I guess. It will develop a micro burr rather fast.

 

[Kawa]

I don't really know. They sold lots of stones and changed them. My Suehiro 1000 is definitely different, although both soaking stones.

Did you, or anyone else reading this, ever tried a superstone 1000?

It's the only 1000 I have (Have a chosera 600 as previous step and a shapton pro2000 and superstone 2000 as next step. Not saying I'm using all 3 as progression per knife).
People say 'master the 1000', but I think my ss1000 is my stone I ruin most edges on. Lately I skip it and go chosera 600 -> pro2000.
I find the 1000 very soft, I like the feeling during sharpening, but most of my edges are better if I skip this stone...
it gives a very hazy/matte finish. I can imagine its a nice stone for contrast making. But how is if for sharpening? I want to hear from other users, I dont want to give up on getting better with this stone, if it's a regulair usable stone for edge improving.

 

[kayman67]

All Super Stones are rather soft. With proper consistency/pressure, they work for you. Otherwise, no.