Effects of renge and su

[Nick112]

hi
Read that some says more renge in a suita (f.e Ohira) make it cut faster? What are your opinions? Since I see some suitas has renge all over the stone while some only have renge in parts of the stone.


Also the holes, do they have any effect on sharpening properties? Seen a few stones are without holes, and some stones have layer deeper down with holes

 

[childermass]

Renge is difficult. Depending on where you look you read that it increases or decreases cutting ability or doesn’t do anything at all.
In my limited experience it does not really make a difference as I got stones with and without Renge that have comparable cutting abilities so I think it’s just a cosmetic thing.
What really matters is how much abrasive particles are dispersed in the matrix of the stone and how fast they are released during use.

 

[jaknil]

The range itself has not really any effect on the sharpening ability. But a stone which has range in one end, and not the other, is more likely to not beeing uniform in hardness and sharpening ability.
So I look for range all over the stone if I can get it.

Su does not effect the sharpening, for most stones. In rare cases they can give you a hard time achieving the best result.
Most suitas though, does not have su.

Look out for the hardness of the stone. If a newbee look for LV2,5 - 3,5 (JNS scale).

 

[XooMG]

I like having holes in my fingerstones because they give me a little window to see my progress while I polish.

 

[Benuser]

I like having holes in my fingerstones because they give me a little window to see my progress while I polish.

And for sure it allows easy bleeding which highly contributes to patina formation.

 

[Nick112]

Jaknil, how do su makes it harder to avhieve the results?
Do you feel the holes when sharpening? In what way can they hinder? Does it take longer time to finish the sharpening?
Thanks

 

[Xenif]

I like having holes in my fingerstones because they give me a little window to see my progress while I polish.

Self circulating slurry control, brilliant.

OP, having su pockets kind of like having a pot hole on your stone. If they are small and shallow then they just kind of fill with slurry not a huge issue for sharpening, but pita if you are using it to do polishing.

 

[Nick112]

Thanks everyone taking the time to answer. As a noob venturing into buying my first stone, why and how is it a pita for polishing?

 

[childermass]

Because sometimes not broken down grit is trapped in su and released during polishing giving deeper scratches making the process more cumbersome.

 

[jaknil]

Nick: I have about 10 suitas. I have tried aprox 50+ more.
I have never had any problem with su.
I have only on one stone experienced a problem. The su had a hard edge, and I had to kind of "sharpen around" as in not put to much pressure one the edge at this point.
I dont think of su as a problem, but if you are unlucky, it can be.

 

[Nick112]

Hi jaknil, thanks for taking your time to answer. And thanks for sharing your experiences.
In your opinion, should I try to avoid ohira suitas that are like renge on one end and like yellow color on the other half?
For sharpening ao sg as and want to get a really nice edge, is ohira suita one of the best choices?
You dont have any suitas that you would be willing to part with?
In your opinion do renge have any impact on the sharpening properties? Like cuts faster or more coarse etc?

 

[Slipstenar]

Well...

What about the renge, i have many stones with renge and in my opinion its just the looks that get satisfaction about it.

But su, this can be a mess if you are unlucky. I have had some stones where the su got some hard particles in them, in fact i have one in my bottom drawer that got this problem. And then I have some stones with su that doesnt make anything its just holes in the stone..

 

[metamorpheus]

It depends. I know that's not the answer you want to hear, but it's the truth. I don't think they cut fast because of renge. I think it may be that the ohira aka(pink) renge suita with really prolific patterning is more likely to be from a shallower tenjyou layer with a grit more comparable to 4-6k vs 6-8k from some other suitas. Because its coarser/softer, it seems faster but you're not really comparing the same thing. It's also possible to have a harder aka renge from the tenjyou layer that's really fine.

Bottom line is you need an experienced seller that you can trust who will answer your questions to help you find exactly what you're looking for. I got my first suita from Badgertooth and my second from Nutmeg. Both are of excellent quality.

The one thing you can say with certainty about ohira aka renge is that pink slurry looks really cool...

 

[jaknil]

Hi again
The best thing is ofcourse to try a stone before buying it.
If this is not possible, then buy from a trusted seller. Eg one of the regulars on BST or one of the good knife shops.
I get 90% of my stones from JNS.
I happen to live quite close, so most often I´ll try tem out before buying

Only if you can not try it out or buy from a trusted seller, then you should worry about the looks.
In that case I´d not get one with yellow colour in one end. Often the yellow coloured part is harder.
Some think it´s ok, as they get different sharpening properties in one stone. However I like my stones to be uniform.

And if you want to start out with a super natural, then a Ohira Suita is a good choice.
Im not sure it´s the renge that makes the ohira suitas as nice and fast, but it just happens to be a fact that a lot of Ohira suitas with renge cuts very fast.



I was about to write that I dont think I have a stone for you, but I just remembered one Ohira suita, that I keep at work (I´m not a chef).
Its nice with a lot of beautifull renge. It is stone no 4 in this thread:
https://www.kitchenknifeforums.com/threads/vintage-kyoto-natural-stones.35914/#post-534870
As it´s not so thick, it should be mounted on a piece of wood, also to stabilise it.
I´ll take a couple of photos when I am a work.
This stone is an affordable way of trying the Ohira magic.

Actually I do have a few other stones I´d sell, but this one is the one that comes closest to your wishes.
Maybee I could mount it on wood before a sale.
As I write this I´m allready having a bit of "sellers remorse", so I´ll just consider it one last time, when I take a few photos for you tomorrow.

 

[jaknil]

Dry and wet