Stones for my shibata kotetsu gyuto

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mags88
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Stones for my shibata kotetsu gyuto

Post by mags88 »

Hi there,

looking to purchase some stones to go with this knife. I've been reading all over the place about what stones I should use.

One piece of advice was to use a 2000 & 6000 stone - would this be an optimal route with some stropping?

However I will have some other knives used at work which get abused by staff so considering ;

1000 / 4000 & 6000 to maintain them. Or 1000 / 2000 & 6000. However I am curious wether i need the in-between stones and just get 1000 or 2000 & a 4000 or 6000.

I realise there is no right answer here as each combination will do the job. Just looking to see what you al think.

Cheers.
bruin
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Re: Stones for my shibata kotetsu gyuto

Post by bruin »

Depending on how much abuse you’re talking about, you may want a lower grit stone. Most would recommend starting a dull knife on around 500 grit and you’ll want even lower for chipped knives & other repair work. I have a 220 and 600 in my kit and they do come in useful, but especially the 220 I don’t break out too often.

As for the medium and higher grits, you can lose out on some edge consistency when you skip from too coarse to too fine, but as you said you’ll be fine with any of what was recommended to you. Your Kotetsu is going to come really sharp and hold the edge fairly well, so 2k/6k would indeed be OK for a while, but eventually you’ll want a 1k (and like I said, lower than that too).

Just for perspective (and I’m no super expert or master sharpener or anything), lately for my weekly sharpening I’ve been doing 1k/2k/5k and getting results I’m happy with. But as you said there’s no “right” answer and the most important thing is to do experiment yourself and see what works for you.
nakiriknaifuwaifu
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Re: Stones for my shibata kotetsu gyuto

Post by nakiriknaifuwaifu »

If you're on top of sharpening your knives you won't need to touch the 500 stone often with your shibata, so that'll be primarily for your coworkers knives.

I'd suggest a coarse diamond plate (Atoma, DMT, etc.), which you can use to flatten your stones and for your coworker's knives. The shapton pro 1000, shapton pro 1500, gesshin 2000, suehiro rika 5000, gesshin 6000, and Kitayama 8000 are all really nice stones, so it depends on your budget and how refined you want your edge.
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Re: Stones for my shibata kotetsu gyuto

Post by Robstreperous »

So let me tell you a secret... those grit ratings? They're close but they vary from manufacturer to manufacturer. One man's 4K is another man's 5K.... A rule I like to follow is if I"m working within a single manufacturer, same line, try to double it. I.e., In a pefect world go from 1K, 2K, 4K, etc... Of course rules are made to be broken.

The advice about not needing a 500 right away is sound. I have one but it's mostly for repairs or friends' knives since I stay on top of my own.



So since you asked specifically about the Kotetsu I think I'd like to see you tighten up on your progression. It's such a fine, thin, blade it really does benefit from the tighter jumps. I go 1500 / 3000 / 5000 on mine. (Nubatama). If you can swing it those 3 stones will serve you well.

If budget's tight and you can only swing 2 stones I think I'd still rather have you tighten up on you progression. I'd opt for going 2K to 5K instead of jumping to the 6.

But... as Bruin said, If you're dead set on taking it to 2k/6K on only 2 stones that'll be alright for a while. But the time will come and you're going to want to fill in the middle with something around 4K.

BTW... since you mentioned coworker's knives and such I'm a big fan of the mantra "Master the 1K". 80% of the time a 1K / 3K progession will suit most people just fine. Plus... the 1K well applied will set up any of the finer stones for success.
Peter Nowlan
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Re: Stones for my shibata kotetsu gyuto

Post by Peter Nowlan »

500, 1,000, 6,000 will create a beautiful edge on that knife. Don’t be afraid of a coarse stone, you just need to use pressure wisely. I start every knife on a coarse stone and often use two in a progression depending on the level of dullness.
If I’m not staring coarse then I’m honing the blade in which cAse I’ll start at 2K and it’s very quick.

Nobody here is wrong, just telling you how I would tackle the knife.
Robstreperous
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Re: Stones for my shibata kotetsu gyuto

Post by Robstreperous »

Listen to Peter. If he says 1K / 6K is fine then it will be fine.

I’m still going to stay tighter but if in doubt... see above.
mags88
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Re: Stones for my shibata kotetsu gyuto

Post by mags88 »

Thank you very much everyone for your input! I am still debating my options.

My location limits me on stones, my availability is imanishi stones. A setup being considering and advised by the seller is a 220 Aratokun stone, 800 dragon stone, 2000 bester & finish on the Arashiyama 6000 stone.

I just need to decide on a budget. I shall let you know what route i go ... !
Peter Nowlan
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Re: Stones for my shibata kotetsu gyuto

Post by Peter Nowlan »

I should clarify myself when I say 500/1k/6k.
This is based on my experience with these knives and pretty much and knife of this caliber. This progression is successful assuming that all the work is done on each stone, squeezing the goodness out of every stone used
(I don’t suggest that we should rely on the 6k to make the knife sharp as that should happen at 500 grit. )

I don’t think there is any bad progression, the one I mention is popular because it’s what lots of folks can follow based on their collection of stones, coarse medium and fine.
I’ve done these particular knives at 400, 1,000 and 8,000 and was absolutely startled by the edge. It’s such a nice knife that it will make any sharpener feel like a rock star. Every time I work on one I feel like the best knife sharpener in Canada, then 15 minutes later that feeling goes away but it’s cool while it happens.

As I said there are no wrong answers and no “must follow” progressions. The only must do’s are the fundamentals.
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lsboogy
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Re: Stones for my shibata kotetsu gyuto

Post by lsboogy »

Robstreperous wrote: Wed Sep 02, 2020 7:51 am So let me tell you a secret... those grit ratings? They're close but they vary from manufacturer to manufacturer. One man's 4K is another man's 5K.... A rule I like to follow is if I"m working within a single manufacturer, same line, to double it. I.e., In a pefect world go from 1K, 2K, 4K, etc... Of course rules are made to be broken.


BTW... since you mentioned coworker's knives and such I'm a big fan of the mantra "Master the 1K". 80% of the time a 1K / 3K progession will suit most people just fine. Plus... the 1K well applied will set up any of the finer stones for success.
Great point about different manufacturers having different grits assigned to a number. Nominally, a 6K stone should have grit about 2.5 microns (or 1 micro inch) in diameter as the basic grit size. I have the luxury of a SEM to play with occasionally at work, and I did some looking at a few stones on steel for scratch size and depth - what I found was pretty eye opening to say the least.

The first thing to remember is that a 6K stone has an AVERAGE grit size of 2.5 micron. My Kitayama 8K (nominal grit size is about 1.8 microns) showed scratches between 1.3 and 3 microns, majority being centered around 1.9. A Nubatama platinum 6K stone showed scratches between 2.1 and 2.6 microns, with the majority right around 2.3. Looking at other stones, natural stones tend to have fairly uniform grit size compared to most man made ones - at least the ones I own - mostly Belgian Bleu and Japanese Kyoto stuff. And high end man made stones also seem to trend to more uniform grit - the Nubatama stuff I have been using lately is about as uniform as I have found in any stone. This can be important in finishing, as like my Kitayama stone, an 8K stone with high percentage of bigger particles (Kitayama has small percentage) will not put as good an edge as one with more uniform grit size.

The reason for this is how they manufacture ceramic powders - I deal with this in MLCC (Multi Layer Ceramic Capacitors) at work - they used to use very fine powders to get great dielectric and capacitance in a given size (think about cell phones and how small the parts are), but a couple of years ago we started seeing some variance in capacitance and dielectric behavior (I design stuff that your lived depend on if you fly, so we get far into the basement details of parts) - turns out that many of the big suppliers were using 1 micron powder instead of the previous 100nm stuff - far cheaper and fires in shorter time so they can get more product out faster. They use very fine mesh screens to isolate specific size powders, and the screen can be made with high or low precision. So just as we started seeing loss of precision in powder size in our parts, I have noticed the same aspect in whetstone manufacture - cheap ones seem to have large variance in grain size, where more costly stones seem to have less. My big red brick is pretty good (6.5-10 micron, with most centered right at 8) but the Nubatama 1200 is 6.7-8, with the majority right at 7.6).

Just some food for thought, but if you are looking into finer aspects of sharpening, take care where you get your stones, and look into how they are made. Shapton stones also seem to have very uniform grit size, as do some others. But remember that the grit is an average, and IMHO I would guess one of the bigger variants in how a stone puts an edge on a blade. And as some chinese firms are now selling whetsones, I would expect to see a larger variance in grit size with even cheaper stones. A 1K is not always a 1K.
mags88
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Re: Stones for my shibata kotetsu gyuto

Post by mags88 »

mags88 wrote: Thu Sep 03, 2020 12:39 am Thank you very much everyone for your input! I am still debating my options.

My location limits me on stones, my availability is imanishi stones. A setup being considering and advised by the seller is a 220 Aratokun stone, 800 dragon stone, 2000 bester & finish on the Arashiyama 6000 stone.

I just need to decide on a budget. I shall let you know what route i go ... !
Anyone got any thoughts on this stone setup? Experience with these stones?
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