Flattening a Hard Silicon Carbide Honing Stone

[Trafalgar]

So these guys that are worried about absolute stone flatness (essexalan's post) aren't delivering a very sharp knife to their customers? That doesn't make sense to me, it may be so though, the most expensive knife for the shop that I've ever bought was a Case pocket knife for about $30. I have a few kitchen knives that cost more but not drastically so. I don't have a doubt that somebody could get the Case sharper, but I manage to get it sharp enough. Of course, a $30 pocket knife didn't have an edge that was all that great, but it wasn't that bad either.

 

[swagman]

Charles; my thoughts are with those that have withdrawn their membership over recent years due to the unsavoury attitude of a very small group of individuals.

regards Stewie;

 

[Jacob]

.....
my fascination with sharpening everything by hand carries over to knives and straight razors (and scissors, and pencil sharpeners, and...whatever else you can get on a stone). ....

I don't do razors but I do do scythes and sickles, other stuff besides woodwork tools. When I first reverted to freehand sharpening (convex bevels and all!) I was so pleased with myself I sharpened everything I could lay my hands on - rusty old tools in the scrap heap even. Didn't take long.
My fascination is with how much you can do with with how little, often by hand without props, training wheels etc. Probably comes from reading all those "Boys Own" real and fictional accounts of survival and adventure!
Also I do admire the hand made traditions in many things - rarely perfect but often full of life and quality. Not that there's any virtue in being less than perfect but there is something attractive about optimisation - the leaving off at the point where no further working would add value, e.g. the slight irregularity of dovetails done freehand but very quickly.

 

[essexalan]

Most knife sharpeners sharpen longer knives like Gyutos in sections across the width of the stone using light finger pressure over the bevel, hence they demand a flat stone a concave stone would only correspond to certain areas of the natural curve of the knife. You certainly end up with a concave area in the middle of the stone after/during sharpening.
I think that Japanese knives like their chisels traditionally arrived in an unfinished state so you had to change the handle and hone the edge to your requirements. Hence I have never had such a knife sharp out of the box, something the public seem unable to understand. I always sharpen on stones and never steel.

Even my Yorkshire spud peeler got the sharpening treatment and much betterer it were ;0) Scissors I can get sharper but not sharp so WIP. I do have a hairdressing friend who spends over £250 plus £50/year sharpening on her scissors, I did not offer to sharpen her scissors!

 

[D_W]

So these guys that are worried about absolute stone flatness (essexalan's post) aren't delivering a very sharp knife to their customers? That doesn't make sense to me, it may be so though, the most expensive knife for the shop that I've ever bought was a Case pocket knife for about $30. I have a few kitchen knives that cost more but not drastically so. I don't have a doubt that somebody could get the Case sharper, but I manage to get it sharp enough. Of course, a $30 pocket knife didn't have an edge that was all that great, but it wasn't that bad either.

Sometimes I don't know how you draw some of your conclusions.

The ones who are using absolutely flat stones, first, don't appear to be serving any customers and second, they're not delivering sharp beyond what they would deliver with a stone that was new spec.

The very high end of knives includes hand made and hand finished stuff by makers like Shigefusa, they are ten times what i'd ever spend on a knife - they are very carefully finished. There are a tiny few sharpeners "professionally" sharpening those knives for people for about the cost of what you or I would pay for a new knife, which could only make the average person shake their head. I doubt their customers are chefs.

The rest of the professional sharpening that occurs is done on a machine or five for about a dollar a knife (that's the going rate here). The professional chefs I've observed using western knives do their sharpening with something similar to a norton india stone and finishing by just ripping the burr right off and then steeling as necessary.

The folks fascinated with flattening stones are hobbyists who are not using those stones to turn around knives for pay. I can't imagine pulling out a new norton india or SiC stone and flattening it to sharpen a knife.

 

[D_W]

Most knife sharpeners sharpen longer knives like Gyutos in sections across the width of the stone using light finger pressure over the bevel, hence they demand a flat stone a concave stone would only correspond to certain areas of the natural curve of the knife. You certainly end up with a concave area in the middle of the stone after/during sharpening.
I think that Japanese knives like their chisels traditionally arrived in an unfinished state so you had to change the handle and hone the edge to your requirements. Hence I have never had such a knife sharp out of the box, something the public seem unable to understand. I always sharpen on stones and never steel.

Even my Yorkshire spud peeler got the sharpening treatment and much betterer it were ;0) Scissors I can get sharper but not sharp so WIP. I do have a hairdressing friend who spends over £250 plus £50/year sharpening on her scissors, I did not offer to sharpen her scissors!

Some of my wife's friends drop of knives for me to sharpen. I always sharpen them on an IM313 setup that ends with a mid grade arkansas so that it doesn't take 10 minutes a knife to sharpen something they'll use as a scraper the next day, anyway.

The japanese knife craze is something that exists more on the internet than in person. For the rest of the knives that are made to about saw temper, a smooth steel is a far better idea than sharpening every time they're dull. But if you're using a japanese knife and you don't steel, that's probably good, as steels break the edge instead of straightening them like they do on the various western knives.

Knives designed to be steeled are better maintained by steeling between sharpening, more economical in time and knife life.

 

[swagman]

David; you mentioned you use the Norton IM313 System. Did you bother purchasing the premium Straight Edge. https://www.sharpeningsupplies.com/Chec ... 0C203.aspx

regards Stewie;

 

[essexalan]

The only hand forged and finished knives I have seen have a somewhat rustic appearance none of which matters it is all about the heat treatment, grind and the ability of the steel to take and hold a sharp edge. As you say way beyond what I would pay for a knife but none the less fine pieces of work. Plenty of pro sharpeners on knife forums if you take a look but as you say not a lot considering how many are sold.
I flatten my stones for knife sharpening for the same reason I do for other tools, it works for me! Already had the discussion re steeling elsewhere, suffice to say I like fresh steel on all my sharpened tools. I suppose you could say that cooking as well as woodworking is just a hobby to me and I like sharp tools for both and they get sharpened only when I consider they need it.

 

[D_W]

David; you mentioned you use the Norton IM313 System. Did you bother purchasing the premium Straight Edge. https://www.sharpeningsupplies.com/Chec ... 0C203.aspx

regards Stewie;

No. I already have straight edges better than that one, but it's not a place where I'd use them (I use them only for toolmaking). I don't know how dead flat my stones came, two of them are norton synthetics and the third is a stone that Dan's sells for about $50 (only because it's large).

I have prepared cap irons on those stones without ever checking the stones, and the cap irons have fit well on a flattened iron. That's pretty much my gold standard. I use the whole stone of each type as much as possible and presume that they will never need to be flattened functionally, but the crystolon stone will eventually go partially out of flat, I'm sure (I don't use it to prepare backs of anything - it's a superb bevel and knife grinding stone).

I consider a new IM 313 more or less a luxury item. They're expensive, but the long stones make sharpening and grinding long curved blade knives (like chef's knives) very quick. I've heard of a few people chancing on older versions at yard sales, and sometimes they are for sale inexpensively on ebay. Nice rig, but difficult to flatten the stones on them.

The only knives that I have that are totally flat are chip carvers and a couple of pocket knives with wharncliffe blades and sheepsfoot blades.

 

[Trafalgar]

Charles; my thoughts are with those that have withdrawn their membership over recent years due to the unsavoury attitude of a very small group of individuals.

regards Stewie;[/quote

I'm sure they appreciate your sentiments.

 

[D_W]

The only hand forged and finished knives I have seen have a somewhat rustic appearance none of which matters it is all about the heat treatment, grind and the ability of the steel to take and hold a sharp edge. As you say way beyond what I would pay for a knife but none the less fine pieces of work. Plenty of pro sharpeners on knife forums if you take a look but as you say not a lot considering how many are sold.
I flatten my stones for knife sharpening for the same reason I do for other tools, it works for me! Already had the discussion re steeling elsewhere, suffice to say I like fresh steel on all my sharpened tools. I suppose you could say that cooking as well as woodworking is just a hobby to me and I like sharp tools for both and they get sharpened only when I consider they need it.

Certainly doesn't hurt anything if you flatten your stones.

FWIW, I did once steel a stainless japanese knife knowing that it was overhard for steeling, but just wanted to see what would happen. It just one of those western style chef's knives that cost about $70, bottom of the barrel for large japanese knives, but it's really a very nice knife (hardness claimed to be 61, probably accurate). It didn't chip out big chunks or anything, but you could tell by the sharpness that it had chipped a tiny bit of the edge off all the way along and was far less sharp after a light steeling than it was to start with. German knives, other way around, steeling works wonders with them, and I'd do it before sharpening, too, because you'll have a lot less that you have to grind off.

If I steel a henckels knife 20 times over several months and then have to sharpen it (wife's knife), the inexpensive japanese knife (relatively, still expensive) is still as sharp as the henckels knife at the same sharpening interval with no screwing around in between. Put both of them in kitchen prep in a restaurant, and the same probably wouldn't be true.

 

[essexalan]

Probably talking about Tojiro knives which are a bargain in VG10 even in the UK definitely recommend them. A smooth steel does seem to burnish these knives but I would not call it sharpening. Anything over about approx RC 60 will chip before it deforms. My sister has had about every knife used by TV chefs ever made and they always ended up blunt steel or no steel, so I always took my diamond plates along when visiting to sharpen them. Some were crap steel anyway but most I used to get pretty sharp. She eventually bought a set of Global knives and you can imagine the state they ended up in.
Line work in a kitchen is something else and the inability of Japanese knives to handle bone without chipping would be a problem, add on the fact that knives are constantly "borrowed" and I would not take a Shig into that environment.
My R-2 knife lasts a lot longer than VG10 and the HAP40 longer still to the point where I give it a sharpen because I have the stones out.

Anyway flat stones rule! ;0)

 

[D_W]

Yes, tojiro. I do have a blue steel tanaka santoku that I actually sharpen correctly, but it is banned from the kitchen. Even the tojiro will chip of slightly and lose its keeness with a light touch on a smooth steel (another thing that's not easy to find these days - the smooth steel). those are as "high end" as I would go, personally, because they last for months between sharpenings and can be sharpened in a couple of minutes. The payoff for other things isn't there in terms of durability vs. sharpening, and the crystolon stone is much nicer to use than a diamond hone. Less portable and more messy, but we are woodworkers and that stuff can stay in the shop.

I worked in kitchens in mid-grade restaurants as a kid and college student (like $20 a plate here now), and in most of those places, I saw knives that I'd describe as food service cheapest. When they were dull, they were sent out. Very soft.

Most of the knives my wife brings (from her friends) are soft mid carbon stainless, and they just melt away on a medium carborundum stone, and don't take that great of an edge on an ark stone (ark stones will cut saw tempered steel or softer aggressively). But I have gotten a look at some less expensive knives that are good quality, like the spanish origin henckels knives. I like them just as much as the german ones, they feel the same on the stone and they're less expensive. The current german knives are underwhelming, but soft knives love a steel and you can correct a whole lot with a steel. I guess that's the point.

 

[essexalan]

Tools are for using and that knife is screaming "Use me"! Just don't let HID use it or you will have a wreck. Carborundum does tend to rip steel away and not ideal for sharpening soft steel. The diamond plates I use are well worn and quite benign compared with a new diamond plate.

Victorinox are mostly what I use for heavy work but they are old and I have no idea how they compare with the modern knives.

 

[D_W]

Tools are for using and that knife is screaming "Use me"! Just don't let HID use it or you will have a wreck. Carborundum does tend to rip steel away and not ideal for sharpening soft steel. The diamond plates I use are well worn and quite benign compared with a new diamond plate.

Victorinox are mostly what I use for heavy work but they are old and I have no idea how they compare with the modern knives.

They are probably harder (than the new ones). The henckels knife I have is probably 440C, but the other knife that I have (wusthof) is 0.5% carbon steel. It is soft, but takes a lot of abuse. Given the state that my wife's friends knives show up in, I don't think most people would notice a difference.

(I keep the blue steel santoku stored out of sight and above my wife's height and use it from time to time. It's not an expensive knife, another one in the range of $70 -easy to maintain as long as it's dried after use, but it is sharpened with no secondary bevel and it generates complaints from everyone who uses it, I guess because people are used to dull knives. It is pure pleasure in fruit and vegetable work, and good for boneless meat work)