What kind of sharpening stone do I have?

[Starkman]

Hello all,

I just bought a Forschner Victorinox and a two-grit stone (the stone was only $10.00 at a restaurant supply store).

It's a big ol' stone, made in China, and says on it "Combination Sharpening Stone" and "Aluminum Oxide." Other than the dimensions given (about a foot long!), the rest of the writing is in Chinese.

Nothing is given about the grit, which is really weird--it's pretty rough on one side and pretty smooth (though not super-polished smooth) on the other side. Finally, I don't know if it's a water stone or an oil stone. ("Then why the hek did you buy it, idiot?" you ask? Oh, I don't know. Because it was cheap?!)

So, anyone got any ideas? Will it work for my Forschner?

Thanks,

Starkman

Edited January 25, 2010 by Starkman (log)

[Octaveman]

Most of the time stones like these are 800/2000 or something close to this. It's most likely a water stone. picture?

[Starkman]

Most of the time stones like these are 800/2000 or something close to this. It's most likely a water stone. picture?

Okay. So, if I use oil, would that be a problem?

(Yes, I've used oil on it already. I called up a local knife/tool sharpener fellow, and he said oil's the way he'd go.)

Oh, and no photo. Sorry. I have no camera.

Thanks,

Starkman

[David A. Goldfarb]

It's my impression that most stones can function as oil or water stones, but once you decide it's an oil stone, there's no changing your mind about it.

[Shalmanese]

I don't know if this is the correct way of doing it or not but I use cheap stones to start and expensive stones to finish my knives. I sharpen on the rough side until I can feel a burr, maybe 30 strokes, then another 10 or so on the smoother side before finally finishing on a Japanese 4000 grit stone.

If you don't finish on a fine stone, your edge will be horrible

[scubadoo97]

I'm not sure that's exactly true. As an experiment I've been using just one stone, a 1000 grit Shapton glass stone to sharpen and touch up my most used Japanese knives. They are very sharp and function quite well at this level of finish. I should also mention that I do a few passes on a chromium oxide loaded leather strop after the 1000 grit stone. Doesn't take more than 4-6 passes on each side.

[David A. Goldfarb]

Most butchers that I've seen in the U.S. aren't using Japanese waterstones or particularly fine stones as far as I can tell--usually the common two or three sided Norton oilstones and steels--and they manage to do their jobs well enough, so I wouldn't say that they produce a "horrible" edge. I used similar approach for many years before switching to Japanese waterstones, and I could get a sharp functional edge that way, and most people who picked up one of my knives would say it was sharp. Now I only take out the oilstone when I'm reshaping an older knife.

Waterstones with good technique can produce a much sharper and more refined edge and will open up new culinary possibilities and make knife work more of a pleasure, but basic technique with an ordinary oilstone is probably good enough for most kitchen tasks.

[paulraphael]

I don't know if this is the correct way of doing it or not but I use cheap stones to start and expensive stones to finish my knives.

That's a perfectly reasonable way to go. The cheap stones in the beginning aren't going to hurt your edge in any way. What you get from nicer stones (and some cheap stones are actually pretty nice) is qualities like better feedback, quicker results, less dishing ... stuff that makes your life better, not your edges.

If you don't finish on a fine stone, your edge will be horrible

It will be coarser and toothier, but if it's been well sharpened on the medium stone it won't be horrible. It will do some things especially well, like slicing slimy or fibrous foods. You can shave with a knife that's been well sharpened at 1K.

But it won't push cut as well as a polished edge. And it won't leave the kind of glass-smooth, undamaged finish on food that a polished edge will leave. You give up some big advantages, like cut herbs that stay fresh, and fruits that don't brown.

[Shalmanese]

I use carrots as a test of sharpening and when I take it as far as I can go on a cheap stone, it requires noticeable pressure to get through a carrot, often more than before I started. Just two swipes on a finer stone and the pressure is noticeably reduced. 8 more and it's as sharp as it'll ever be.

[paulraphael]

I use carrots as a test of sharpening and when I take it as far as I can go on a cheap stone, it requires noticeable pressure to get through a carrot, often more than before I started. Just two swipes on a finer stone and the pressure is noticeably reduced. 8 more and it's as sharp as it'll ever be.

If two swipes (or even 8) on the fine stone is making that big a difference, then I suspect what you're actually accomplishing is burr removal. Coarse stones will raise a significant burr on the edge, and it can be surprisingly hard to remove. The burr can end up as minute, perfectly straight extension of the edge (called a wire edge) and is one of the more vexing problems in sharpening, especially with some knife steels. The cheapest knives and the most expensive knives often put up the biggest struggle. That wire edge jurts performance and durability.

Generally, going from a medium stone to a fine one requires a lot of polishing to fully remove the coarser scratches ... way more than a few swipes. So I'm suspecting that what you've been doing on your fine stone is really just removing the burr; you're going from a bad 1k edge to a good 1k edge. To really take it to a polished 8K (or whatever grit your stone is) edge will take a lot more time on the stone ... and will probably produce mostly subtle improvements.

[scubadoo97]

I deburr on a hard felt pad which is suppose to remove a wire edge but find a great improvement with a few passes on the leather strop. I suspect the strop is correcting some small flaws in my technique but could be removing a fine burr.

[paulraphael]

I use a felt pad too. I still find that I don't do a great job of getting rid of the last little bit of wire edge, even though most of my knives are much easier than average to sharpen. It took me a long time to figure out I was having this problem.

[Starkman]

Okay, so speaking more of sharpening,

There's an old fellow down a few blocks who is a professional knife/tool sharpener. He used to have accounts with many of the large grocery store outlets (Safeway, etc), namely to sharpen butcher knives.

He seems a bit unorthodox (by standards I've read on this site) when it comes to sharpening (if I understood everything he was telling me). He says he's hardly too concerned about the sharpening angle of most common knives--says it's a lot of BS about having to be so precise. Further, he's totally against using two hands when sharpening; the pressure of the fingers of the "other" hand on the blade as a guide will only create unevenness.

He does sharpen all knives on a machine and, according to others around town, whom I asked, he does a very good job. For $4.00 to do my Forschner Victorinox, I might just let him have the go at it, since my stone--see the very first post in this thread--will probably not come near as close to achieving what he will be able to do.

But I wonder, in view of his lack of concern for angles, and without discussing this issue with him, will my knife get the best angle for the steel if I let him sharpen it?

I'll need to find out from folks here and perhaps from Forschner what can be expected from this knife from either either types of angles.

Starkman

[Starkman]

Felt pad???

Picture anyone?

[paulraphael]

You'd never want to give a good knife to someone like that. The world is full of professional sharpeners who are in the business of cranking out serviceable edges in a hurry, using power wheels or belt sanders. They will destroy a good knife in the blink of an eye and take years off of the life of any knife.

I made the mistake once of following the sage old advice, "just ask where your butcher gets them sharpened." Luckily all I had was Chicago Cutlery knives at the time. They came back with stupefying amounts of metal ground off the edges. Three more sharpenings like that and there'd be nothing left! Oh, they were fairly sharp, at least for the ten minutes that that kind of knife holds an edge ...

Services like that make sense for guys like my butcher, who actually rents his knives from the knife grinder. Once a week a guy comes by, takes all the old ones and replaces with a freshly sharpened set. The lifespan of these knives is probably a couple of months, but they're all $10 knives, and the clients pay a flat rate (they have to ... the grinding service is run by the mob).

This is a good arrangement for butchers, because raw meat is easy to cut; ragged edges are pretty unobtrusive after cooking, and the knives are mostly used for trimming anyhow; big jobs like cutting steaks from a loin or rib section get done on the bandsaw. His knives are never really sharp, but they're always serviceable. The same arrangement would never work for a prep cook who's trying to do precise work.

[scubadoo97]

Felt pad???

Picture anyone?

A felt pad and block can be seen and purchased here

http://www.japaneseknifesharpeningstore.com/SearchResults.asp?Cat=27

[Edward J]

You can "convert" a stone from oil use back to water use, the same way you can "rescue' a dished-out, plugged up flea market stone:

Put the stone in an old pot and fill with cold water, bring slowly to a boil. Turn off heat and let cool, rinse the stone off, repeat as neccesary.----In other words, the same method you'd use to blanch off bones for stock....

The only reason I'm not a big fan of using oil stones is that becasue in just about every kitchen I've worked in, I see otherwise good stones plugged up and glazed with crud and vegtable oil. Vegetable oil is a big no-no, as it will get gummy and harden up fairly quickly. Most of the oils used for sharpening are toxic or have some kind of a kerosene base--not the kind of thinkg you'd want in your tookbox or kitchen.

But like the others say, cheap stones are good for re-profiling, re-tipping, etc.

For honing a lot of woodworkers use green honing paste (about a 8000 grit equivilent) rubbed on leather strops, hard felt blocks or even MDF wood boards. The honing paste is fairly cheap and lasts for a long time.r

[paulraphael]

I wrecked my leather strop, and since I felt I didn't deserve another one, started using paper. I just found some 100% cotton paper that didn't seem to have any abrasive coatings on it, and glued it to the same block my leather strop had been on. I rub green chrome oxide powder into this (same thing that's in that paste). Works fine. Stropping takes a couple of minutes, and lets me put off the water stones for a few weeks.

Some purists dislike strops, and do all their touch-ups on fine stones. I've been won over by the speed and lack of mess.

[Starkman]

You'd never want to give a good knife to someone like that. The world is full of professional sharpeners who are in the business of cranking out serviceable edges in a hurry, using power wheels or belt sanders. They will destroy a good knife in the blink of an eye and take years off of the life of any knife.

Thanks very much for that input!

You can "convert" a stone from oil use back to water use, the same way you can "rescue' a dished-out, plugged up flea market stone:

I like that idea. Thanks.

The only reason I'm not a big fan of using oil stones is that becasue in just about every kitchen I've worked in, I see otherwise good stones plugged up and glazed with crud and vegtable oil. Vegetable oil is a big no-no, as it will get gummy and harden up fairly quickly. Most of the oils used for sharpening are toxic or have some kind of a kerosene base--not the kind of thinkg you'd want in your tookbox or kitchen.

I'm using what's called Butcher Block (pure mineral oil as far as I can tell). That should be fine, I would think, wouldn't it?

A felt pad and block can be seen and purchased here

http://www.japaneseknifesharpeningstore.com/SearchResults.asp?Cat=27

Thanks, scubadoo97!

Thanks,

Starkman

[cbread]

There are lots of appropriate ways to sharpen a blade. Belt grinders are not necessarily bad. A water cooled very fine grit belt on a slack belt grinder - used with care and discretion - works just fine as does a traditional whetstone. Clumsy use of powered sharpening takes off too much material and needlessly uses up the life of a knife.

One very good way to strop is to use a buffing wheel with a fine compound. Buffing wheels have to be used very carefully since they can grab and throw a blade with astonishing force. The grabbing happens so fast that there is no chance to respond. Some custom knife makers use a NYC telephone book under their belt as protection from flying blades. Regardless, the best edges I have ever produced wire from a buffing wheel.

[paulraphael]

Belt grinders have their place ... major reprofiling, repairs, etc...

Someone skilled can use them to sharpen a knife up to medium grit or so (Dave Martell at Japaneseknifesharpening.com uses them for all European knives and for Global knives). I think he takes them to around 2K.

I don't know anyone who does finishing sharpening on them on good knives. Waterstones are the overwhelming weapon of choice for most people. Equivalent results are possible by mounting fine grit automotive sandpaper on glass, but the sandpaper is so short-lived that this becomes tedious (I'm one of many who tried it and eventually bit the bullet and got stones).

Systems like the edge pro work on double bevel knives. They are slower, and don't offer much choice in stones, but they work. Oil stones work too, but they're slow and aren't available in the finest polishing grits.

Some people use kanabans (not sure if I'm spelling it right) ... iron blocks sprinkled with powdered abrassives. Sounds messy, but no reason it wouldn't work fine.

Buffing wheels can give decent edges, but round the edge slightly, because of the flexibility of the material. This has been studied a bit. You can always get a sharper edge on a stone or similar hard-planed surface.

[Dakki]

Every machinist I know (and a lot of people who aren't machinists) thinks they can sharpen on a bench grinder, and every one of them makes a mess of it. It's just too easy to take off far too much metal.

I just wouldn't give my good knives to someone who uses power tools to sharpen, period.