Knife Sharpening

December 18, 2004 10:25 AM

Why won't my knife sharpener sharpen? [+]

I have three different sharpeners, so I wonder if it's my technique (though each one requires a different method).
1. Is a 'steel', a solid, heavy, ridged metal rod. Requires nerve and speed and I never was able to get it right.
2. A hand held, almost horseshoe shaped plastic handle with two crossed over, 2-3'' long ridged rods sticking out. The knife is dragged hard across the point where the rods cross over. Doesn't seem to work that well.
3. Another handheld device, consisting of two interlocking sets of hard metal disks which are rotatable, again which is designed for the knife to be dragged hard across the intersection of the disks. Again, somewhat ineffective.

My favourite chefs knife, about 10'' long and wide near the handle, I bought when I did an undergrad course in catering. It should be quality as it was supplied by a specialist. I'm guessing I need to improve the way I use them. How?

posted by dash_slot- to home & garden (18 answers total)

A 'steel' does not sharpen knives, it hones them. If the knife was not sharp before application of the steel, it will remain so. Take a few swipes across this, alternating sides of the blade, before every use.

I don't know anything about the second device, and can't speak to it. The third device is a typical household sharpener. Mostly, these ruin the edge of a knife, but if you have a crappy blade and you just want to get some semblance of cutting ability out of it, these can be effective:

One set of disks is rougher than the other. Drag the knife towards you, applying little to no pressure, through the rough set three or four times. No more. Switch to the finer set of disks, and do the same thing five or six times. At the conclusion of this process you should have a knife that can cut.

Though if you have a nice knife -- supplied by a specialist you say! -- it should be sharpened by a professional on a grinding wheel, then steeled before each use.
posted by majick at 10:32 AM on December 18, 2004

Steels are useful only with already-sharp blades; they knock any dints and warbles. It's a blade re-alignment.

The plastic jobber has ceramic sticks. Once they're gummed up with metal, they're useless. You can try to scrubbie-pad the rods clean.

The metal discs are carbide. They should work, but I find that if they've any play, they're useless on anything but the sharpest knives (I suspect they act much like a steel, but slice off the dints instead of knocking them into line).

What will work is an evil little sharpener that has fixed carbide blades in place. It removes metal as it sharpens, which makes it appropriate only for dull blades, but damn does it do the job! It's called Accusharp and is made by Fortune Products Inc, of Marble Falls, TX.

Naturally, there are far better (but fiddly-er) sharpening systems (I suggest eyeballing the Lee Valley Tools catalog), but for sheer convenience and quickness, this sharpener is the best I've found.
posted by five fresh fish at 10:35 AM on December 18, 2004

Also, the use of a steel requires neither nerve nor speed. Yes, I know, you see experienced cooks thwacking away with the steel in a rather impressive and dangerous manner. It turns out that's all for show. You can get exactly the same result by using it slowly and carefully.

The Alton Brown method of using a steel is very good.
posted by majick at 10:42 AM on December 18, 2004

i guess this vaguely like a "steel", but anyway... what i use on our knives is a metal rod that looks a bit like a long round file (with plastic or bone handle) that once belonged to my grandmother. i hold the knife in my left hand, with forearm horizontal and resting against my body, knife horizontal and pointing away with blade to the left. then, with the right hand, i draw the "file" (the movement is more a "push" than a "draw") along the blade, so that the "file" is "sharpening" the blade at a fairly acute angle.

after a few swipes, i flip the knife over and so the same on the other side (now more like drawing than pushing). finally, on each side, i do the same (but only a single "swipe" each side) at a steeper angle to give a final edge.

it appears to work fine - we've had the same knives for several years and they still sharpen. the idea is the same as sharpening a chisel on a wetstone - you make a V with a fairly fine, but blunt point, then finish it off with a steeper final edge.

and after reading majick's link that sounds similar, except that in that case the steel is on a table. we also cut on wooden boards.
posted by andrew cooke at 11:08 AM on December 18, 2004

ps i hope this is obvious, but that is only for a flat blade. i have no idea how you sharpen serrated steel. our bread knife is serrated and so far it's just continued to work.
posted by andrew cooke at 11:11 AM on December 18, 2004

For home sharpening you really need some water stones that you use every six months or so. The steel is for the time in between. It is not hard to learn how to sharpen a knife well, and it is immensely gratifying. The key is that you need to raise a burr, a very small strip of metal on the edge that is folded over. You then do that on the other side, and then use the fine stone to take off the burr, leaving a sharp edge. Then you polish the edge and you are in business and the onions cry for you. No system that has interlocking wheels or rods will allow a burr to form, since the burr has to have somewhere (away from the stone) to curl.

This may all be too confusing as I have written it.
posted by OmieWise at 12:28 PM on December 18, 2004

Sharpening a knife with only a chunk of stone is a skill that takes practice to get right. If you want to learn that skill, by all means buy a cheaper knife for your practice. The skill is learning to get a consistent angle in the approach to the stone. Most sharpening systems for home consumers are built to make it easy to set the angle, but very few worry about the pressure which will take the nice gentle curve out of a chef's knife because you apply too much pressure in the center of the stroke. A question I have for all the "Chef's Mate" type systems is, if they work so well how come the butcher's department in my local supermarket has a grinding wheel instead?

My local supermarket sharpens knives for free. I let them--and I think I'm pretty good at sharpening.

For DIY, I've used one of these in the past and was very impressed with the edge it put on my knife. At the time I tried it out, I already had a stone and was happy with my skill. Looking at it, I'm wondering why I don't buy one now since my old stone needs to be dressed and I'm too lazy to do that. Hmmm.
posted by plinth at 12:33 PM on December 18, 2004

Is your knife stainless steel? If so, you'll need to have it sharpened by a pro at least once a year; more often if you use it heavily. I use my 8" chefs knife for most things, and although I hone it on a steel before each use, it has to go into the shop every six months like clockwork. My carving knife, paring knife, sandwich knife, and 10" chef don't get as much use--they get seen by a pro about once a year. My boning knife gets a lot of use but because of the nature of the work, doesn't get dull very quickly--about once every 18 months it needs a top-up.

Carbon steel knives keep their edge better than the stainless, but still need to be sharpened professionally from time to time.

Not sure where you are in the UK, but if you have a decent kitchen store anywhere near, if you phone them they ought to be able to tell you where to take your knives. Some stores provide this service (Divertimenti, in London, is one of them) but then you're without the knife for a week. I have a local guy who does mine for £1 per knife and they're back the next day.

on preview: You could, of course, be self-sufficient and learn how to use a water stone as OmieWise suggests...me, I'm too lazy for that.
posted by Tholian at 12:34 PM on December 18, 2004

Agrees with the above. First one is a hone (you could even use a leather belt for the same effect). If it is a high quality knife you could always invest in a lansky knife sharpening system, I have one and swear by it.
posted by squeak at 12:37 PM on December 18, 2004

Thanks folks. i will definitely investigate local expert sharpeners, and if they're not up to it, I'll find a way to do it myself.

All to the good. Cheers!
posted by dash_slot- at 1:44 PM on December 18, 2004

plinth - I have one of those systems (a gatco, actually) and I really like the V-shaped stone for serrations. The stones feel really soft, though. Very easy to (learn to) sharpen knives well with those kits.

Personally, though, using a large stone just feels more gratifying.
posted by PurplePorpoise at 1:49 PM on December 18, 2004

I recommend reading Knife Maintenance and Sharpening by Chad Ward over at eGullet. It's the best treatise on knife care I've seen.
posted by mendel at 5:07 PM on December 18, 2004 [2 favorites]

You know, I've had a Lansky system for some time. I've used it on my chef's knife, but I notice that the nature of the system seems to result in a large variation in sharpening angle from center to edge. It's quite obvious looking at the finished job--you used to have a nice even bevel and you now have these extra wide bevel surfaces (= thinner angle). Anyone else notice this?
posted by RikiTikiTavi at 10:38 PM on December 18, 2004

mendel, that site is awesome. Thanks.
posted by caddis at 10:40 PM on December 18, 2004

Crikey.

Thanks mendel.
posted by dash_slot- at 4:40 AM on December 19, 2004

You may also have worsened your problem by trying all three. The disk sharpener will give it a very slight concave edge, the rod sharpener will give it a perfect V, and the steel, if not done perfectly, will give it an inconsistent V-ish shape perhaps with some concave. So if you try all three in a row you probably rounded your edge...
posted by stp123 at 7:57 AM on December 19, 2004

RikiTikiTavi - instead of clamping in the middle of the knife (especiallty with larger knives), clamp it 1/3 from the tip, sharpen the front halt, reclamp 1/3 from the hilt, sharpen the back half. Maybe finish it with a fine grit diamond.

Sure it takes a little practice to use a stone effectively, but it's worth it. Kits are really useful for convenience, but the end result might not be as great.
posted by PurplePorpoise at 11:18 AM on December 19, 2004

Mendel, that link is worthy of an FPP. I'm serious, great stuff.
posted by wolftrouble at 5:41 PM on December 19, 2004