Home knife sharpening tools
- David Kahn Apr 9, 2008 04:02 PM
I guess I can understand why a professional chef working 12 hours a day, six or seven days a week, wouldn't want to sharpen his or her own knives, particularly if he or she is using a relatively inexpensive stainless steel blade that gets lots of use and is probably replaced every couple of years. In my experience, however, the guys who are using really good, expensive, handmade blades always sharpen them themselves. (I haven't asked him, but I can pretty much guarantee that Chef Urasawa isn't letting anyone else touch, let alone sharpen, any of his beautiful handmade chef's knives.)
Maybe it's just me, but I think knowing how to maintain your tools is an important part of knowing how to use them. Putting a great edge on your own kitchen knives is not difficult, it just takes a little practice, patience, and some time. A set of good ceramic sharpening sticks (like these: http://www.lanskysharpeners.com/LCSGM... or these: http://spyderco.com/catalog/details.p... ) work reasonably well, aren't too expensive, and, unlike the electric grinders that many "professionals" use, there is virtually no possibility that they will ruin your knives by over grinding them or drawing their temper. Or, invest in a set of Japanese waterstones (http://www.japanwoodworker.com/dept.a... ) and learn how to use them. I am willing to bet that you can get a finer, longer lasting edge this way than you'll ever see from somebody you pay to sharpen your knives.
Just my 2¢. I'll get off my soap box now.
I dunno, I have the time, but not the great tools the guy at the shaver shop has. I'll more likely trust my expensive knives to a guy with years of experience than little old me starting out.
Price wise, think of it this way-a knife ruined by an amatuer is more expensive to replace than sharpening service by a pro.
I use Chef's Choice model # 130 sharpener, and am extremely pleased with the results I get. No shlepping, no gas expense, no waiting.
As far as sharpening systems go the EdgePro is one of the best. Not cheap but it cost less than a lot of Japanese knives and it will last a life time. You may have to replace stones on occasion. I have the Apex model and really like it a lot. Near perfect edges from your first attempt.
I was thinking about getting into this. What's better for manual sharpening? Whetstones or ceramic rods? What about my serrated bread knife?
I don't see why a wheel grinder or belt sander wouldn't do the job, but the consequences of error would be worse. Still, you could set up some kind of jig to keep the edge angle correct.
Knives are generally made out of hardened steel. Steel is hardened by heating it up to critical temperature (generally somewhere between 1500F and 1800F, depending on the alloy and carbon content) and then cooling it down rapidly by quenching it in a cooler medium (water, oil, air, etc., again depending on the alloy and carbon content). Once it's hardened, if you heat it up too much, it will lose some or all of its hardness. This softening process is called tempering, and usually begins at around 300F. Generally, the higher the temperature and the longer the duration of exposure, the more hardness is lost. Sometimes tempering is done deliberately because the knifemaker wants to trade off some hardness for increased toughness, but if the steel is tempered too much or at too high a temperature, it will loose too much hardness and no longer hold an edge well. When you use powered tools to sharpen a blade, the friction of the abrasive moving very quickly over a very fine edge can easily overheat the edge and cause it to soften. Depending on the particular steel type, tempering is sometimes accompanied by oxidation which causes the surface color of the metal to change, first to a straw/yellow, then to purple, then to blue, and finally to gray. Over tempering is sometimes called "drawing the temper" of a blade, and depending on how far back from the edge the heat damage extends, the blade can be merely damaged or totally ruined.
When you sharpen something manually, in contrast, the cutting action of the abrasives work much more slowly and don't generally get hot enough for this problem to occur. Another solution to this problem is to use powered equipment in conjunction with some sort of lubricating coolant, like water or oil, but this sort of equipment is probably beyond the reach of most home knife users. (This is how the old-time whetstones worked.) The other problem with powered sharpening equipment is that, even if it doesn't overheat the steel, it can remove a lot of metal very quickly. If not used properly, powered sharpeners can easily over-grind a blade, which can shorten blade life and/or ruin edge geometry. There are a number of good manual sharpening systems out there (a couple of which have been recommended by me and others on this thread), depending on how much one wants to spend and how into sharpening one wants to get. My view, fwiw, is that most people are much better off staying away from powered sharpeners.
So, there you have it -- more than you ever wanted to know or read, I'm sure. I've spent altogether too much time studying this subject because I'm an amateur blacksmith and knifemaker, and this is all stuff one needs to know to produce a good knife. (Some of my work is here: http://rhinoworks.50webs.com/knives.html ).
There are three professional knife sharpeners in the U.S. that I would trust my knives with. So iIlearned how to do it myself from one of those three.
Folks who are interested in learning to sharpen knives might consider starting by purchasing one of these DVD's. They will get a good feel for what it takes (equipment, time, commitment to learning):
Murray Carter has both an Introduction and an Advanced version.
Korin is perhaps the best known. Also look at the info on their site.
For people just starting out cooking, learning good maintenance skills is most important - honing using a steel and finding a trusted local sharpener who knows how to treat a knife (rather than an ice skate). But at some point, as their knife skills get better, some folks want to go beyond that beginner level of sharpness. Learning to sharpen, and having confidence in your own ability to handle expensive steel (without the fear of the local skate sharpener taking chunks out of your new expensive knife) will give you the freedom to try different styles, different steels, different angles - understand how to overcome some of the issues that exist with machine sharpened edges.
I inherited a lansky system sharpening kit and tried it over the winter and it did improve my knife edges, it does a pretty good job of maintaining a consistent angle, I think the very fine stone is important and that was special order, they also claim to have a serrated sharpener as an extra purchase. I just bought the Korin demonstration dvd, a two sided japanese wetstone and began sharpening my western knives, mostly trident wustoff. They are much sharper now. Not sure I can keep a steady angle and still learning, think I damaged the "kanagi" line on a couple knives. All in all, they are much sharper. Bought my first japanese style sushi knife from Korin also, haven't used it yet, looks to be easier to sharpen and maintain though, I'll post back later on that.
Unfortunately, the only way to develop the ability to maintain a consistent angle is practice, which is why it's often suggested that you do so on beater knives. The initial attempt is usually quite bad, but most people pick it up very quickly thereafter.
I think you mean 'shinogi line' rather than 'kanagi line.' The shinogi line is very important for sushi style knives, but it's no big deal for Western style blades. In fact, many people deliberately sharpen out that shinogi line.
Traditional style Japanese seem easier to sharpen because of the very wide primary bevel, but that wide bevel is convex, not flat (just put a straight edge against it and you'll see), so where you place your fingers is really important. Very occasionally, you will also need to sharpen the shinogi line. You need to be carefull here that you don't mess it up. You also need to sharpen/ flatten the back of the knife, but be careful not to destroy the concave back.
Learning how to use a steel without killing your knives is a key . . . there are many videos on this subject on the internet. Basically not just up in the air but putting the tip of the steel onto the cutting board and being consistent with your angle. Personally I like to take a couple of strokes in the reverse direction to straighten any places the edge is bent before starting the normal strokes. (by bent I mean things you can only see under small magnification) Just a regular guy here so I use the steel maybe once a week. I get by with just a 1000 grit water stone and I sharpen . . .er maybe every nine months which is probably overdoing it but I like my knives sharp. I'm told there are two things to consider. . . sharpness and bite. The 1000 grit stone will leave enough bite so you can easily cut a tomato. (bite . . . er mini . . microscopic serration). If I had a chip in a knife or needed to sharpen a serrated bread knife I'd bring it to a pro.
Learn the Lansky system. Not the ceramic sticks, the stones with the clamp. Once you grind an edge the way you want (and it's a bit time consuming because that's what you're there for) keeping the edge is way easier with a steel. Using a steel is not sharpening. Learn to use your tools and learn to maintain them, they are all different and do not expect even a professional to know them all. Besides, it's good therapy.