Originally posted by Brenjen
Get a Lansky knife sharpening kit with the diamond stones. It will not only put a razor edge on a knife, it will put an edge that looks better than the factory edge.
The Lansky (and Gatco) operate on the same priciple as the edgepro. The difference is in the length of blade which can be sharpened. The former are great for pocket knives and blades 5" or less, but for an 8" chef's knife repositioning is required.
Not that you can't use one (I have), but you sharpen the knife differently each time because of having to reposition the guide. Also, once you have a portion 'razor sharp', its not hard to cut yourself tinkering with moving that guide. The edgepro's claim to fame, imo, is that it can sharpen an eight or 10 inch kitchen knife without repositioning. Be nice if they made something like that for swords.
As a kid I bought a Lo-Ray sharpener at a gun show for pocket knives. It's the same as a Lansky or Gatco but has lasted over 30 years. I think Lansky bought out Lo-Ray, or the patent expired. I've given the Lansky sharpener kits for xmas before, which I though was a very nice gift.
As a bit of trivia, having a knife 'razor sharp' is a common term, but most knives are not as sharp as a razor. I guess the the idea of shaving the hairs on your arm is where that description comes from. A razor, on the other hand can cut a free hair by touching it to the blade. A sharp razor can cut a free thin hair from your head. I found this out when learning to sharpen and shave with a straight razor.
The idea behind using a steel, or the ceramic crock sticks is to reposition the edge, much like stropping a straight razor. Neither device changes the edge profile or removes much metal (if any). In fact, a leather strop could be used for the same purpose except it's not so convenient around the kitchen and takes slightly more skill to keep from cutting it to pieces. Also, the knife is drawn on the leather away from the edge for obvious reasons.
Part of the degree of sharpness, and how long it stays sharp, is the degree of edge finish smoothness. Buffing and polishing is one way to get an edge to last longer. A straight razor has an extremely high degree of smoothness (< 1 micron) while a kitchen knife may be 20-200 microns. A sharp smooth edge will remain sharp longer and can easily be 'touched up', but it's also easier to damage the edge. That's where knowing how to use the knife is important to not damage the edge.
As an aside, something like a hatchet or an axe which is normally sharpened with a file will stay sharp longer if the edge is smooth and polished. That's typically not done, but I've used a Lansky sharpener thru the finest stone on a hatchet with good results. However, the less expensive hand tools generally have soft steel and dull quickly.
One critical part of knife sharpening not mentioned is the type of steel used. A steel with Rockwell hardness C scale (Rc) less than 40 will not hold an edge long. However, it will be easy to sharpen. Personally, I don't keep knives made of soft steel because they constantly require resharpening.
Regards,
Malta