Hello, I am a knife novice compared to many here. I use an inexpensive Chinese cleaver for 95% of my cooking, and when it gets dull (i.e. when I can see light reflecting from the edge) I sharpen it on a coarse stone I got from WalMart. It's a crude method but it has always worked for me. But recently I've started doing a little more online research into cooking knives and it turns out that what I am doing by using this coarse stone is putting micro serrations into the edge, essentially turning it into a microscopic saw. This makes sense to me as my cleaver is always great with the draw and push cuts after sharpening, although it's never very good with the rock chop. I have a couple questions about this:
1) Will the edge stay sharp longer if polished with sequentially finer grits instead of just using the coarse stone?
2) Is a more polished edge better than a micro-serrated edge for rock chopping?
3) With a finer-finished edge, do you lose draw-cutting ability?
4) What are the benefits/drawbacks to a finely finished edge vs. micro serrations that I am not thinking of?
Thanks for humoring some newbie questions
Not really newbie questions IMO. I've spent some time figuring out the answers to these questions, and there are other experienced sharpeners who might disagree with me.
1) This is the toughest of your questions to answer. In a basic sense, an edge finished at high grit does seem to be somewhat more stable than an edge finished at a coarse grit at the same angle. But functionally, it doesn't always feel that way in use. The reasons for this are complicated. A coarse edge can be imperfect but still aggressively cut into food because of its larger 'teeth.' A finely polished edge can feel very sharp directly off the stones, but extreme sharpness such as the ability to fall through a tomato skin with no sawing movement of the blade at all falls off quickly with use, and the knife can feel comparably dull to a coarser edge after a couple minutes or hours of use post sharpening. But finishing at a higher grit (at least when hand sharpening) does a couple other things - it fixes some imperfections from coarser stones and also often adds a little convexity to the extreme edge. These can function to limit edge failure either from a wire edge (a tiny flap of metal or burr that hasn't been removed) or from the edge folding or being mashed down further down the line. It seems to me that a fine grit sharpening stays longer in that fairly sharp but not super sharp range. Even more complicated, this can depend quite a bit on the knife being sharpened. Some knives hold onto sharpness from a fine grit sharpening much longer than others.
If you're having wire edge issues - if your coarse edges feel significantly less sharp after a very short amount of use - you'll probably benefit greatly from sharpening to a finer grit and also refining your technique for burr removal. If you don't sharpen very often at all, you also might find a somewhat greater degree of overall edge retention from sharpening to a higher grit. If you want a knife to cut aggressively with minimal work on the stones, a coarse finish might be better. But it will likely take a little experimentation to figure out what works best for you.
2) Depends on both your particular rock chopping motion and also what you're cutting. A polished edge is better at push cutting (a cut with no sawing motion), while a coarser edge bites into food more easily while slicing. Some people rock chop with a long stroke which incorporates a lot of slicing motion, while some rock chop with a short or stationary stroke and very little slicing motion. IMO, a fully stationary stroke (no forward-and-backward motion at all) is sub-ideal except for very fine tasks like mincing garlic. In any case, a sharp knife should rock chop well whether it is sharpened to a fine grit or a coarse one, as long as it's sharp. It's not a cut that demands an edge you could shave your face with.
3) Somewhat. Right off the stones, a fine grit edge will often be so sharp that it will cut well with pretty much any stroke. If you maintain that sharpness with frequent touch ups and stropping, then it will continue to cut well. This kind of maintenance strategy is why fine grit edges are popular over at the various knife forums and such. A coarse edge does cut somewhat more aggressively in a draw cut stroke, and this difference is even more pronounced if you let a fine grit edge lose some of that extreme off-the-stones sharpness. Notably, this matters more with fibrous foods (meats, etc) and soft foods with skins (tomatoes) than it does with some other foods.
4) Hopefully I've already covered this question in the admittedly long-winded post above. But a couple things to keep in mind. For one, how fine a grit you should use depends on your preference and cutting technique, but ALSO on your maintenance strategy. If you're steeling on a grooved steel, there's not much point in finishing to a high grit on the stones. If you give your knife a frequent stropping or frequent touch ups on the stones, a fine grit is an option.
Likewise, you might even find a mixed strategy is useful. I personally have a strategy I often employ where I sharpen well on a medium grit stone (usually 2000 grit waterstone), and then jump to 8000 grit for a short while, deliberately not fully polishing out all the scratches from the 2k stone, sometimes adding a one-sided microbevel. I feel this can refine and stabilize the coarser edge while still providing a little of the extra cutting aggression of a coarser edge. I'm trying to mix the benefits of both kinds of edges. Then again, I haven't heard of many other sharpeners doing this kind of thing deliberately.
The take home point might be that, above all, you should experiment a bit and see what kind of edge fits your style best. There is no absolute answer as to which is better.
Hi. Cowboyardee did an awesome job of breaking down what i consider to be some pretty advanced questions. I would agree that there is no one size fits all answer. The knife, user, what you're cutting as well as a host of other variables comes into play. You sort of have to experiment with different edge configurations to determine what works best.
I think cowboyardee pretty much covered the answers.
In my opinion, a lot of the question you asked depending on the circumstances, such as your cutting style and your knife. For example, a high quality benefits much more from a fine polished knife than a low quality knife. In addition, if you are maintaining your knife using a honing rod, then you don't gain much by sharpening to a finer edge because the honing rod will destory it pretty quickly. -- a point which cowboy has nicely made.