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Knife Sharpening Techniques & Skills

 
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sabino
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PostPosted: Wed Oct 06, 2010 4:00 pm    Post subject: Knife Sharpening Techniques & Skills Reply with quote

I am submitting this post at Michael's suggestion, following an email I sent him privately.

I am interested in _and_ writing about knife sharpening;
... an area which has led me to some disappointment, confusion and/or frustration.

I have an assortment of good quality knives (Wusthof, Henkels, F. Dick, MAC) rather than one particular set.
While I do have some DMT Diafold sharpeners, a while back I splurged and bought myself
... three genuine natural 8" x 3" Arkansas Novaculite Sharpening Stones (Medium/Fine/Extra-Fine "Black").
I have both a metal "steel" and a long ceramic stick "steel".

In the past, when I had my knives sharpened professionally I used either of two sources:
- one a small specialty knife dealer, in upstate NY near family I would visit,
- the other a *very* skilled professional sharpening service in Connecticut Holly Manufacturing / Holly Tool & Knife Co, which sadly after years of operation is now closed & gone.
(FWIW - when Holly returned your sharpened knives, you got a brief writeup on its before- & after- condition along with a microscope photo of the blades edge!! )

Anyway, though I live in a major metropolitan area (Balt/Wash), I have found it hard to find a sharpening service that does a truly expert job on my knives.
Even the few companies that supposedly service restaurants have given me inconsistent or mediocre results.
Additionally, it seems there are fewer real tradesmen or craftsmen in this field full time now.

The next step for me was to try to learn to do it myself manually (meaning without using expensive equipment or machines).
I read a bit on the topic, watched quite a few online videos, and talked to local shops as well as chefs.
What I found was a LOT of confusion and inconsistency ... not to mention some obvious flat-out misinformation.
Even among otherwise knowledgeable & respected sources, for example, there was contradiction and lack of consensus about in which direction to sharpen a blade
____ (drawing it INTO the edge _or_ AWAY FROM the edge)

Some were adamant about one, some strongly favored the other direction, and some said either was correct or OK !! ?? hmmmm

Most though seemed to agree, sharpen in one direction only.
Yet ...I spoke to a few professionals (chefs, butchers) who sharpen their own blades using BOTH directions (going back n forth) !! ?? WTF @#$%^&

ANOTHER ISSUE
As long as you stick to *one choice*, does it really matter whether you use oil _versus_ water ?

MAJOR ISSUE
Learning how to consistently hold the proper angle while sharpening on a stone has been a real frustrating skill or variable for me. Heck the difference between 18 and 22 is not that easy to see and learn to hold, even when I bring out a protractor. Yet it can make a BIG difference in the final result. I was hoping to be able to use the high quality (and costly) stones I already have without having to buy new systems like GATCO, or Lansky or Edge Pro.

Such are the questions and info I'd like to better understand & master.

I already know that there are almost as many opinions as there are persons asked. And this may lead to more unresolved discussion, but...
I thought there was a thoroughness & sensibility to this group that might help us see if there are any areas we can collective arrive at some consensus about.

Do you have any info or advise you can share ?
What advice can you offer on... how to learn good sharpening skills without someone at hand to help point out or correct mistakes and bad habits ?
.
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Dilbert



Joined: 19 Oct 2007
Posts: 1018
Location: central PA

PostPosted: Wed Oct 06, 2010 6:21 pm    Post subject: Reply with quote

ah,,, nothing like the ole' 'how to sharpen a knife' debate (g)

I think first one has to separate things into the "usual and customary user" vs. the "extremist/perfectionist" camp. "sharp" is not an absolute term or definition - so while some insist on the ability to shave the hair off one's arm - I personally don't use my kitchen knives for shaving.....so I don't go there.

that said, there are tasks where razor sharpness is required - no question in my mind that a sushi chef would find my (freshly sharpened) kitchen knives inadequate to his task of artfully coming up with paper thin slices . . . . they will however, easily & cleanly slice up a roasted chicken breast; and I can neatly skin a salmon fillet without much fuss.

oil vs. water: my understanding is the oil stones retain the grinding swarf particles and clog up. okay, need to be "cleaned" now and then. the finer the 'grit' the more readily they clog. using multi-thousand grit stones, perhaps more common in sharpening very hard Asian style knives, benefit from water - hence the "water stone"

in a "hand sharpening" scenario, it's unlikely that there's a significant difference in lubrication effects regards de-tempering the blade edge.

(psst: don't tell anybody, but I don't use oil or water. I just sharpen them "dry" . . . )

so far as "learning" the "how" of the desired angle - very simple: sine = opposite over hypotenuse. multiple the width of the blade by the sine of the angle, that's how high off the stone to hold the blade. now, easy to say, more difficult to physically achieve in practice. and practice is the key word. a "pro" sharpening scores of knives every day is much more practiced at free-handing the angle. I do one or two knives every four to six months - it's a struggle.....

I have also given consideration to buying one of the gadget systems. if one cobbles up a method to hard mount the Gatco, it's functionally similar to the higher end "systems" - a fixed angle jig is very attractive.

but I'm still free-handing; cut a plastic 'guide' I tacked onto my tri-stone fixture - gives me a constant 15' reference at every stroke. the other thing I found hugely helpful is the black felt tip marker "paint" on the cutting edge - that and a 10x loupe you can visually "see" where you are on the angle and in the process of establishing a good edge.

do I manage an absolute consistent angle? I'd say not. does it work in reality? yup.

I would add - I use a steel at pretty much every use to maintain an edge, and I don't wait until the knife won't cut butter anymore before I take it to a stone. most times I only need/use the 'fine' stone (1000 grit, more or less) - I typically only need the medium grit stone to re-establish a point on the tip. typically takes 4-5 minutes per knife on 'fine' to put things to right. the only time I've used the coarse stone is when a dear child broke off the tip of a paring knife and I had to completely re-profile the last 2 inches of the knife . . .

so far as strokes "into" the edge or "away from" the edge - I always stroke into the edge. I think the away stroke method is more applicable when using super fine grit - razor sharp - polishing stuff. stroking away from the edge will "raise a wire edge" - you may have encountered that term - that's where the very finest point of the cutting edge gets so thin it "rolls up" - a steel is used to remove the wire edge leaving just the razor edge bit.

the other debate on the degree of grit fine-ness is: "micron thickness cutting edge" vs. "micro-serrated cutting edge." looking at the edge under 10x - at the 1000 grit level you'll see tiny serrations due to the cutting action being perpendicular to the edge. the serrations eventually "go away" with use of the steel as that motion is largely parallel to the cutting edge.

"large serration" ala Cutco make for a tearing effect. finer, I think, creates not macro tearing - perhaps micro-tearing - but end effect, easier cutting effort. finer and finer micro serrations eventual lead to the no-tearing-at-all-micron-thickness comfy shave yo- face cutting edge. aside from the angle of the edge, seems to me there's a region of "don't work too good" between micro-serrations and micron-thickness-edges. just my experience.
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buttered popcorn



Joined: 01 Oct 2010
Posts: 6

PostPosted: Sat Oct 09, 2010 6:48 pm    Post subject: Sharpening Reply with quote

Sometimes, it is the knife and not the operator . If a knife is hard, it will be hard to re-sharpen. I now use carbon steel which I am happy with, but before I went insane trying to get an edge on my Global's. It took forever with stones. It was not much fun when a knife got dull, and I refused to ship them out at $7 a pop. My husband is my best friend, but he did not want to know about it ( he eventually got me my carbon babies ) . I am a former pro chef and really talked with people about this and in the end, felt the knives were just to hard. I spend a tenth of the time on my carbon babies now, and feel empowered instead of frustrated ( those globals cost a lot and are now my sisters headache ) .
I use a steel, which is new and the key is to make sure not to grind off the edge. Sharpen,pluck.
I learned in cooking school that to use a magic marker on the edge - a thin tiny line on either side. We were told to stroke stroke and check the line, then pluck. When the line was removed, it was sharp. He alos taught us to pluck a sharp knife and remember what it felt like. Hope this helps.
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