What combination of sharpening gear?

Very interesting. Ice Bear stones are quite wide so I got lucky there.

I just recalibrated the thread/scale combo I use again and the force necessary for a Bic razor is 30-50! Odd! My theory is that the razor I picked yesterday was flawed. I noticed a coating of material on it that I hadn't noticed on others, no idea what it was. The Opinel is now hovering at 150 grams as I resharpened it and rather sloppily. The bevels are totally uneven now because of my laziness. I know I can do better if I concentrate on what I'm doing.

I'm not getting a consistent edge across the entire blade though.

Do I just need practice? Is it simply that I'm doing it unevenly?

Should I be happy if I can get an Opinel down to 50 grams force? :eek: I notice there is an extremely noticeable difference in sharpness from 50 grams to 100 grams.

Another question: should I keep my fingers on the blade or on the handle when I'm sharpening (probably makes a difference between folders and fixed?) and should I disperse the fingers evenly across the blade? How hard should I be pressing on the stone? Right now I'm doing it with quite some force.

Sorry for all the questions, and thanks!
 
Ideally sharpening would consist of pure abrasion of the stone on the metal, however there is always distortion due to pressure and worse yet the distortion is always from one side which pushes the edge off center. To minimize the distortion you have to reduce the force, when you are shaping you press really hard but when honing the final edge you should back off a lot. The final few passes are really light in general and you want a really clean hone.

Angle control makes a huge difference as well, many times to one. If you use a jig you eliminate one of the major sources of frustration because all the passes above the edge angle don't induce any honing at all, they are just reshaping the edge, plus if you accidently make even one pass at a really highly angle, now nothing does any honing until that micro-bevel is removed. It is very time consuming to remove a burr with a high angle variance.

If you can get an Opinel as sharp as most disposable razor blades then that is indeed very sharp, very few knives come this sharp.

-Cliff
 
How do I know I'm forming a bur on a waterstone? I can neither see nor feel the burr, does this simply mean I'm not forming one?

Edit: NM, I JUST got a burr after quite some work. Thats the first time I've gotten a burr using a waterstone, then I took the burr off on the 10k stone.

I now have two theories as to why it isn't sharper then it is.

1: Grit contamination on all stones. In my excitement over forming a burr (inspired by watching a Hock Blades video online where he says to get a sharp edge you must form a burr on a waterstone, then move up a grade, knock it off and form a new one etc.) I did not clean them or the blade and there was very noticeable grit contamination.

2: I did not form a burr on the 10k, nor did I use a 4k in between forming a burr on the 1k and moving to the 10k, so the scratches were slightly larger.

On the upside it is now at 150 grams force, wheras before I attempted to form a burr it was over 300. I'm still trying to figure out how I got 100 before...

Edit:
Woot woot!
12 o clock tonight almost exactly, and I got it down to 75 with some very precise microbeveling with the 3m paper. On 2/3rds of the blade it is down to 50 grams!!!! :):)

I looked at it under my cheesy microscope and the microbevel is perfectly even across the blade, with absolutely no nicks in it. I wiped down the 3m paper with a baby oil impregnated paper towel before use to eliminate cross abrasive contamination.
 
One of the benefits to measuring sharpness in some quantitative manner is that it takes a lot of the guesswork out of method because you see concretely if the sharpness has improved and more importantly by how much. If you start doing edge retention comparisons this becomes even more important because a really nice sharpening job on a average steel can allow it to readily outperform an average sharpening job on a very high end steel.

Some steels don't burr that heavily, it depends on their condition as well. For example if after a cardboard run which blunts an edge down to say 5% of optimal sharpness I take blades to the 200 grit silicon carbide stone, most steels will now form a large burr which is even visible and if you wipe it on your pant leg for example, it works like a scraper and collects fabric debris like crazy. The steel in the highly blunted state is really deformed and weakened and bends too easily under the stone.

However if you are sharpening lightly used knives, you may not see a heavy burr on fine grained and very hard steels. In that case you need to insure that every stage of sharpening leaves the blade very sharp, at a minimum slice newsprint very smoothly with no tearing, and very far from where it is being held (several inches). Ideally it should push cut at 90 at least one inch from the point it is being held, but that is not easy to do.

-Cliff
 
Yes, I was reprofiling a cheap kitchen knife on my new silicon carbide super rough Norton reprofiling stone and a massive burr appeared as well.

One of the benefits to measuring sharpness in some quantitative manner is that it takes a lot of the guesswork out of method because you see concretely if the sharpness has improved and more importantly by how much. If you start doing edge retention comparisons this becomes even more important because a really nice sharpening job on a average steel can allow it to readily outperform an average sharpening job on a very high end steel.
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Absolutely. If I hadn't seen your poly thread comparisons it would have taken me a long, long time to get a knife this sharp.

However if you are sharpening lightly used knives, you may not see a heavy burr on fine grained and very hard steels. In that case you need to insure that every stage of sharpening leaves the blade very sharp, at a minimum slice newsprint very smoothly with no tearing, and very far from where it is being held (several inches). Ideally it should push cut at 90 at least one inch from the point it is being held, but that is not easy to do.
Click to expand...

Ok... I don't think I can do that! The most standoff I can achieve between where the blade push cuts and where I'm holding it is about one centimeter in newspaper. I think perhaps at this point its more a matter of skill at this and entire blade geometry no?

Honestly while poly thread testing at 10 random points of the edge seems tedious, I like it because it is nearly independent of user skill. Although I like push cutting newsprint because now it feels like slicing through air!
 
Paper cutting is nice because it is easy to do and available to anyone, but it is really easy to cheat and tilt the blade a little, or use a bit of a draw, or let the paper fold a little and still call it a clean cut, then numbers on the thread or cotton don't lie though. If you really want to see impressive sharpness do a search for some of the cutting Fikes has done in live demonstrations. There is a lot more to doing the cuts of course than a sharp blade.

-Cliff
 
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