Super polished edges

Larrin

Larrin

Joined
Jan 17, 2004
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What do you find is the easiest way to get a super polished edge?

DMT's ceramic is rated at 7 micron or 2200 mesh, but few other companies give a grit other than "extra fine." Are there ceramic rods/sharpeners that are any finer?

It seems that the very sharpest edges have to be gotten either through very high grit Japanese waterstones, or through a fine paste (diamond, chromium oxide, etc.) on a strop. What are your favorite polishing pastes, and what is your favorite strop? I've heard everything from just plain leather to cardboard and leather wheels.
 
At a certain point, a polished edge isn't worth the effort. Super polished edges are good for looks - but not so much for cutting.

Once you use toothpaste for your edge - and it does work - that's about as far as I would think to go. Yes, you CAN go finer - strop the blade on glass - but there is little point.
 
I sharpen my knives on a very fine hard arkansas stone, then I strop with a wide strip of leather nailed on a board. I loaded it with some flitz, and it makes my edges like mirrors. Not necessary all the time, but fun.:thumbup:
 
Stopping (cardboard) with metal polish (Flitz) is what I do. But I find that a more course edge is superior for real world cutting.
 
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Draconian said:
At a certain point, a polished edge isn't worth the effort. Super polished edges are good for looks - but not so much for cutting.
Click to expand...

If you are push cutting then you generally see a direct performance in both initial sharpness and edge retention with higher polishes.

I generally finish on either 1200 DMT, fine ceramic, fine waterstone, or black hard arkansas and follow by 0.5 micron chromium/aluminum oxide on very stiff leather or paper on wood/glass and then plain paper.

Ideally I would use the shapton really find stones followed if necessary by diamond or boron carbide sub micron. Or just give the blade to Clark and ask him to sharpen it.

Jeff has described in great detail various methods he has used to obtain extremely high polished edges, others with similar extreme viewpoints on sharpness are Me2, Martin, Landes and Johnston.

-Cliff
 
I used to go up to 2000 grit paper on a mousepad....

It wasn't ROUGH enough to cut good.

I went down to 800 and its like a razor.
 
Edge Pro has a #3000 tape, for a working edge on Case CV I usually just go to the Edge Pro 'Ultra Fine' which IIRC is about #600 and then use a #1200 ceramic steel. I dont really see much(long term) performance benefits with going above #600 even though the time it takes is minimal on a small bladed knife.
 
A superfine synthetic ruby stone will probably polish an edge as bright as you can get it. They are pretty expensive, but they don't wear out like waterstones. I have had one for 25 years or so, but I seldom use it anymore.
Bill
 
I go up to the Shapton 15,000 grit waterstone on my favorite knives (mostly little chip carving knives or hand made Japanese kitchen knives) and maybe strop a little on some 3M 0.3 micron AlO film.

Here's a rough guide to micron sizes for various JIS grits (you can see that Norton's waterstones are rated a grit size or two over what they should be going by thier stated micron sizes, but then the binder also influences the final finish)
Grit chart
 
I have the Edge pro and can use the polishing tapes. Up to 3000 I believe. I also have all 3 spyderco bench stones. Medium, fine and ultra fine which get way up there I believe. I bought some Black-Diamond from thombrogan which I use loaded into a leather strop and have had EXCELLENT success with. Just a few swipes make a noticeable difference on push cutting standard weight computer paper.

I've defintely got the super polishes down. I need a super low grit now to try on a knife. I think I'm going to put a DMT XX coarse edge on a ZDP delica at the same angle as my current EDC one, which is highly polished, to see more of the properties of this metal. I'm willing to bet it will be a folding chainsaw.
 
I have been trialling DMT's 1200 diamond followed by their ceramic and although the ceramic sounds like it is still quite course my knives have been performing well cutting fresh beef. I did find they both take a long time to wear in though. The edge doesn't feel as smooth as when a black Arkansas is used, but I have found that unless the Arkansas is freshly resurfaced it is very slow and tends to round the edge if you are not careful, I am not having this problem with the ceramic. A few strokes on my steel and the edge soon smooths out anyway.
 
My most recent polished edge involved a 1200x DMT to remove scratches, a Norton 8000x waterstone to shine the heck out of everything, and 0.5 micron Norton diamond on film over glass for my sharpest edge that didn't involve power-tools or an EdgePro.
 
Use a lansky up to the super-fine stones (yellow holder, white stone). Don't have the sapphire though.

Then I took glossy reciept paper, attached a strip over the working side of the stone using an elastic at either end, and loaded with 0.5 micron paste. That way I had a very flat, very fine strop that would not give, and that would not change angle.

at 30 degrees inclusive, I can shave face hair with minimal pulling. I want to make a better clamping system for my lansky stones so I can reliably put on a 7-10 degree relief grind, with just a small 10-12 degree microbevel. I'll work on it.

As is though, super polished, push cuts toilet paper, just a little thick to be great.
 
I found some 2micron wet/dry paper, I think this cuts the burrs off better the a strop so leaves a more even edge, it's a big jump for the fine stones on the sharpmaker so I'd guess the edge isn't as polished as it could be
 
Cliff Stamp said:
What type?

-Cliff
Click to expand...

Cheapie one-ply. Wouldn't touch the quilted stuff when I tried that.

That said, it's the first blade I've had that will do one-ply, so I'm kinda happy.
 
That's impressive, I have not seen it to date. I don't use high polishes much but will be seeing how far I can go with some push cutting edge retention work shortly.

-Cliff
 
Wow, Cliff called my view of sharpness extreme. I'm gonna write this on a calender. I find that for my purposes, admittedly not that extreme, I prefer a high polish now. I used to use a final honing w/ Norton Fine India, but I seemed to have to touch up my blades every 2-3 days. My final step is stropping on leather loaded w/ white buffing compound on a 1x30 belt sander. My EDC blades will typically whittle hair from my chin now relatively easily, and from my wife's hair brush with a little difficulty. I also find that my Kershaw Vapor II (the small one) and my Old Timer peanut slipjoint hold this edge for a long time, barring abuse or corrosion for the Old Timer. My Benchmade TSEK seems to hold it for quite a while as well, but seems to dull a little faster through small chipping than the other 2 knives. Of course the TSEK is a much bigger blade, and I may just be subjecting it to rougher use. The edge may also be at too low an angle for my normal use. The edges on the Vapor and TSEK are also so shallow that the thumb studs need to be removed to prevent damage. I would guess somewhere in the 15 degree range, since the 15 degree sharpmaker slots cannot be used for a true microbevel. This loaded leather stropped edge seems to be superior to the white fine rod edge from the sharpmaker, in terms of edge holding. The sharpmaker edge will also shave hair in the above described fashion. This has only really been tested on the Old Timer.
 
The standard Spyderco Sharpmaker setup comes with "medium" and "fine" rated rods. I find that for slicing work the medium rods leave a very effective cutting surface. For kitchen utility work which is a mix of slicing and push cutting the fine rods leave just about an optimum edge finish. I was surprised when I bought a couple Sharpmaker "ultra fine" rods that they did improve shaving and push cutting sharpness significantly over the fine rods. My experience is that the edge finish is finer than you would expect from grit ratings. Ceramic rod grit rating is a misnomer anyway. They generally start with a relatively coarse grit and fire it to the finish that they want. The grit is fused in a way that doesn't match the microstructure of other hones. You kind of need to try them to judge how they work in practice.

To go beyond the ultra fine Spyderco rods I have my best luck stropping on a relatively stiff surface with submicron diamond grit. I use something like a pad of paper to support a sheet of photo paper or plastic view graph material. I strop with almost no pressure so that the strop does not wrap around and increase the edge angle. The diamond grit will cut any variety of steel for a razor finish on even bad stainless.
 
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