New favorite edge and tecnique

V

Vegas Blade

Joined
Feb 9, 2012
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I posted this in another post, but I thought I'd make a new post and share my experience. This is my latest experiment with S110V, and it's leading to unbelievably sharp knives. I have about 5 different S110V knives, and this is what I've been doing.

Lately, I have been working with S110V. This is my new fun steel. I have been playing around with this technique and getting fantastic results: I set my Wicked Edge to 18DPD. I take the steel through the gamut of 100grit, all the way to .5 micron diamond paste on a leather strop. That puts a beautiful, shiny, read the newspaper edge on the S110V. Then I take the Sharpmaker with the brown stones and run it on the edge about 4-6x each side. According to my Angle Cube, my Sharpmaker is set at 22.5DPS. So I get a mirror main edge with a 22.5DPS micro bevel. This edge is the absolute best edge I've ever achieved on any steel. The S110V should hold it for a VERY long time. Then, 4-6 passes on the Sharpmaker brings it right back. The grit on the brown stones of the Sharpmaker runs around 600-800. Nice "tooth", but still will push cut receipt paper.

I've never been much on micro edges, but I've been playing with the above with fantastic results. My thoughts are that as the edge cuts through, there should be very little friction as the material is being sliced. Once the teeth do there job, the super polished primary edge allows the material to slide off virtually friction free.

Just a little something I've been playing with. S110V seems like a great candidate due to the monstrous edge holding.
 
This is very interesting to me.

Last week I sharpened my Native 5 sprint run with an S110V blade on my Wicked Edge at 20* per side.

I run a Lowes paint stirrer along the edge between grits to break off any burr and to test "sharpness".

I noticed that it felt like it cut into the wood deeper and easier after the 600 grit than it did after 1600 grit.

Yes the edge polished up but I went back over the edge with the 800 grit after the 1600 grit to give the edge more "bite"

Next time I sharpen this knife or my Manix with S110V I'll definitely try your method.

It's funny because the reason I choose 20* per side was so I could do touch ups on my Sharpmaker. I'll drop the Wicked Edge to 18* per side and try your micro bevel idea. I wish I'd thought of that myself.

Good job!
 
With the monstrous amount of carbides in S110V, it should be a steel that holds a toothy edge dang near forever. This Fe content of the steel is like 65%, meaning the carbides are the other 35%. Im sure everyone knows that, but this is just my line of thinking: to keep the friction past the cut minimized, yet let those monster carbides work. Im very, very impressed so far. The edge looks beautiful, but that micro bites deep.

Ive not been a micro edge user before, but this idea seems valid.

Aquaman67, thank you for your kind words. I sure think you'd enjoy the edge. It both looks beautiful, and it plays into the strength of the S110V properties.
 
Vegas,

There are significant benefits to separating the shaping of the edge-bevel (the part you did on the WE) and setting the apex with a micro-bevel (the part you did with the Sharpmaker). The increase in angle and low number of passes used make it much more likely to cut-off any burr formed when shaping the edge-bevel, and make it easier to achieve a clean, crisp, burr free apex. This is also helped by using a solid sintered abrasive which, unlike a friable abrasive (e.g. Japanese waterstones) won't release grit into a slurry that slams into the apex, rounding it over as you sharpen with edge-leading strokes. This also makes it easier to get a clean, burr free, sharp apex.

For knives I want to sharpen quickly, I will often cut off the existing apex with a couple of very light passes into a 1k stone (as if trying to saw the stone in half) until the edge reflects light from a directed light source, shape the edge-bevel on a 1k waterstone at ~6-8 degrees per side until it no longer reflects light, and then set an apex with 5-10 passes per side on Spyderco M rods at the 15 degree per side setting. I usually get an apex that will push-cut phone-book paper across the grain at 90 degrees, shave, etc, while still having a decent amount of slicing aggression.

The second thing to note is that the Spyderco medium rods behave significantly finer than the particle size given for the abrasive due to the relatively shallow cut depth they produce and how quickly the abrasive rounds over slightly. This will result in a more push-cutting oriented apex than you would normally expect
 
Jamesh Bond said:
Curious.

Why take the edge to such a high polish just to put a coarse microbevel on it ?

Thx.
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As I posted above - I could tell a big difference between a 600 grit edge and a 1600 grit edge.

The 600 grit edge felt like it was cutting into a paint stirrer.

At 1600 grit the knife felt like it was just sliding across the wood and not cutting it. It felt "slick" if that makes sense. It had no bite.

That's why I went back to an 800 grit after I finished with the 1600.
 
As aquaman67 said, I too find a highly polished edge too 'slick' with no 'bite'.

The more coarse micro bevel bites better while the polished primary bevel lets the parting material slide by effortlessly.
 
^^^^ This. Due to the huge carbide volume of S110V, it does better with a toothy edge. The reasoning behind this sharpening method is that you get the benefit of the toothy carbides at the edge doing their work, while the remainder of the edge is smooth and polished, thus creating a friction free surface for the material being cut to pass by. This edge also has the advantage of being able to touch up in about 5 passes on the brown Sharpmaker stones. Super easy, super efficient. You're letting the vanadium carbides do their job, yet the surface is friction free past the cut.
 
Damned interesting thread.

Do you guys think this Blade apex geometry will work only with über-high carbide steel like s110v only? What about lesser carbide steels like 20V or CPM154? Maybe not enough carbide in the metal matrix to microbevel apex to the higher angle?
 
Applying a micro bevel is not uncommon, regardless of steel.

And many prefer a toothy edge over a highly polished one.
 
Yes, i get the toothy edge. And agree.

And i get the microbevel. Also agree.

What I'm questioning per the OP, is the need to first take everything to such a high polish when the intention is to then microbevel the final cutting apex to a coarser grit.

Thx.
 
Jamesh Bond said:
What I'm questioning per the OP, is the need to first take everything to such a high polish when the intention is to then microbevel the final cutting apex to a coarser grit.
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And answered in posts 7 and 8.

Also, you get the show-off bling of a mirror finish to flash about while having a more aggressive cutting edge that's nearly invisible.
 
Yeah I do think polished edges are mainly for show... On this very forum people started berating me for having coarse-looking edges on "historic" Lile knives, and I basically told them I didn't have much to learn from people who stick to factory edges... (I could also have told them I can do to my own knives whatever I damn well please, but I tend not to dwell on the obvious to people who have missed it)

Gaston
 
I don't think polished edges are for show... they have their purpose.

and true, I've touched many polished edges that didnt bite, but will carve circles around toothy edges.

It really depends what you're cutting though. I don't cut many hard plastics, mostly cardboard, and polished edges is is so much better.
 
stog75 said:
Do you guys think this Blade apex geometry will work only with über-high carbide steel like s110v only? What about lesser carbide steels like 20V or CPM154? Maybe not enough carbide in the metal matrix to microbevel apex to the higher angle?
Click to expand...

CPM-154 is ~17.5% carbide, S90V is 20% carbide, S110V is 25% carbide. Those are all VERY high carbide. 420HC has ~2% carbide. As already mentioned, a toothy edge before a polished bevel will function the same for any steel - sharp teeth to penetrate the material, a smooth bevel-face to slide on past.
 
As to longevity the more polished edge will out last the toothy edge under same usage conditions.
 
Fred.Rowe said:
As to longevity the more polished edge will out last the toothy edge under same usage conditions.
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mmm... the CATRA results I've seen showed that 600-grit (25 micron) would outlast both 8000-grit (3 micron) and 325 grit (45 micron) - that is cutting abrasive-embedded card-stock. I've seen similar sorts of results on rope - polished edges round-over more quickly, loose their bite, while the toothy edges keep biting longer. *shrug* Carving and chopping, I'd guess the polished edge would win.
 
chiral.grolim said:
mmm... the CATRA results I've seen showed that 600-grit (25 micron) would outlast both 8000-grit (3 micron) and 325 grit (45 micron) - that is cutting abrasive-embedded card-stock. I've seen similar sorts of results on rope - polished edges round-over more quickly, loose their bite, while the toothy edges keep biting longer. *shrug* Carving and chopping, I'd guess the polished edge would win.
Click to expand...

Edges are not a very objective discussion. To many what if's. Its similar to testing the keenness of an edge by shaving one's arm hair. :)
 
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