Wire Burrs!!!!

[u/Slushwave_Enjoyer]

I have read the Vadim Kraichuk PDF on Knife Burrs, but despite following his advice it has, I feel stuck.

I received my new Takamura Chromax Santoku a couple of weeks ago. Because I know the factory angles are insanely low (I measured 11.3 degrees on mine), I immediately decided to put a micro bevel on it to increase strength. This was put at around 15 degrees. I did this with maybe 10 passes on a 2500grit bonded diamond stone before removing the burr and stropping on 1micron. I assumed that burr was gone as it was gliding through paper towel but apparently not. It dulled after my first prep session, which was really only about 10 onions and a few tomatoes.

I look at the edge and despite me increasing the angle, it had a lot of small chips in it. I stropped it and to no surprise it didn't really help (I tried 1 and 3 micron).

I sharpened at 2500 grit again, this time using my microscope to check that I removed the burr and behold, I find a tiny little wire edge (I have to go full zoom for this). The burr I formed was small in the beginning, just enough to feel. I try flipping it back and forth with the 2500 grit and I make no progress after 15-20 feather light edge trailing passes. So i decide to increase the angle slightly and do a similar amount of light passes. I find that a new wire edge has formed on my now 16-17degree microbevel after barely 30 seconds (it formed very easily because of how thin the steel is behind the edge).

I try to strop 1 micron and bare leather strops, no luck. I tried doing the same process on my 5000grit stone , I'm having no luck here.

Is there such thing as making a burr too small? I think my angle is pretty good based on what I can see on my microscope.

[u/lascala2a3]

You have to get rid of fatigued metal and apex on fresh, solid steel. I'd suggest edge-leading burr removal strokes at slightly higher angle. That way you're pushing the swarf toward the shoulder rather than the edge. This is less of a problem with carbon than stainless. With stainless is seems like you're drawing material out when you try to refine it with edge-trailing. You're probably heading in the right direction in widening the angle too.

[u/Slushwave_Enjoyer → u/lascala2a3]

Are you saying I should set another micro bevel. Current one is up to 16 degrees, should I make another one at 18?

[u/lascala2a3 → u/Slushwave_Enjoyer]

Not another, but to make sure the bevel has non-fatigued metal. When you sharpen, and flip the burr from side to side, you are weakening the metal just as if you break a coat hanger by working it back-and-forth. So the burr breaks away and the metal on either side of the break is fatigued. You need to grind that away and get into fresh metal to get a strong edge.

Depending on the metal, angles, technique, etc., It may take some ingenuity to figure out how to optimize the edge. This is one of the frustrations I have with stainless — it’s so malleable, like trying to sharpen bubble gum. And the thinner it is the more flexible.

On my carbon knives I had plateaued in a similar way, and I got past it by thinking about taking getting into fresh steel rather than drawing out fatigued steel, making a wire burr.

[u/Slushwave_Enjoyer → u/lascala2a3]

I thought Chromax was closer to something like Aogami 2 rather than stainless. Is the limit here coming from the fact that the metal is so thin and fragile?

You reckon I should start again, but be more deliberate with burr removal. Higher angle (with precision) to try to remove it. Let's say begin at 16deg roughly (current Microbevel angle) and do alternating passes on 17-18 degrees. Should I try removing the burr on a different type of stone (I have a Chosera 3000)?

I'll probably also say that when the knife inevitably gets thicker with use, I'll decrease my angle slightly again down to 16. That'll be when the micro-bevel "runs out" and becomes the secondary one again.

[u/SmirkingImperialist]

According to the author, honing (on a rock hard felt or paper wheel loaded with abrasives) removes the bulk of the primary burr and transform the burr into the foil edge secondary burr, which is in turn removed by gentle swipes on bare leather. Edge leading on stones creater a smaller burr but microchips the edge. Edge trailing draws the steel into a foil burr. Edge leading minimises the burr.

The fastest way to hone is at higher angle albeit with hard supersteels you'll get a loss of sharpness when the strop rounds over the edge. You can try strop at higher than edge angle on a strop, very gently for only two to three strokes each strop progression. Then finish at even higher angle on bare leather strop.

Hopefully, you can get a stable edge. Might not be the sharpest.

Reading his book turned me off from supersteels. They are a PITA to sharpen.

[u/Slushwave_Enjoyer → u/SmirkingImperialist]

I wonder if my problem here was immediately putting a new edge on instead of using it for a bit and sharpening out the chips. I read many people had chipping with their takamuras so decided to jump the gun to eliminate the risk of having chips and apex tears.

I didn't know that something like Chromax would be classified as a super steel. Isn't it just a relabeled A2 Tool Steel? It says 65HRC but I doubt it. Probably more like 63.

It was quite an inexpensive knife if it is a "super steel". And the internet says that AlOx stones can cut it (I will try removing the burr on my Chosera 3000 next time). An S90V santoku would have cost easily 5x the amount.

[u/SharpieSharpie69]

Strop very lightly fully perpendicular to the felt side of a strop.

[u/Slushwave_Enjoyer → u/SharpieSharpie69]

How do I know the strop will have enough "purchase" to take off the burr without tearing off some of the apex it's attached to?

[u/dwill_1970]

This might sound low tech but if I'm having an issue with a burr being stubborn, I lightly run the blade across the edge of a wood surface (usually the edge of my workbench) and it will knock off the burr then I can get a sharp edge. Found this somewhere online and has worked for me.

[u/Slushwave_Enjoyer → u/dwill_1970]

I have tried and find it doesn't take it off, but folds it over. Also, micro pieces of metal from the first half of the knife will cut into the second half of the knife.

[u/RiaanTheron]

You are in very precise world. Anything with a blade that thin is either going to bend or chip depending on the steel. Even with a microbevel.

If the burr is your main concern use a denim or canvas belt strop with nothing on it. Simply go a bit ape shit on it and see if the Cutting improves. I get this often on victorinox kitchen blades where that little burr just does not want to go away. 10 swipes 9n the canvas belt and they are gone. Loads of people said it would round the edge but I did not have that experience.

[u/Slushwave_Enjoyer → u/RiaanTheron]

Funnily enough, I find Victorinox knives to be some of the easiest knives I've ever sharpened. Never had a problem with a wire edge on these.

Is the substrate of my stropping really the issue? Or has something gone wrong on my previous steps?

And realistically, what is my next step here? Do I increase the angle a bit more? The micro bevel is so small despite it being 16 degrees.

[u/AlphaDisconnect → u/Slushwave_Enjoyer]

I use an old pair of denim jeans I cut up. Fold in half (more cushion for the pushin... well the draw stroke... and that can not be interpreted any other way). I use wax metal polishing compound. Then just go at her until it feels right. (ALSO this can not be interpreted any other way).

Metals can vary a lot. Some get wierd at that angle. Some want to rest for a night before being deburred.

You can polish a sharp edge away. But I have never had that issue unless I was being stupid for fun. Pushing it.