how do i romve a wire burr?

B

bronyblacksmith

Joined
Nov 6, 2012
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i have been sharpening on my norton stone (320 grit) and can feel a wire burr on the edge i have tried using steels to remove it and stropping to remove it but that just pushes it to one side how do i remove it?
 
This might indicate the steel is very soft. Perhaps you might try placing a seet of 8oo sandpaper on a flat surface, holding the knife at approximately a 22degree angle on each side and drawing the knife towards yourself. Frank
 
Frank made a good point; how hard is the edge if it won't come off on a steel. 320 grit is rough; good to make the initial edge, but to rough as a finish grit. Take to 600 and then strop. Cardboard is one of the best strops. A little green rouge on it; use pressure.
 
A couple of strokes on a rouge charged leather strop should remove it. A quick pass on each side on a 6" fine muslin buff charged with white rouge will, too ( do this only if you are very familliar with buffers).

After the stropping/buffing, a couple of cuts through heavy card stock or shirt cardboard is always a good idea.
 
Another thing that works great is to take a piece of scrap wood and drag the edge of the knife on the edge of it as if you were trying to slice into it. Don't do it too hard but do just a few slices and that really helps. It works best if you do it while you're up in the higher grits of w/e you use, (ten swipes on the stone, then a few slices on the wood, then repeat) and then go to stropping. Hope this helps :)

-Paul
 
Better heat treat and making sure that you are entirely through the decarb before sharpening

-Page
 
What ever the technique you use, marking the edge before you start sharpening, using a black magic marker, makes the process easier.

Fred
 
Wire-edge formation depends on many variables: chemical elements, ht, bevel angle, abrasive type & backing, etc. Wire-edge on high rc blade actually quite difficult to remove, e.g. spyderco vg-10 knives, zdp-189 knives. Nothing soft about 66-67rc on a spyderco zdp knives. Any way, check out my video and maybe give my method a shot.

Freehand Knife Sharpening burr & wire-edge removal
http://youtu.be/l2ynSDYEUYI
 
I see so many people sharpening dry, that video included, what you are doing when you sharpen without oil or water is overheating the first couple of microns of your edge ( you know. The part actually doing the work) and taking the hardness right out of it. You will not feel it because you have the thermal mass if the rest of the blade between that and your finger, but Roman Landes has measured it. Always use oil or water as a coolant while sharpening. If you are dry sharpening an otherwise properly heat treated blade just using coolant might be enough to fix the edge softness that is giving you that problem

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sunshadow said:
I see so many people sharpening dry, that video included, what you are doing when you sharpen without oil or water is overheating the first couple of microns of your edge ( you know. The part actually doing the work) and taking the hardness right out of it. You will not feel it because you have the thermal mass if the rest of the blade between that and your finger, but Roman Landes has measured it. Always use oil or water as a coolant while sharpening. If you are dry sharpening an otherwise properly heat treated blade just using coolant might be enough to fix the edge softness that is giving you that problem

-Page
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White back, I read about Roman Landes's experiment where the embedded thermal sensor read over 2000 celcius.

a) if it's true, then most dry-sharpening will resulted with more/less annealed steel edge, therefore such edge would not about to slices cardboard and slice phonebook paper afterward. 0.5um of bad edge won't slice newsprint/phonebook. The video (at the end) shown the knife clearly performed fine.

b) Roman experiment was about stropping/lapping. I am not so sure whether electro-static didn't messed the sensors caused abnormal reading. He didn't addressed thermal accumulation vs diffusion in thin cross section for this manual abrasion experiment. We need more formal studies in this area. Again, straight razors stropping would be negatively affected by this if it is true.
 
I have personally discussed Roman's research and findings from this experiment with him at Ashokan the evening he presented it there, his research in that area was sharpening on fine stones. The annealing effect was only a couple of microns deep, beyond that the thermal mass of the blade absorbed the energy. As a former metallurgical associate engineer who used to spend hours looking at metal phases and thermal effects under microscopes, what he described made sense, and I did some experiments dry sharpening and wet sharpening identical blades made of 1084 when I got home, and found that the dry sharpened blade developed a wire edge (deformation burr) where the wet sharpened edge felt harder on the diamond stones, and did not develop a burr, and was starting to shave hairs off my arm at the end of the blue DMT stone step, while the dry sharpened one developed a nasty wire edge that would grab and cut aggressively for a short time on the red stone, then after doing the burr removal thing would cut as a toothy edge at cardboard and paper etc, but not as cleanly and for nowhere near as long as the wet sharpened edge. You can do what you choose, and if your choice is to sharpen dry, so be it. Personally my money is on Roman's research. Once his book is available in English I will be buying a copy.

-Page
 
sunshadow said:
I have personally discussed Roman's research and findings from this experiment with him at Ashokan the evening he presented it there, his research in that area was sharpening on fine stones. The annealing effect was only a couple of microns deep, beyond that the thermal mass of the blade absorbed the energy. As a former metallurgical associate engineer who used to spend hours looking at metal phases and thermal effects under microscopes, what he described made sense, and I did some experiments dry sharpening and wet sharpening identical blades made of 1084 when I got home, and found that the dry sharpened blade developed a wire edge (deformation burr) where the wet sharpened edge felt harder on the diamond stones, and did not develop a burr, and was starting to shave hairs off my arm at the end of the blue DMT stone step, while the dry sharpened one developed a nasty wire edge that would grab and cut aggressively for a short time on the red stone, then after doing the burr removal thing would cut as a toothy edge at cardboard and paper etc, but not as cleanly and for nowhere near as long as the wet sharpened edge. You can do what you choose, and if your choice is to sharpen dry, so be it. Personally my money is on Roman's research. Once his book is available in English I will be buying a copy.

-Page
Click to expand...
Yes, I would buy an English translation of Roman's book too. Sadly not big enough market for it.

Wet sharpening on fixed-abrasive surface yields higher resistance from abrading, mostly because blade interacts 90%+ to hard/fixed abrasives. Wet swarf on diamond plate either wash away and clogged. While dry swarf induces higher percentage of ball-bearing (lapping) affect, thus easier to develop burr & wire-edge and also feel less resistance. I used edge-leading on dry clean stone/plate which minimize burr formation. And btw with waterstones, I mostly use with water but sometime dry for lapping/polishing affect.

Again if Roman is right, 2um of ruined edge would render most dry sharpening useless. Extrapolate to sharpening by dry belt/wheel/disc/power, bad steel layer must be thick (even for hss):confused: Do most knife markers hand wet-sharpen production knives?
 
most production knives have an edge cross section of 2-5 microns, sometimes thicker if they are using steels which have blocky carbide formers (some of the high chromium steels for instance) they would likely not notice much difference. Apparently further argument is pointless, some people continue to believe that the earth is flat too. I choose to believe an Aerospace metallurgist who by day works in the lab of some of the most highly regarded engine manufacturers in Germany whose results I have to some extent replicated empirically. Have a nice day.

-Page
 
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