How Fine a Stone When Deburring a Coarse Edge?

R

rummels

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I have been sharpening a Henckels kitchen knife at 15 degrees per side using a 400 grit diamond stone with edge-trailing strokes. Once the bevel has been re-established, I have been using a 1.4 micron ceramic stone to remove any burrs. The ceramic stone is used at 18 degrees per side with a few very light, edge-leading strokes per side. My goal is to deburr the edge in a way that has a minimum impact on the "toothiness" of the edge.

After each stroke with the ceramic stones, I have been checking the sharpness of edge by lightly pulling my fingertips across the blade in a direction that is perpendicular to the edge. I have noticed that, when I begin deburring and I use the ceramic stone on the right side of the edge, the edge feels sharper to the fingers on my right hand than it does to the fingers on my left hand. I think what is happening is that, when the ceramic stone is first used on the right side of the edge, it pushes the burr over towards the left side of the edge, and the fingertips on my right hand feel the burr more because it is leaning towards the left. The opposite happens when I use a ceramic stone on the left side of the edge.

I continue the alternating, edge-leading strokes with the ceramic stones until the edge feels equally sharp to the fingers on both hands (ie the burr is gone and only the bevel remains). I then do several slicing cuts through newspaper to make sure that I don't have a wire edge.

My first question is whether I should use a coarser stone, like the 3000 grit diamond stones, to deburr so I can reduce the number of strokes required on each side (it currently takes 5-6 strokes per side)? My second question is whether the coarser stone would have a negative impact on the coarseness of the deburred edge?
Any thoughts?
Thanks

rummels
 
Really it'll depend on the steel you're dealing with and how bad of a burr you've got. Use the finest stone that still cleanly removes the burr. I do the exact thing you're describing for producing crisply-apexed toothy edges on scythe blades and jump from an ANSI 120 grit stone to an ANSI 400 (though the stone in question leaves a finish more like a 1k)
 
As Alberta Ed says, a 1200 grit should be fine, one thing you could try to decrease the amount of strokes, increase the angle. you say you are edge leading at 18 degrees, try, a couple of really light strokes at 40-45 degrees and see if that helps.
 
When was the last time you had your hands recalibrated? Snap-on can usually do this for you, but you have to catch them when their truck is on your street. It's a white truck. At least, I think it's white.


















Just kidding. :) Sorry. :) Don't hate me. :) I really need to be banned. Everybody says so. :D
 
You can deburr on that same 400 grit diamond plate. It takes a light touch in some cases, but can usually be done without too much trouble. You might try the "fold over the burr" technique, where you run the blade at almost 90 degrees down a wooden dowel, in order to fold the burr to one side. After doing that, you should have a big pushed over burr on one side, which you then put down on the stone and do careful partial strokes on the plate. Repeat for the other side (fold over the other way, then do the other side on the plate). This should give you the maximum "toothiness" of that plate, since you are never using anything more fine.

Brian.
 
Do as much deburring as you can with the first-stage coarse stone used to set the edge. At the very least, you want to reduce the burr until it's very thin & small - do that with very light strokes at minimal pressure at the original sharpening angle. Then with the finer stone used to set the microbevel, you want to keep the number of strokes to an absolute minimum (1-3 per side), and the pressure very, very light, to avoid removing too much of the coarse-stage toothy bite from the edge.
 
Doing enough alternative strokes will take care of the problem imo. Do the same with each grit. You can debur and sharpen at the same time. 325 dmt edge done right can skin a tomato easily.
 
Deburr before moving to the next stone. If you still have a burr off your coarsest stone you havent finished on that stone yet.
 
It depends on the edge you're shooting for. I use anything from 80 - 400 grit for edge set-up and microbevel always with my finest stone or plate.
 
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