How Fine a Stone When Deburring a Coarse Edge?

[rummels]

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

[Marc H]

rummels,  long time…(I had been thinking this just last week).

I wouldn’t presume to know what’s the best way to achieve your goal.  Nor that how I do it is the best way.  Especially when I’m weighing in with another well experienced W.E. user.  This method I’ve worked into seems to do well for me.  It yields a good, very sharp working edge, that seems to be long lasting.  The burrs are removed with the completion of each and every grit stone I use.  Then the final edge leading strokes yield an exposed apex and a slightly toothy edge.

I use alternating sides, (left-right-left-right), edge leading strokes, (down and onto or into the edge) as my final sharpening stroke direction in this repetitious process or method I’ve come to use. I use the same bevel angle settings the entire sharpening process with each and every grit I use, start to finish.  This method coarsest grit to finest grit removes each burr formed right after its created, with each grit used, that made it.  Each successive burr from each finer stone gets smaller and thinner.  The final tiny burr from the last finest grit in my progression is removed with the final edge leading alternating strokes.  This is easily confirmed with visual inspection.  I use a USB Microscope.

I follow this last finest grit I am choosing to use on any knife with stropping. That’s irrespective of the stones or mediums I may be using.  For instance diamond stones, ceramics or whetstone, I do it the same.  I finish up with strops. I use a quick two grit stropping process, usually a 4µ, then 2µ emulsion on the basic W.E. (cow) leather strops.  I may follow-up with two even finer grit strops if a more polished edge is desired.

The final stropping seems to smooth the resulting toothy edge and lessens some of the grabiness that comes along with it while keeping the desired bite I’m wanting.  When starting a cut or slicing thru certain foods, tomatoes for instance, this can be very helpful.  Their smooth yet rubbery skin can embarrass even a very well sharpened knife that’s been finished maybe a little too refined.

I save using a slightly wider finishing bevel angle setting as a last step with the alternating side edge leading strokes, for when a tiny micro-bevel applied to the apex is desired or called for. The theory as I understand it is, the micro-bevel may improve the durability of the knife edge and add a bit of grab or toothines to it while possibly improving edge longevity.  It’s believed the Micro-bevel enhances how well the edge cuts while still allowing the benefits of the thinner underlying edge profile.

I usually don’t apply a micro-bevel till an edge touch-up seems needed.  It’ll refresh the sharpness quickly with very little effort.  I often do this with a few alternating side edge leading strokes on a  very fine grit hand held ceramic sharpening rod.

The subject you broached, “which finer grit stones are better for burr removal?”, is in the sharpening process you described in your original post.  Using the ceramic stones or the 3000 grit diamond is IMO a whole separate conversation.  Different mediums can be hard to quantify their actual or practical coarseness.  Comparably sized abrasive particles may behave from very similarly, to very differently while imparting very similar to very different  looking scratch patterns.  Even when high tech or metallurgical comparisons were conducted.  The bottom line for me are the results produced.  Just because the techy stuff suggest one way doesn’t mean that how it’ll be for you.  This is where I believe it becomes more about the user’s experiences, personal preferences. What I like to call “the art of knife sharpening”. Then decision-making based on technical data, specifications, or charts.

Marc
(MarcH's Rack-Its)

[000Robert]

I used to deburr a blade after sharpening with my 3000 stones using a couple of edge leading strokes. I stopped doing that and just use my leather strops to deburr blades now.

[tcmeyer]

I’m thinking that burrs that are persistent at the final grit probably indicate that the steel is rather soft and are probably related to the very low angle (15dps).  With very low angles (down in the 6-10dps range, some steels will produce a foil edge (so thin that you can bend the apex with your thumbnail).  Likewise, it can also produce a substantial foil-like burr, which will tend to flip from side to side.  Most of my knives produce very little in the way of burrs and those burrs that do appear are easily knocked off with one or two alternating leading-edge strokes at the same angle as the main bevels.  If I end each grit with a few alternating strokes, burrs don’t seem to be detectable except where I use an unusually high number of strokes.

[rummels]

Thanks to all for the very good advice and info!

rummels

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