Deburring Chisel VG-10

[Jason B.]

I just got my mind blown. I thought that shaving hair off my arm wouldn't happen below 600 grit somehow. I can't remember where I got this silly idea from.
Do I need to deburr aggressively first, or this is going to work even if some burr is left?

Do you have other tests after coarse stones to tell 'your apex is ready'? Catching on the nail?

P.S. So the burr I felt would've been from the previous sharpening? Or burr occurs even if not fully apexed? (I think I saw that in another thread - but my memory sucks - sorry for asking again)

Coarse stones produce more burr which is harder to remove but as with ANY STONE you use light pressure and you will reduce the burr size. With minimal burr on the edge from even a 100 grit stone you should still be able to pass simple tests.

If you create an apex it will typically be noticed by the full length burr created at the edge. It should show up and be "moved" from one side to the other as you switch sharpening sides. If this happens it a good indication you have reached an apex.

My "test" is always visual inspection, I look at the edge closely and under bright light looking for defect in the scratch pattern, burrs, and angle consistency.

 

[115Italian]

The only chisel grind knives ive sharpened are my Emersons. I think 10 degrees is to shallow. On the unsharpened side i only use a stropping motion to remove the burr. I use a fine diamond and ceramic sharpener to deburr the unsharpened side, not using a lot of pressure. I like more strokes than pressure.

 

[cbwx34]

So you push the burr with a stick and then grind in an edge-leading manner. Isn't that motion good at generating more burr? I observed a lot of videos with people doing edge-trailing strokes for deburring.

Bluntcut's technique is sound... give it a try.

Before doing that though, the first step I would take is, stop trying to sharpen this knife. You've already gone thru a couple of devices, several different angles, etc. You're going to reach, (or probably already have reached) the point where, even if you get an edge on it, it won't be sharp because of other issues going on (getting too thick behind the edge, multiple angles, etc.).

If you can, look at the bevels under magnification, and see if you can tell what you're actually doing. One thing to note... if it's convex as Jason said, it takes a lot of work to convert that to a flat grind... especially with something like the Lansky. And even more so if you were lowering the angle. That last "little bit" of getting to the very edge can take a loooooong time. So, even though at some point you may have gotten a burr (which may have actually been created when you worked the back side), it probably isn't truly apexed. If you've gotten to the point where you think you've put in a ridiculous amount of time reprofiling... that probably still isn't long enough.

Also, if this isn't a "practice blade"... one you might be willing to sacrifice 'till you get it right, you might want to set it aside, until you have a better understanding of the knife and how it was profiled/sharpened to begin with... and/or find someone (or learn) to reset the bevels if needed at this point.

 

[bucketstove]

I just got my mind blown. I thought that shaving hair off my arm wouldn't happen below 600 grit somehow. I can't remember where I got this silly idea from.
Do I need to deburr aggressively first, or this is going to work even if some burr is left?

Do you have other tests after coarse stones to tell 'your apex is ready'? Catching on the nail?

P.S. So the burr I felt would've been from the previous sharpening? Or burr occurs even if not fully apexed? (I think I saw that in another thread - but my memory sucks - sorry for asking again)

Hi,
yes, burr is sharp, it will shave but if its still curled over it will also scratch you
If you do a few alternating edge leading passes on the stone ("hard" stone)
or a few alternating edge trailing passes on a steel/rod or a strop
that should stand the burr up
you can shave/cut with that but it will fold back quickly

easiest way I found to get rid of burr, is after you stand it up using edge leading alternating passes on the stone,
increase the angle (+5 or double)
do 1-2 ultralight alternating edge leading passes
that should cut the burr right off

edge trailing is easier to make burr because you're pushing metal towards the edge

You can see actual arm hair shaving here Knife sharpening : 36 grit dressing stone - Cliff Stamp
36 grit is huge, its 538 microns or half a millimeter

 

[malaverdiere]

Thanks for everybody who pitched in!!!

I took all that advice, learned a whole lot, and this is what I did.

Sharpening object: cheap stainless steel santoku - messed up geometry from previous sharpenings and reprofiling
Sharpening system: Lansky. Rods set up in 20 degrees slot. Actual angle measured is 19 degrees (and I took time to level properly this time)

Method:
1 - Using the coarsest stone (black - 80 grit), I created a new apex. I used a 8x magnifying glass to tell that the scratch pattern went all the way to the edge
2 - Deburring using the same stone and driving through wood
3 - Testing the edge by cutting newspaper. I made sure to start the cut at different parts of the edge to make sure
4 - Repeat at step 1 until the test works
5 - Test to shave some hair - this is taking way too many passes, so go to step 1
6 - Switch to the coarse (red - 120 grit) and keep grinding and deburring
7 - Switch to the medium (green - 280 grit) and keep grinding and deburring
8 - Strop on leader loaded with green compound for additional deburring

Since it was getting late, I left it at that, and the edge doesn't look pretty. It is shaving hair, but it is not 'shaving-sharp'. And it can cut through curved newspaper without a problem.

And yes, the reprofiling at the coarsest stone reaaaaaaaaaaaaaally takes forever. Was getting fed up. I didn't expect it would take THAT long.

 

[Jason B.]

Reprofiling on a guided system takes much longer because with every pass you have a flatter and larger surface area you are contacting. Makes the last little bit take forever because you are contacting so much more of the bevel than when you started. Still, it's the most important part of the sharpening... everything beyond that is simply for refining the previous scratch pattern.