Sharpening (Burr Specifically)

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Cait_Sith

Joined
Oct 5, 2010
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Hey guys I've been freehand sharpening recently and I've always wondered how to exactly treat the burr on the edge between various grits.

Normally I start out on a course stone to establish a proper bevel. So I begin with one side (let's call it side A), and once I form a burr, I switch over to side B and form a burr there.

Should I stop and move onto the next stone to remove that burr? Or would it be better to finish the edge properly with the course grit before moving on to a finer one?

Any input is much appreciated.
 
Once you've formed and 'flipped' the burr with the first hone, you can (but don't have to) use that hone to begin cleaning the burr up. Use much lighter pressure than for the previous 'grinding'; basically, you're just trying to file down that very thin & delicate sliver of steel, without degrading the new edge immediately behind it. If the coarse hone feels a bit too aggressive for this 'light' work, use the subsequent hones in a similar manner, to gently and gradually file the burr away and/or break it off. With more experience, you'll no doubt develop a 'touch' for cleaning up the burr early, so the subsequent work with the finer hones will get much simpler.
 
strop it off with a peice of leather or use a peice of soft scrap wood and run the blade down it to knock it off.
 
if you decide to use the current stone to remove the burr be careful not to slightly increase the angle to achieve it,
if you do you'll create a microbevel that will mean more grinding on the subsequent stones to remove, if you want a microbevel then create it on the last stone that you use.
 
Cait_Sith said:
Hey guys I've been freehand sharpening recently and I've always wondered how to exactly treat the burr on the edge between various grits.

Normally I start out on a course stone to establish a proper bevel. So I begin with one side (let's call it side A), and once I form a burr, I switch over to side B and form a burr there.

Should I stop and move onto the next stone to remove that burr? Or would it be better to finish the edge properly with the course grit before moving on to a finer one?

Any input is much appreciated.
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I do not move on to a finer grit unless the burr is quite small. If I'm repairing a blade or cleaning up the factory bevels I will reduce the burr as much as possible - leaving it till later can cause issues with wire edges or stubborn burrs that won't come off without going back to a coarser grit or rounding your edge on a strop.

Doesn't hurt to remove it entirely from time to time - it'll give you a chance to perform some cut tests at various grits levels and it will help your ability to remove stubborn ones at finer levels.

One trick I use is to keep a short 8" or so length of 1/2" hardwood dowel on hand (the edge of a wood work-bench or cutting board works well too). When you've raised a burr on both sides, lightly backdrag the edge along the dowel at a steep angle, nearly perpendicular to the blade. This encourages the burr to lean even further over the opposite edge (it isn't enough to flip the burr by itself, so use it to help the direction the burr is already going). Using a light touch I find it a lot easier to grind the burr down without having to increase my bevel angle or use a microbevel. Next, I repeat on the other side, reducing pressure with the dowel every pass. Even the most stubborn of burrs can be tamed in short order, I usually have to repeat this no more than twice/side. I've finished off 220 grit edges in this manner, stropped on plain newspaper and you have a very nasty coarse edge virtually burr-free without using a loaded strop. Or you can advance up to the finer grit values with an absolute minimum of burr to deal with, something I find is actually quite helpful.

For me this is quite a bit faster than flipping the burr using just the pressure of the stone, though this works every bit as well.
 
The advice so far is very good. I normally try to remove as much burr as possible on whatever stone I'm using before I move to the next grit. Lately I have been trying to modify my sharpening so that I don't create a noticeable burr at all. Basically I want to sneak up on the apex from both sides, and switch to alternating edge-leading strokes just before the burr would form. That should be more efficient in terms of time spent and steel removed, but it's tricky to know when the burr is going to form. Also, it is pretty much impossible to do it this way when you have damage to remove from the edge, since you will pull up a burr on the good parts before removing all of the knicks. If I am trying to polish the edge really well, I can pull up a burr before I'm satisfied that all the courser scratches are gone. But overall I think this works more efficiently than my previous method of sharpening on one side only until a burr is felt, then repeating on the other side.

I like the "scraping the edge on wood" technique Heavy Handed mentioned for dealing with a burr. I have always seen people pull the knife edge straight through wood to "deburr" but it never seemed to remove the burrs for me. Scraping the edge along some wood to bend it over seems like it would make it easier to cut off.
 
Regarding using wood to de-burr an edge, there's a HUGE variability in how effective it works. I like the technique, but often need to 'improvise' a little bit, depending upon the size and stubbornness of the burr itself. That, in it's own right, varies widely from one steel type to another. The most tenacious burrs & wires I've seen are with VG-10 and ATS-34. Both of these steels are known to stay more ductile at higher hardness, where many others would become more brittle (and therefore easier to break burrs off). The ductility is what really makes burrs hold on. 420HC is also like this, though it's generally not quite as stubborn as the other two. If they won't break off, they're still relatively easy to abrade away. All the more reason to really watch for the early signs of burr formation, so you can catch it while it's still fairly small.

I've used the corners of my oak strop block to draw the edge through, and I've also lately been using a piece of 1/2" hardwood dowel. Curious thing about the dowel, it's got a lot of crosscut marks in it, after all the draw-cutting strokes with the blade. On a whim, after making a few draw cuts with a blade one day, and still feeling some burr along the edge, I 'stropped' the edge along the dowel, 'clattering' across all those cut marks along it's length (sounded terrible). To my pleasant surprise, this did a great job in knocking the wire off that edge. Didn't seem to faze or hurt the 'good' edge left behind either.
 
Obsessed with Edges said:
I've used the corners of my oak strop block to draw the edge through, and I've also lately been using a piece of 1/2" hardwood dowel. Curious thing about the dowel, it's got a lot of crosscut marks in it, after all the draw-cutting strokes with the blade. On a whim, after making a few draw cuts with a blade one day, and still feeling some burr along the edge, I 'stropped' the edge along the dowel, 'clattering' across all those cut marks along it's length (sounded terrible). To my pleasant surprise, this did a great job in knocking the wire off that edge. Didn't seem to faze or hurt the 'good' edge left behind either.
Click to expand...

That's exactly how I came to my method - I was using a dowel to draw the edge across, but it seemed to me that the burr had to be so small and weak for this to work, I was spending lots of time flipping the burr just to weaken it. As you say, on some steels one might need to break for a snack. The more flips one has to make with relatively few passes, the harder it is to hold really consistent angles (for me anyway), so on an impulse I decided to try flipping it with the dowel. That didn't work so well but it did make it stand more "proud" on the opposite side, making it easier to grind off with the lightest possible pressure. What's left I can remove with plain newspaper (or by drawing it across the wood, though I still find this unreliable).

I still draw the edge across my dowel from time to time at the lower grits, but that's more to maintain my notches than because it removes the burr well for me.:)
 
HeavyHanded said:
That's exactly how I came to my method - I was using a dowel to draw the edge across, but it seemed to me that the burr had to be so small and weak for this to work, I was spending lots of time flipping the burr just to weaken it. As you say, on some steels one might need to break for a snack. The more flips one has to make with relatively few passes, the harder it is to hold really consistent angles (for me anyway), so on an impulse I decided to try flipping it with the dowel. That didn't work so well but it did make it stand more "proud" on the opposite side, making it easier to grind off with the lightest possible pressure. What's left I can remove with plain newspaper (or by drawing it across the wood, though I still find this unreliable).

I still draw the edge across my dowel from time to time at the lower grits, but that's more to maintain my notches than because it removes the burr well for me.:)
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I remember thinking, when using the notched dowel for stropping a wire off, "this is very encouraging, but needs more 'research'..." ;). Don't remember which blade or steel it was, that first time, so I guess I'll have to play around with this some more, with 420HC (Case, Buck), ATS-34 and VG-10 blades. If I can make it work on those, I figure it's gotta be a winner. :)

I've also done something similar using the stainless steel barrel of a ballpoint pen, which had sort of a machine-turned satin finish, and fine lateral 'grooves' in the steel. This produced sort of a 'buzzing effect', when drawing the blade along it's length (edge-trailing). That also worked pretty well. Light pressure is more important here, against the steel.
 
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