Please help me with burr/wire edge removal

S

sharpandsafe

Joined
Feb 25, 2011
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I am getting better at detecting a burr/wire edge, but now I think I am having trouble at removing it.

I chased a burr back and forth on a knife I sharpened to 1000 grit on the Edge Pro. It's a 154 CM blade sharpened to 30-deg inclusive. I tried removal in cork - no luck. Then I steepened the sharpening angle to 20-deg (from 15-deg) and used a couple very light edge-trailing strokes (stropping motion) with the 1000 grit stone. I am not sure I can still feel the burr. I may have scrubbed it off, but the blade doesn't seem to cut *quite* as well as before I steepened the angle. Also, I can no longer detect the burr under 60x magnification, but in fact, BOTH sides of the bevel seem to have that shiny burr-edge - probably I am looking at a tiny micro-bevel added by steepening the stone angle, but I can't tell if either side has a burr/wire edge anymore due to the micro-bevel (if that's what it is).

How do you recommend I proceed? How do you remove a burr/wire edge without steepening the angle of the bevel too much?

Thanks - your help is greatly appreciated!
 
sharpandsafe said:
(...) Then I steepened the sharpening angle to 20-deg (from 15-deg) and used a couple very light edge-trailing strokes (stropping motion) (...)
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I'd use edge-leading strokes, i.e. into the edge at the elevated angle, instead of edge-trailing. With ductile steels, it's most often easier to let the burr fold back to one side of the edge, and then 'cut it off' by using edge-leading at a slightly greater angle. An edge-trailing stroke at elevated angle probably will just fold the burr further away from the apex, toward the side opposite the hone. If so, THAT'S the time to switch to edge-leading on the side the burr is leaning to, and cut or scrub it off at very light pressure, so as not to create a new burr.

I don't have an EP, but this same technique applies to sharpening in general.


David
 
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I feel for you sharpandsafe! Complete burr removal without tons of stropping on different mediums and compounds can be a challenge. I'd suggest, before you remove the burr, to scrape the edge sideways on a wooden stick to the opposit side where the burr is as if you would want to comb the burr over all to one side. That way you make sure none of the burr is going straight up the apex etc. Then you take the side where the burr is and remove it with edge leading strokes only, no forth and back, no edge trailing. Try to actually avoid to create a steeper microbevel at this point, you can apply it after! This should be particularly easy with the EdgePro!! Burr removal may take some time when "filed" off like this but you end up with a better edge. Once the apex is clean, apply the microbevel with a fine stone with very little pressure since you can easily produce a new burr!
 
Thank you David and Andy, for your suggestions!

David, I used your advice last night, and I think I am seeing an improvement in the cutting ability of the edge. I also got out and used my Edge Pro glass blank and polishing strips for the first time. I was pleasantly surprised by how durable these tapes feel! I think I may still have a tiny bit of burr left that I can't seem to get rid of. Should I perhaps look at putting my strop together? I am push cutting newsprint across the grain easily, near the point of hold, with a very slow cut. There does seem to be a bit of roughness, though, but the knife didn't "catch" in the newsprint.

Andy, I am not sure I understand your suggestion. Do you mean that the edge should be held at a high angle to a piece of wood, like this "/" if the slash is the knife blade in cross-section and the bottom of the line of text is the wood? And, should it then be dragged across the wood in this "->" direction (spine leading)? Thanks! I guess what I envision is like an extreme-high angle stropping motion.
 
sharpandsafe said:
Thank you David and Andy, for your suggestions!

David, I used your advice last night, and I think I am seeing an improvement in the cutting ability of the edge. I also got out and used my Edge Pro glass blank and polishing strips for the first time. I was pleasantly surprised by how durable these tapes feel! I think I may still have a tiny bit of burr left that I can't seem to get rid of. Should I perhaps look at putting my strop together? I am push cutting newsprint across the grain easily, near the point of hold, with a very slow cut. There does seem to be a bit of roughness, though, but the knife didn't "catch" in the newsprint. (...)
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With a guided sharpener, I've always tried to make the most of sticking with it until there's absolutely no doubt that I've cleaned up as much of the burr as possible. With some steels, burrs that may seem very small might still be difficult to clean up on a strop (VG-10 comes to mind, on Spyderco's blades; those burrs are amazingly tenacious at times). Sometimes the leather and compound just won't be quite aggressive enough. Using the finer hones at increasingly lighter pressure always works better, especially when the hones are guided. By the time the finishing touches are being done, the pressure used with the finest hone should be almost literally feather-light, and you shouldn't feel much, if any resistance or drag against the bevels (a relatively stiff burr, leaning to one side or the other, will often be felt this way). At that point, assuming the edge is fully apexed, whatever burr is left should be so thin that almost any stropping action should remove it.

Based on what you're describing of your cutting tests, it sounds like you're very close. If you want to give your strops a try, go for it. But you might still benefit from doing as much fine-tuning with the hones as you can, so the stropping afterwards will seem like a breeze. And it should also produce a noticeable improvement in cutting with just a handful of passes on the strop, if the edge is truly 'ready' for it.


David
 
sharpandsafe said:
Andy, I am not sure I understand your suggestion. Do you mean that the edge should be held at a high angle to a piece of wood, like this "/" if the slash is the knife blade in cross-section and the bottom of the line of text is the wood? And, should it then be dragged across the wood in this "->" direction (spine leading)? Thanks! I guess what I envision is like an extreme-high angle stropping motion.
Click to expand...

You got it sharpandsafe. Just like stropping at a very obtuse angle. In my experience at the stage of burr removal, it does no harm to the actual apex but combs all the burr to one side. Here is the link to an excellent thread about combing burrs and removal of same. Worthwhile to check it out!:

http://www.bladeforums.com/forums/s...l-Geometry-cross-sectional?highlight=bluntcut
 
David,

I have taken your advice, and I will make sure to get the cleanest, fully apexed edge I can get before heading to the strop with 0.5 um chrome oxide.

Andy,

Thank you for the clarification, and for the link to that other thread. I have some basswood I think would work well for this method. I will try it on my next sharpening job to see if it makes implementing David's method easier.
 
One more thing sharpandsafe I like to add. HeavyHanded and me have been rambling about this a bit. Once you think you have your edge where you want to have it, let us say cross cut newsprint cleanly or so, you can do the same method to proof your edge being 1) clean of any burr, and 2) strong enough for more than cutting newsprint! You will be surprised how easy you bring up a "new" burr that was "not there" before or how easy you "bend" a fine burr free apex. However this time of course you would do it again at a very obtuse angle 70-80 deg in fact, but with lighter pressure, you don't want to ruin your edge.
 
Got it, Andy. If I take my perfect edge to the wood (lightly) in the manner you describe and it ruins my seemingly perfect cutting edge, then the edge really needed more work (I was probably dealing with weakened steel at the edge or a straightened burr in my cutting tests) and I should keep at it until I get a more durable, but still razor-sharp edge.

I am thinking that 30-deg inclusive may be a bit too thin for this knife (small hunter) in this steel (old school 154 CM). I am thinking of steepening the cutting edge a little bit. What do you think?
 
I decided to make a video on just burr and wire-edge removal. 2nd attempt, it's 16 minutes long, hopefully the key fold&cut technique successfully conveyed.

[video=youtube_share;l2ynSDYEUYI]http://youtu.be/l2ynSDYEUYI [/video]
 
I like to remove a burr on the Spyderco Sharpmaker using the fine or extra fine stones. The fact that you're changing sides on every stroke gives that burr no place to hide. Moving the burr from one side to the other on every stroke mean it is either ground off or falls off.
 
If I have a burr that's not behaving by not going away, I strop
on denim cloth. Usually while I'm wearing the jeans. I strop on the
thigh area lightly. You can really feel how much pressure you're using
and can easily feel when the burr has left. Scares the heck out of my customers
but it's a very successful method of burr removal.
 
I've been playing around lately with using a couple different compounds on thin cardboard, over glass, for stropping my edges. The compounds I've been using the most are some 3-5µ 'white' Ryobi compound I picked up at HD, and also some Simichrome polishing paste (~ 9µ, per the mfr.). The cardboard I use is the simplest and most easily available, just some kleenex/crackerbox-type stuff, using the inside (unfinished) face. I used a little spray adhesive to lightly tack the cardboard to the glass. The adhesive is a type that allows temporary bonding; spray the cardboard and wait a few minutes for it to become tacky; then just press it to the glass. It can easily be removed & replaced when it gets worn out or too dirty.

I bring this up because I've been noticing this method works GREAT for stropping some pretty tenacious burrs & wire edges away from steels like 420HC and VG-10, and anything else I've tried (1095, Case CV, Queen D2, 440C, 440A, ZDP-189 and S30V). 420HC and VG-10 were previously at the top of my 'most PITA burr-makers' list (;)), so I'm doubly impressed at how well the method seems to work with those. Additionally, the thin cardboard-over-glass minimizes any curling/rolling of the stropping surface around the apex, which obviously makes for more refined edges. Even under more pressure and at a faster pace, they're coming off wicked-sharp this way, and I may abandon leather-stropping altogether after seeing how well this method works.


David
 
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Bill Hoffman said:
If I have a burr that's not behaving by not going away, I strop
on denim cloth. Usually while I'm wearing the jeans. I strop on the
thigh area lightly. You can really feel how much pressure you're using
and can easily feel when the burr has left. Scares the heck out of my customers
but it's a very successful method of burr removal.
Click to expand...

IDK about this for burr removal. I can't believe that cotton (denim) actually REMOVES a burr - more likely just straightens it out. I do like a similar method for detecting a burr, though, as cotton fuzz will cling to the burr when lightly stropped against the thigh.
 
Obsessed with Edges said:
and also some Simichrome polishing paste (~ 9µ, per the mfr.).
Click to expand...

I was wondering about this. Is this 9 microns for the pink stuff in the tube? That's what I have.

Obsessed with Edges said:
The cardboard I use is the simplest and most easily available, just some kleenex/crackerbox-type stuff, using the inside (unfinished) face. I used a little spray adhesive to lightly tack the cardboard to the glass. The adhesive is a type that allows temporary bonding; spray the cardboard and wait a few minutes for it to become tacky; then just press it to the glass. It can easily be removed & replaced when it gets worn out or too dirty.
Click to expand...

What is this mystery adhesive you use? Something similar to what's on the back of Post-It notes would be great!
 
sharpandsafe said:
I was wondering about this. Is this 9 microns for the pink stuff in the tube? That's what I have.
Click to expand...
Yes, that's it. :thumbup:

What is this mystery adhesive you use? Something similar to what's on the back of Post-It notes would be great!
Click to expand...

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I picked this up at a Woodcraft store (actually got my Simichrome there as well).


David
 
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