Burr is kicking my butt

R

realitycheck

Joined
Nov 24, 2007
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Hey guys im sharpening my dads buck odyssey 420hc steel. I got it down to 15 degrees primary bevel with my new dmt course dia-sharp benchstone. Before I moved to the sharpmaker I had a bad burr so I ran the knife across the stone at a slightly higher angle about two or three strokes on each side. The burr was still there but smaller. So I moved to the 15 degree slots on the sharpmaker I do 20 strokes on one side 19 on the other, 18 on the first side, 17 on the second, and so on. So I went through the routine on the medium stones. Still the burr was there, so I ran the knife across the medium stones at a larger angle about four times. It helped but still there. So I was thinking of going through my routine on the white stones also to see if it would remove the burr further but I dont know if it will or not. What is the pro's advice??
Thanks for the help guys.
 
I'd go to the white stones and go all the way through the motions. The burr shouldn;t interfere with the sharpening process. If it doesn;t whittle itself down to almost nothing by the time you finish, I'd strop it hard to medium-hard on a strop loaded with chromium oxide. Strop it 'til the burr's gone, then go back to the white stones, then back to the strop with very light passes.

I've never had a burr that large and persistent, I'm just saying what I'd likely do if I did.
 
For clean removal of the burr, I suggest micro-bevels +5 degrees per bevel. For some steels (ATS-34 for example), +5 degrees per bevel is a minimum. For any less, you may find you're just honing sharper burrs that flop from side-to-side during honing and immediately roll or chip away under any real cutting pressure.

For my own blades (S30V, VG-10, BG42, ATS-34), I use a micro-bevel of +5 degrees per bevel, Typically:
- Main bevels @ 10 degrees per bevel.
- Micro-bevel @ 15 degrees per bevel.

Hope this helps!
 
You got the original burr at 15°. You then " so I ran the knife across the stone at a slightly higher angle about two or three strokes on each side".
Because these few strokes were at a higher angle, when you went back to the 15° setting, you were now hitting above the edge. Always be careful when raising the angle.
Try a leather strop strop to assist burr removal after a few swipes at the higher angle you used....don't go back to the lower angle with hones.
Hope I have explained this correctly.
 
realitycheck said:
Hey guys im sharpening my dads buck odyssey 420hc steel. I got it down to 15 degrees primary bevel with my new dmt course dia-sharp benchstone. Before I moved to the sharpmaker I had a bad burr so I ran the knife across the stone at a slightly higher angle about two or three strokes on each side. The burr was still there but smaller. So I moved to the 15 degree slots on the sharpmaker I do 20 strokes on one side 19 on the other, 18 on the first side, 17 on the second, and so on. So I went through the routine on the medium stones. Still the burr was there, so I ran the knife across the medium stones at a larger angle about four times. It helped but still there. So I was thinking of going through my routine on the white stones also to see if it would remove the burr further but I dont know if it will or not. What is the pro's advice??
Thanks for the help guys.
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I do not know about this highering angle trick... To me - you get rid of burr but dull the knife. I got my results without it.

I look at the burr only as an indication that stone start affecting the edge and if I have burr for all length, I change side and when I have burr all length on other side I change stone - I do not get rid of burr, at all. On the next stone it usually get smaller and smaller. My sequence D8XX-D11C-D11E and then with burr from previous stage (Extra Fine DMT) I start polishing blade on leather with Green Rouge. Burr will disappear at some point, but I do not raize angle or do anything special to remove it, I just polish edge under same angle and it will disappear.

Thanks, Vassili.
 
How much pressure are you putting on the blade when you're removing the burr?

When I sharpen I also raise the angle to remove burrs (mainly because I don't have any super high grits or a strop). For me it never takes more than 3 passes on each side to remove the burr. I just use the weight of the knife and listen carefully. When you remove a burr you'll hear a louder scraping sound because its cutting off metal. One pass then feel for the burr and if its still there another pass and so on. If you happen to flop the burr over then repeat the same but as long as you barely use any pressure you won't have to go back and forth.
 
Well, this burr problem is the main reason why I don't like Bucks 420HC. In my limited experience with two Bucks in 420HC the steel feels like rubber to me. Very difficult to remove the burr. You just push it back and forth from one side to the other. The only way in my experience to get a decent edge is to avoid a burr as far as possible. Run the edge 90 deg into a medium hone to get rid of what you have now and rebuild the edge at what ever angle you choose, carefully with alternating strokes and frequent checking of the edge. Very tedious indeed.

Well stropping always implies some raising of the edge. Even with light pressure you will indent the strop some which will effectively increase the angle even if you hold the knife at the same angle. Only with stropping on a very hard surface like glass or steel this is not happening. Even on a soft waterstone, there is indenting and even more importantly the swarf will wrap around the edge, in a very gentle kind of way though.
 
Well I dont have a strop, so thats out. I keep thinking I need to get one but I just havent decided yet. Hob I see what your saying thats exactly what its doing, just back and forth, back and forth. I read one thing last night about a guy that would take the knife and run it perpendicular across a piece of wood or a broom handle or something. Then get back to sharpening. Do you guys think this would pull the burr off??
 
If you've flopped the burr over too much I believe that you won't get a strong edge so its probably best to cut off the edge and form a burr from scratch. Maybe thats what the wood is doing? I normally just run the edge in the groove of a sharpmaker rod a few times to kill the edge.
 
ziptrick after moving it through the groove of the sharpmaker would I then be able to go back to the medium stones again and start sharpening? I think I'll immediately go to the 20 degree slots.
 
realitycheck said:
Well I dont have a strop, so thats out.
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Well, have a fun with your burr then. IMHO - you need finer abrasive and leading motion. Ceramic only just will not work - too hard and does not absorb pressure variation during sharpening, good results will be always pure luck.

Fine water-stone may help also. IMHO -cheap thin leather belt, stretched over piece of wood + Green Rouge, best solution - should not be to hard and expensive to try. I think MDF may also work.

Thanks, Vassili.
 
Well it worked this time. I tried running the blade across some red oak, that didn't work. So I tried the groove on the sharpmaker stone that didn't work. So I moved up to the medium stones at the 20 degree angle like stretchnm suggested. Boom burr is gone. Went all the way through to the whites and instead of following my routine on the 20 degree angle I alternated sides of the blade on each stroke. Its hair popping sharp on both sides now and I cant feel the burr anymore. so im happy, hopefully my dad will be. Thanks for all you help guys. Hey noz wheres a good place to get leather for a strop? I probably just need to order some online I need to order the chromium oxide anyway?
 
Usually I am buying sharpening stuff in our local Woodcraft store. Here they are online:

http://www.woodcraft.com/depts.aspx?DeptID=2057

My leather I got from Tandy, it was like holster leather, I can not really say that someone selling it somewhere. But idea is that it should be thin enough to stretch a little and move a bit under blade, so it absorb overpressure when it stretched over flat piece of wood.

Here it is:

http://www.youtube.com/watch?v=3WY8rhecws8

Now looking at thick layer of Green rouge over it I start thinking that type of surface not really too important - in my case it all covered with thick layer of green rouge - it is like mirror waxed.

Thanks, Vassili.
 
You don't need anything fancy in terms of leather for a strop. Anything will do, as long as it will hold the compound. The harder the surface, the closer to the original sharpening angle you can hold the blade. Be careful when stropping on soft leather as too steep an angle and/or too much pressure will cause the leather to round the edge.

At the present time I'm using a piece of MDF with polishing compound.

Greg
 
I already got ultra fine stones for the sharpmaker. Will a strop really bring out the sharpness even more than these stones?
 
To remove a burr and reduce its formation in the first place do NOT hone one side at a time. Always hone edge-first and work alternating sides on each stroke left-right-left-right... Secondly remove the burr with the same hone you used to create it. Super-elevate the hone by at least 5 degrees when you debur. If you only do a few light edge-first strokes (always alternating sides) you will not dull the edge. The edge will actually flex away from the hone slightly and your burr-removing microbevel will not actually end up a full 5 degrees higher. After you deburr do a few more strokes lightly with the same hone at your normal honing angle. That will not create a new burr and will remove all trace of an elevated angle microbevel.

So on a sharpmaker I do all my honing work on the medium rods at 15 degrees (the "30-degree" slots) (alternating left and right sides). Do NOT use high pressure on your strokes, particularly when you use the edges. When the edge is sharp move the medium rods to the "40 degree" slots (rotated to the flats) and do about 4 sets of light left-right strokes to deburr. Move the rods back to the "30-degree" slots and do about 10 sets of light left-right strokes to restore full edge sharpness without creating a new burr.

Switch to the white rods and do the same using only the flats of the white rods. Use light pressure at all times when you are using the white rods.
 
realitycheck said:
I already got ultra fine stones for the sharpmaker. Will a strop really bring out the sharpness even more than these stones?
Click to expand...

My tests with measurements of sharpness did not show any improvement from Fine to Ultra Fine. I think it is matter of hardness - I think it is too hard to create very edge, may be it bend it instead sharpening creating burr not fine edge. Leather is soft and will not bend edge (as well as water stones), but it may round the edge if it is too soft and too much pressure applied.

Deburring with raising angle - again, is it really thin out burr so it fall out or just breaking it out because you bend it more? Did anybody test result other than shaving hand? I can shave after Coarse diamond, so to me this is not an indication of fine edge. If you shave hair itself - this is really fine edge. If you can do this after deburring - then I will believe it.

So I prefer to get rid of burr without changing angle I intend to have on my edge.

Thanks, Vassili.
 
After 800 grit, I use very light pressure on all stones, spyderco fine, UF, King 1200, 4K, 8K.

I don't strop the edges that have a burr, takes too long to remove at 60,000 grit.
 
I start wondering - what if ceramic just need some soft base to put under? Something what may absorb pressure variation? I remember you sad you did you sharpening holding you strop in you hand in air. May be this may sharpening on ceramic less damaging to ultra-fine edge? Some water bad or something like this?

Thanks, Vassili.
 
maybe, my ceramics are Spyderco Profiles, hold those in my hand as well. I also put a foot square ceramic tile on my lap to place the waterstones + holder. I have to use a light touch so the stones don't shift excessively. I like to feel both the blade and the sharpener when honing.
 
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