Burr help..

Django606

Django606

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Jul 22, 2005
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I'm having trouble identifying and removing burrs. If it matters at all, the steel is 154CM. I find it very hard to tell which side the burr is on, and if I have ground it off completely. I'm using the Sharpmaker. To check for the burr, I was following the eGullet forums sharpening post, which said to hold the blade horizontally and brush your fingertips down the edge at a 45* angle. I find it very hard to check if the burr is actually there or not using this method.

Also, how would you reccomend I remove the burr? I have been tilting the knife slightly towards the center of the Sharpmaker to increase the angle when I try to remove the burr. I press very lightly, which doesn't seem to grind the burr off, and then I try a little harder, which just pushes the burr over to the other side. This, and the fact that I have trouble detecting the burr in the first place, make it very frustrating when I try to put the finishing touch on my knife.

My main questions are: What is the best/easiest way to check for a burr, and what is the best/easiest way to remove a burr?

Thanks in advance for any help.


Edited to add: I am concerned about this because I thought I had ground the burr off completely, and the knife push cuts news print very easily, but when I went to shave my arm, one side was much better than the other (one was hair popping, one was barely shaving.) I know some people have said that this occurs because of a burr, but I was almost positive I had ground the burr off. Also note that I have not sharpened the knife all that much, I just sharpened it enough on the flats of the fine stones on the Sharpmaker to achieve a burr.
 
I've had similar chase-the-burr problems with ATS34, which is similar to your 154CM blade steel.

Try knocking the burr down by hard-pressure slices into hardwood (broomstick, shovel handle, etc.). The edge will be a mess with the rolled burr and perhaps some gaps due to torn-away burr, but it should clean up pretty quickly with a microbevel of about +5 degrees on each bevel. If not, just increase the micro-bevel angle a bit.

In my incident, the floppy burr formed with a narrow main bevel of about 20 degrees included, requiring a micro-bevel of 30 degrees included to remove the burr and stabilize the edge (Buck/Strider Tarani ATS34 blade).

Hope this helps!
 
Django606 said:
IMy main questions are: What is the best/easiest way to check for a burr ...
Click to expand...

If you sharpen by switching sides then when a burr forms it will do so unevenly and parts of the edge will have a burr on one side and parts will have it on the other and parts won't form it at all. The easiest way is to just one one side until a burr forms. With a little practice you can see it by eye and it is trivial to see under even low magnification. A small magnifier will help out a lot because it will tell you if you are in fact honing the very edge or the metal above it.

...what is the best/easiest way to remove a burr?
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Elevate the angle significantly, make a few very short and very light passes on a very clean and very large stone with a high cutting aggression. If this fails to be productive then the edge is likely highly worn or otherwise weakened and you are often help by just grinding it right into a stone and cutting the edge off and reforming it from the beginning. Just 1-2 light passes is enough.

...the knife push cuts news print very easily, but when I went to shave my arm, one side was much better than the other (one was hair popping, one was barely shaving.)
Click to expand...

There are several types of burrs, that is a deformation burr, the edge is just bent to one side and it will keep moving from one side to the other as you hone. It happens frequently on ceramic rods as the contact pressure is really high and so the steel is pushed out of the way rather than be cut by the abrasive. If you have attempted to remove the burr without success you have likely weakened the steel significantly by flopping it back and forth and it will be impossible to form clean as the metal is highly fatigued so grind it off and start over.

-Cliff
 
Thanks for the replies.

So you're saying I should start over, maybe just on the flats of the white stones, but instead of alternating sides every time, do one side for five minutes and then the other side for five minutes?

When I go to remove the burr, tilting the knife inwards towards the center of the two rods is increasing the angle, right? I think another thing I have to do is clean the stones.
 
The white rods should be the final stage, you should not be honing on them for minutes. Take the knife and cut light right into the fish hook groove on the medium stone, just 1-2 light passes. This will cut off all the weakened metal and give you fresh steel to work with. Using the flats of the medium rods, bring the edge to an even burr. Then switch to the other side until the burr forms completely on the opposite side. Elevate the angle and cut off the burr with a few light passes, yes this means to rotate the knife away from the stones. You now proceed to the white stones. Since the burr has been removed you now alternate passes until the edge is refined. You may need to give it a final few passes on an elevated angle to minimize any burr which forms from the white stones. Avoid the corners completely if you are having burr problems and make sure the stones are very clean. You also need to realize that those types of steels in general can be very frustrating to sharpen because they are very wear resistant, coarse grained and relatively weak. You will also make life a lot easier on yourself if you get a x-coarse benchstone and apply a relief grind to the edge so the Sharpmaker is only micro-beveling.

-Cliff
 
After removing the weakened metal, do I use only the flats of the medium and then fine stone?
 
Yes, generally you use the corners for aggressive honing, but if you are having problems with removing burrs then you avoid them.

-Cliff
 
When I sharpen on the grey flats until I get a burr on one side, do I just sharpen the other side enough to get a burr, or should I grind for the same amount of time as I did the first side?

Thanks for all your help Cliff. As for checking for the burr, what would you recommend? Do you just check with your finger/thumbpads?
 
Just sharpen until the burr forms evenly on the other side. You can feel it with some practice as well as see it by eye and trivially under even light magnification. A quick check on the arm will tell because it will shave on one side readily right off the medium stones.

-Cliff
 
The sharpening article on eGullet Forums is great, but the method he uses for detecting a burr doesn’t work very well for me either. Instead, try slowly running a fingernail down the blade (laterally) and over the edge. If there’s a burr there, it will catch on your nail.
 
Thanks, I'll try that. I'm not really sure exactly what you mean, do you mean run your fingernail so that if there is a burr, it would catch underneath your fingernail?
 
Yeah… If you run your fingernail over the edge and a burr is present on that side, your fingernail will catch on the burr.

I’ll see if I can post a pic to help illustrate it a little bit later. File uploading seems to be down at the moment. :(
 
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