Author Topic: Struggling to get the burr  (Read 1378 times)

Offline John Deignan

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Struggling to get the burr
« on: August 22, 2019, 08:37:39 pm »
A couple novice questions here, concerning the burr on knives.  I have been using a T-8 for some months now, mostly on kitchen knives.  Sometimes I can get a knife pretty sharp (cuts paper), but other times not so much. I generally shoot for 30 degrees (15 on each side).  Whether I make a single pass per side, or several passes on one side, then several passes on the other, I seem unable to detect the fabled burr.

I run my thumb or finger nail across the edge, anticipating a rough edge/catch, but I just don’t feel it.  I went out and bought several magnifying loupes, but honestly don’t see anything, either.

Last month, I went to a knife maker who demonstrated sharpening a knife on a type of belt device, and the burr on that knife was obvious. So I must be doing all sorts of things wrong. 

I think I have exhausted every video on Youtube and have poked around this forum as well, so any guidance on any of these questions is really appreciated.

Questions:
[1] Using the knife jig, do you press the blade firmly on the stone, or just lightly rest it against it?
[2] How many passes (back and forth) do you generally make until you feel a burr?
[3] Do you make several passes on one side, then flip the blade, or alternate every pass until a burr forms?
[4] I tend to keep the stone at the higher grit.  Should I be using the coarser grit?
[5] Is there such a thing as a general sense of how many passes (per side) it generally takes to sharpening kitchen knives? Five? Twenty five? I've honestly gone way past that sometimes in my frustration.  Feel like I'm flying blind....

Thanks for any info.

Offline RickKrung

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Re: Struggling to get the burr
« Reply #1 on: August 23, 2019, 06:27:18 am »
This is the only magnifier I use for examining bevels/apex/burrs, Kingmas "currency detecting microscope".

I use it to examine the entire length of the bevel on both sides on just about every knife.  The burr will often appear as a ragged black fringe, but if you are using a black marker, you have to be able to distinguish the two.  Another way to describe the burr is like a string of tiny scales extending from the apex. 

It takes some practice getting used to the hand microscope.  Getting the barrel positioned so you can see the bevel.  Getting it in the right position on my eye.  Moving along the bevel.  I position the barrel so it focuses a little closer than I need and then rock it back and forth to bring different parts of the bevel into focus.  Mark Reich is the member who put me on to it, I thought, but I just looked him up and he is listed as a newbie with no posts.  It did come from Mark, but on the BESS Exchange

I think you may want to set your stone (I assume the SG) more coarse.  I think you could use the truing tool to put on a fresh surface and NOT use the stone grader to keep it coarse until you get the burr.  More pressure might help. 

Which direction are you working?  Edge leading (off the vertical USB) or edge trailing (off the horizontal USB).  It has been said that the burr is more difficult to detect with edge leading.  Detecting the burr from edge leading can definitely be more difficult. 

Rick
Quality is like buying oats.  If you want nice clean, fresh oats, you must pay a fair price. However, if you can be satisfied with oats that have already been through the horse, that comes at a lower price.

Offline Jan

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Re: Struggling to get the burr
« Reply #2 on: August 23, 2019, 09:42:12 am »
Welcome to the forum, John!  :)

Burr formation strongly depends on the properties of the steel. Generally it is more difficult to rise the burr on a hard blade with hardness larger than some HRC 58. For training purposes use inexpensive kitchen knives made of milder steel, some HRC 53 – 55.

Jan

Offline Ken S

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Re: Struggling to get the burr
« Reply #3 on: August 23, 2019, 12:59:47 pm »
Another welcome to the forum, John.

My suggestion is to try making your wheel surface more coarse with the stone grader. You can feel the difference with your fingers. You are at a frustration point. Just making the wheel more coarse with the stone grader should help. Don't be afraid to put some pressure on the stone grader. Use it for the better part of a minute.

Do not get frustrated. This is like learning to drive a car with manual transmission. You will stall a few times. Soon you just drive.

Be patient and keep posting. We are all cheering for you and have all been where you are now.

Ken

Offline john.jcb

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Re: Struggling to get the burr
« Reply #4 on: August 23, 2019, 03:18:57 pm »
Welcome John,
To answer your other questions on burr formation you want to take several passes in the same direction to raise a burr. I find that several passes (3-4)with moderate pressure with a coarse setting on the stone is best if the knife is quite dull. When sharpening a knife that you have previously done there is really no need to use the coarsest setting. I find that if you do not use the grading stone the grinding stone will settle in about half way between coarse and fine. I use this on most knives then grade fine for finishing the edge. If you watch the videos by Jeff Farris https://www.youtube.com/watch?v=fYURcwkKGPs&t=466s you will see he is not exerting much pressure. You may also find that it takes more passes if you are altering the angle on a knife. More work must be done if you are changing the angle say from 20° per side to 15°. If you look under magnification it is apparent where you have sharpened and where you have not when changing the angle.

Also watch the part of the video where he hones the blade on the leather wheel. This is a critical step in removing the final small burr that remains after sharpening both sides on the stone. Doing this step without a jig as he shows is not difficult but it takes a little practice to get the feel for it.

Sharpening using the Tormek should be relaxing. If you are feeling any stress in your shoulders or arms you are using too much force. Let the wheel do the work. When you are done sharpening it should cut newsprint very easily. I use the advertising from the grocery I get in the mail or a store receipt. If your knife will easily cut these it is sharper than 90% of new knives out of the box.
Sharpen the knife blade
Hone edge until perfection
Cut with joy and ease

Offline John Deignan

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Re: Struggling to get the burr
« Reply #5 on: August 23, 2019, 03:38:13 pm »
Thanks so much for the great advice, guys!  Definitely will try the coarser grind, trailing edge, getting a proper visual scope, and staying on one side for multiple passes - all of which I had not been doing!  These are great insights, can't wait to try them!   

Offline Elden

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Re: Struggling to get the burr
« Reply #6 on: August 24, 2019, 05:24:42 am »
  Mark Reich is the member who put me on to it, I thought, but I just looked him up and he is listed as a newbie with no posts.  It did come from Mark,

Rick


Rick,
Try looking under "grepper".
Elden

Offline Ken S

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Re: Struggling to get the burr
« Reply #7 on: August 24, 2019, 11:06:11 am »
Mark Reich is a very experienced knife maker and sharpener. Any reference to him as a "newbie" refers only to his time on this particular forum, not his knowledge or skill.

Grepper is certainly no newbie, either. For some time he has been my "go to guy" for many forum related subjects.

We are quite fortunate to have these two as members.

Back to raising burrs: While you are learning, I suggest grinding on only one side of the knife until you can feel a burr along the entire length. I know the knife people will disagree, however, I still reach for my box of 3/4” Irwin Blue Chip chisels whenever I want to learn or test something. (Look at the first topic anchored at the top of the General Tormek tab. Sorry it became so long; I am closer to doing it as a you tube.) I once sharpened one of my sharpening chisels using an 80 grit CBN wheel. This produced the most amazing foil burr about an eighth of an inch (3mm) long!

Be patient and persistent, John. You will soon reach the finish line!

Ken

Offline Scott an Edge

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Re: Struggling to get the burr
« Reply #8 on: August 24, 2019, 03:55:44 pm »
G’Day John,
I concur with the other knowledgeable posts and your summary of their advice.
I would like to add a few points.
- while practicing, try using a lower sharpening angle to create a burr that is easier to detect (finer, weaker and bendier) until you get the hang of it I.e. about 12deg per side for a knife. If you grind at 90deg you would never raise a burr ;-)
- use the marker method to match the grinding angle to the blade bevel. This should result in a burr in the shortest time
- listen! I have found that my T-8 sounds different when: grinding the full face of the bevel compared to only part of it (changing original bevel angle). The greatest change in the sound is when I flip the knife over and run the first pass over the burr.
- I use a 10x lense and a very bright light to inspect my edge and burr. Catching the light at different angles can tell you a lot about your work.
- But, the most reliable inspection is by feel. Run you finger pad from the side of the knife, over the bevel then across the edge on both side - if they feel different it is likely you have a burr.
- I agree that using the T-8 is very therapeutic.

Best of luck.
Cheers
Scott

Offline alanhuth

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Re: Struggling to get the burr
« Reply #9 on: August 26, 2019, 04:31:36 am »
I think if you read Wootz’ book all your questions will be answered.

Offline John Deignan

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Re: Struggling to get the burr
« Reply #10 on: September 05, 2019, 07:22:14 pm »
Thank you, everyone for all your advice.  With a better quality of light and magnification, using the trailing edge with a coarser stone setting and focusing on one side of the blade, I can now very much feel the burr!  You advice has made a huge difference and my faith is very much restored in this system.  I still have much to read and learn first hand, but feel that I am much more on track, all thanks to your insights.  Looking forwards to building my knowledge via your reading suggestions and this forum!

Offline john.jcb

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Re: Struggling to get the burr
« Reply #11 on: September 05, 2019, 09:32:03 pm »
I also wanted to point out that the burr you see in print or on the Internet is greatly exaggerated so that you can easily visualize it. As you become more experienced you will be able to detect a much smaller burr along the blade. It is not necessary to have a relatively large burr for proper sharpening. After all you are just going to grind it off when you sharpen the other side. The final burr you will have after using the finest setting on the stone is almost undetectable. When you move to the honing step you are actually honing off the remaining burr leaving a polished and extremely sharp edge.

This is the subject of many threads here, final burr removal and honing. When you have properly honed the blade you will have an extremely sharp edge that will last you longer.

lastly, learn how to properly use a steel to maintain your edge. You can significantly extend the time between sharpening if you use the steel prior to each use of the knife.
« Last Edit: September 06, 2019, 04:59:43 pm by john.jcb »
Sharpen the knife blade
Hone edge until perfection
Cut with joy and ease

Offline Ken S

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Re: Struggling to get the burr
« Reply #12 on: September 06, 2019, 03:14:12 am »
John,

Jeff Farris' videos are excellent starting points. Jeff used to demonstrate with Forscher (Now Victorinox) chef's knives. They are good knives at a reasonable cost. I try to keep some "sharpening tools" on hand, good tools not overpriced. The Victorinox knives use good steel, not exotic and not junk.

Grind one side until you can feel a burr. Once you get this, grind the other side until you get a burr. Perfection will come eventually. Right now, you just want to successfully raise a burr.

Persist, have patience, and keep us posted.

Ken

Offline Erivan

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Re: Struggling to get the burr
« Reply #13 on: September 06, 2019, 08:55:56 pm »
A couple novice questions here, concerning the burr on knives.  I have been using a T-8 for some months now, mostly on kitchen knives.  Sometimes I can get a knife pretty sharp (cuts paper), but other times not so much. I generally shoot for 30 degrees (15 on each side).  Whether I make a single pass per side, or several passes on one side, then several passes on the other, I seem unable to detect the fabled burr.

I run my thumb or finger nail across the edge, anticipating a rough edge/catch, but I just don’t feel it.  I went out and bought several magnifying loupes, but honestly don’t see anything, either.

Last month, I went to a knife maker who demonstrated sharpening a knife on a type of belt device, and the burr on that knife was obvious. So I must be doing all sorts of things wrong. 

I think I have exhausted every video on Youtube and have poked around this forum as well, so any guidance on any of these questions is really appreciated.

Questions:
[1] Using the knife jig, do you press the blade firmly on the stone, or just lightly rest it against it?
[2] How many passes (back and forth) do you generally make until you feel a burr?
[3] Do you make several passes on one side, then flip the blade, or alternate every pass until a burr forms?
[4] I tend to keep the stone at the higher grit.  Should I be using the coarser grit?
[5] Is there such a thing as a general sense of how many passes (per side) it generally takes to sharpening kitchen knives? Five? Twenty five? I've honestly gone way past that sometimes in my frustration.  Feel like I'm flying blind....

Thanks for any info.

Dear Fellow sharpener,

I'm new to the Tormek community but not that much to the sharpeners one.

You ask very clear and meaningful questions. Here are my (poor - lame - personal) answers.

To me there is no clear cut rule about when or what to do with a knife, when sharpening.

Most of the times, I myself sharpen, as you mentioned, kitchen knives. And I sharpen on one side until I feel a burr on the opposite site. BTW about this don't forget to look at what one of our mates here on the Tormek forum published about detecting the but on a bread knife with a cotton bud.

Then comes the question of what steel you sharpen. I usually sharpen German high end steel knives. Which is great and easy to do on the standard Tormek stone. After that, some friends come and ask me if I could sharpen there knives... Well, guys...  The knives are most of the times in a terrible condition and basically made of poor quality steel.

In those conditions, I sometimes cannot feel a burr rising.

About the grit : I mostly use my stone on the lower grit and then take the blade to a wheel that is not endorsed by Tormek... ;-)

How many passes on each side : IMOO just try to  balance the passes.  I have not read any clear opinion about that. I ten to do as follows : very dull knife (my friend's ones - not mine) 10 to 20 soft passes per side, checking for the burr to rise every five passes.Once the burr rises, two passes on one side, then two on the other, then one on each side, very softly. And then the next part of the show on my other machines...

Have fun ! And above all, keep aking and learning.

Regards,