Finer Points of Burr/Wire Edge Removal

[RickKrung]

Below are several threads from the BESS Exchange on the finer points of burr and wire edge removal necessary to achieve sharper and more durable apexes on our knives, that I have found very interesting and helpful.  I have not yet implemented any but the techniques proffered by Knife Grinders (Wootz on our Tormek forum) in the last one is what I find most informative and helpful and I do plan/hope to follow. 

Link posted by Knife Grinders (Wootz on our Tormek forum) on the BESS Exhange
http://bessex.com/forum/showthread.php?tid=373

Article by Larrin Thomas referenced/linked in KG's post above
https://knifesteelnerds.com/2018/08/27/what-is-edge-stability/

CATRA Testing on Edge Retention Embedded Within the Above Thomas Article
https://knifesteelnerds.com/2018/06/18/maximizing-edge-retention/

Wire Edge Removal Discussion on Bess Exchange Initiated by KG
http://bessex.com/forum/showthread.php?tid=372

Rick

[stevebot]

My hat is off to these researchers for their fine work. The research I did 20 years ago is primitive by comparison. Long live the new experts.

[wootz]

My hat is off to these researchers for their fine work. The research I did 20 years ago is primitive by comparison. Long live the new experts.

Your compliment is much appreciated Steve. Wherever we are now, we all started from your Sharpening Made Easy book.

[Scott an Edge]

I've been having burr removal and edge longevity issues for a while and I thought it time to pose the question on the Tormek forum. Luckily I found this info from the Knife Grinders crew! Well explained and researched info with fantastic pics to help with the technical explanations.
Thanks to all contributors.
I now have a better idea of what may be wrong and what to look for. This is the first step in fixing the issue and modifying my technique.
Now all I need to do is convince the wife that I need a scanning electron microscope!

Given that the Tormek grinding wheel is almost always a different diameter to the honing wheel, what is the easiest way to ensure the grind and hone angles are the same?

Cheers Scott

[Ken S]

Scott,

There are several ways to compensate for the diameter differences in wheels, including the leather honing wheel. They range in cost from free to very reasonable, depending on the desired accuracy.

The most accurate method is to use the applet from knifegrinders.com.au.  This inexpensive program is inexpensive, very accurate, and easy to use.

For general use, my preferred method is the kenjig. (Caveat; I am Ken.) If you use one or two angle settings, say 15° and 20°, this very simple method is very fast and reliable. If you use different settings and/ or wheels, the Knife Grinders applet is your best bet. Forum member Rich Colvin has placed the kenjig instructions in his Sharpening Handbook, as well as the grinding angle tables designed by Dutchman of this forum. Dutchman's work is the basis for the kenjig, as well as most of the firum jigs.You can reach this valuable free resource from his member name on this forum. I refer to it often.

The other choice is the Anglemaster. For a long time, I found the Anglemaster tedious. As I have added more flat ground knives (instead of the traditional bolstered taper ground knives) I have found the Anglemaster more user friendly, especially if I use it with a substitute target. A substitute target is two thickness of gift cards with the same jig Projection as the knife blade. This presents a nice flat surface for the Anglemaster.

If you envy the kind of sharpness achieved by Wootz (Knife Grinders), get his applet. He has provided excellent video instructions.

Ken

[cbwx34]

For the computer program... there are iOS alternatives available, (links in my signature)... if you don't have an Android phone.  You can also try a free version from Rich Colvin HERE.  All based on Dutchman's work... LINK.

RickKrung has revived an older idea and built a tool for easily setting the angle on different wheels... LINK.

But, while I think the jigs and the "computer versions" may be more accurate (and probably more consistent)... IMO, it's not always necessary.  Merely honing at a bit higher angle, (which can be done freehand) will in most cases, adequately debur an edge.

[Scott an Edge]

Ok, I've had a bit of a thought on the USB height and the difference between grinding and burr removal on the leather wheel.....
There are a lot of clever people doing lots of clever things with cosine, calculators and contraptions. All in search of the repeatable perfect desired angle. This all fascinates me and I will delve into it all in good time. Thanks CB for the links in your signature block.
However, while sharpening my mother-in-laws knives on the w'end I was simply matching the knives original angle using the marker method and wanted to set the same angle for burr removal then raise the angle slightly to remove the wire edge burr - thanks for the KG info RickKrung.

So thinking as simply as I could for a repeatable and accurate USB setting for the Leather wheel I did this;

Grind Diameter 248mm = Radius 124mm
Leather Diameter 215mm = Radius 107.5mm
124 - 107.5 = 16.5mm

Measured the USB grind height, subtracted 16.5mm, bingo, should now have the same angle for burr removal - as long as I don't care what the exact bevel/edge angle was in the first place this method should give me a matching angle for burr removal. Then all I do after initial burr removal is crank up the micro adjuster in line with the KG info to give me a clean edge.

Tried this on one of the knives that was proving to be difficult to cleanly remove the burr and it worked a treat - one of the sharpest knives I have produced so far.

The biggest problem I have is that I keep running out of knives to sharpen - the T-8 is too quick.
Cheers Scott

[Jan]

Scott, I am afraid that setting the correct USB height for a wheel with different radius is more complicated because it depends on bevel angle and projection distance also.

It is easy to check with the Angle master if your procedure sets the desired angle. 

Jan

[Scott an Edge]

Gday Jan,
I agree that it is not quite that simple.
I drew some circles and triangles, remembered some high school trigonometry and realised my method was not precise - but it wasn't off the charts out of whack either 😉.

Next time I sharpen a knife I will check for the error with the Angle Master as you suggested.

Cheers Scott

[Jan]

Scott, you are welcome! 

Jan

[cbwx34]

Ok, I've had a bit of a thought on the USB height and the difference between grinding and burr removal on the leather wheel.....
There are a lot of clever people doing lots of clever things with cosine, calculators and contraptions. All in search of the repeatable perfect desired angle. This all fascinates me and I will delve into it all in good time. Thanks CB for the links in your signature block.
However, while sharpening my mother-in-laws knives on the w'end I was simply matching the knives original angle using the marker method and wanted to set the same angle for burr removal then raise the angle slightly to remove the wire edge burr - thanks for the KG info RickKrung.

So thinking as simply as I could for a repeatable and accurate USB setting for the Leather wheel I did this;

Grind Diameter 248mm = Radius 124mm
Leather Diameter 215mm = Radius 107.5mm
124 - 107.5 = 16.5mm

Measured the USB grind height, subtracted 16.5mm, bingo, should now have the same angle for burr removal - as long as I don't care what the exact bevel/edge angle was in the first place this method should give me a matching angle for burr removal. Then all I do after initial burr removal is crank up the micro adjuster in line with the KG info to give me a clean edge.

Tried this on one of the knives that was proving to be difficult to cleanly remove the burr and it worked a treat - one of the sharpest knives I have produced so far.

The biggest problem I have is that I keep running out of knives to sharpen - the T-8 is too quick.
Cheers Scott

I'll repeat what Jan said... your method is not accurate... although it seems that it would be.  That it worked is merely a coincidence... and probably won't over time.

Like Jan said, there are several variables, but for an example... if you take a standard knife at 15°, and applied your idea... you would actually be honing around 12° on the leather wheel.  So, when you "cranked up the micro adjuster"... you were then probably honing close to the actual angle.

So, an alternative theory, (why this worked "better" than before, and gave you the best edge so far)... you might have been "overhoning" before, and/or rounding off the edge.... or maybe overpolishing it.  (Depends on what your "test for sharp" method is too).

p.s.  When word gets out you sharpen... you'll have enough knives to practice...

[Scott an Edge]

Jan & CB,
You are both 100% correct 😀

I took my ball park figures and compared them to the calculated figures and yes, my 'crank it up' method was simply correcting my original error. The reason I looked in this thread in the first place was because my honing and burr removal was below par.

My 'method' was definitely not repeatable with any degree of accuracy.

What is the ideal amount of honing paste to use? I usual run a thin line around the leather wheel, smear it across the surface with a piece of flat metal then start honing. Occasionally I scrape off the old paste.

Thanks
Cheers Scott

[cbwx34]

Jan & CB,
You are both 100% correct 😀

I took my ball park figures and compared them to the calculated figures and yes, my 'crank it up' method was simply correcting my original error. The reason I looked in this thread in the first place was because my honing and burr removal was below par.

My 'method' was definitely not repeatable with any degree of accuracy.

What is the ideal amount of honing paste to use? I usual run a thin line around the leather wheel, smear it across the surface with a piece of flat metal then start honing. Occasionally I scrape off the old paste.

Thanks
Cheers Scott

Thanks for the update.  (If you look thru my posts, you'd find I spent a lot of time on calculation stuff... if I hadn't, I would have thought your original idea made sense).

For honing compound... my personal method... I run a bead around the wheel, then with the wheel off, I rub it in with a toothbrush.  This seems to last me quite a while... but I use the leather wheel just enough to debur the edge... I don't really polish on it (that might take more frequent applications of the compound), so it depends on the goal.