The BESS Exchange is sponsored by Edge On Up - Burr Removal Methods, Testing and Results

The Burr Transformation in Deburring

Sat, 07 Aug 2021 00:24:17 +0000

ENGLISH

The burr can realign itself???

Sun, 01 Nov 2020 05:34:58 +0000

https://www.dovo.com/en/ratgeber/take-care-of-straight-razors-strops-shaving-brushes/

"To remove leather residue and cut hair from your straight razor, rinse it with warm water. Now carefully dab the straight razor dry with a soft cloth. Please be careful not to touch the cutting edge. Otherwise, you could damage the microscopic burr at the cutting edge. We recommend that you store the straight razor in a well-ventilated place, as this is the best way to protect the metal from tarnishing or oxidation. Since the burr of the straight razor bends slightly during shaving, leave the straight razor to rest for 48 hours. During this time, the burr can realign itself. Rub the blade with an acid-free oil such as a camellia or paraffin oil if you’re not going to shave in near future."

https://www.barberscorner.de/en/blog/care-stropping-of-straight-razors

"The fiber of the linen is soft, the mesh of the textile, however, is rough. This allows the linen to grip the burr and align it. The weave of the textile catches dirt and loose steel particles which could damage the sensitive edge when pressed against the strop. The final use of the strop makes the resulting edge finer. You should strop the razor before, and not after shaving. Steel has a certain level of self-healing power, or “memory.” After stress, the burr slowly and partially stands itself up again. If you violently rip the burr up with the strop immediately after shaving, this stresses the material, which shortens the life expectancy of the burr and, in the long run, of the razor. The razor should rest for at least 24 hours after the shave – but 48 hours or more is ideal, so if you shave every day, you should own at least two straight razors. Our grandfathers therefore often had sets for the entire week, containing 7 razors."

How do you think about that?

What is this Burr Removal process

Sat, 05 Sep 2020 17:52:20 +0000

I'm sure many of you have seen this professional sharpening tower...

Can anyone identify these wheels exactly?
Specifically the two on the grinder just above the belt grinder.

Micro-burr only in one side, and it will not flip

Mon, 17 Feb 2020 01:08:54 +0000

Hello all,
I have a question concerning wire edges on straight razors. For some odd reason i always have a very very small micro burr towards the heel of my razor when I finish honing. I only use 10x magnification and I have a bare/clear incandescent 150watt light bulb over my honing area. The very tiniest burrs can be seen if your under the correct lighting. I understand the art of honing it is to know when to quit honing, but even if everything is done right they may still be microscopic bits of burr/fin that doesn't want to detach from the apex. Some guys recommend dragging the edge through end grain wood, but i think that fractures the edge. I was reading also so will draw the edge through animal horn. I gave tried both and I am not a fan its just not to effective.

I understand the burrs are maybe not hardened steel any more, because the metal has went through plastic deformation. They just don't want to let get(especially the micro ones!) I don't try and aim for a burr while honing straights but it sometimes happens. For example a rather large burr on a knife, chisel etc - when your alternating sides the burr can and will flip from side of side until it is cut off, but with a very tiny micro burr on a knife, razor or any tool - it seems to not flop from one side to the other while alternating strokes, but it tends to stay 'on one side' - these type of burrs that don't flop when alternating side, but stay on one side, well IME even bare leather or linen want coax then off for some reason. I hope that i am making sense! I am not to good at articulating what I am trying to say or write. I like to finish on natural stones, but at times I use synthetic to finish. My sequence is 1.5k, 5k, then Jnat, with koma sluuy and last tomo. I like my razor to at least pass a hht1-2ish after stropping at 5k, and I try to make sure there's no burrs at 5k, but sometimes they are very very micro. My question is what do you think of stropping on bare wood, with no compound? Not just any wood but one of the hardest wood on earth (lignum vitae?) Does this sound like a crazy idea? I figured a really hard wood would cut off any bits of detached burr?? IMO this doesn't look like a normal wire edge but it looks like fuzzy glints only in sections, if that makes sense. How can something so weak be so hard to coax off? I figured the lignum wood may help remove it, because of its lubrication properties and it's hardness may help??

Thanks
Mike

Toothy edge - Scotch brite belt(1)

Tue, 13 Aug 2019 01:13:40 +0000

I used worn Blaze 120 grit(about 15 degree), and Super fine scotch brite belt.(higher degree)

190813093651576.jpg (Size: 1.05 MB / Downloads: 20)

190813093602482.jpg (Size: 1,015.92 KB / Downloads: 19)

Center sharpness: 197, 301, 209 BESS.(Average is 236 BESS)

Fail

New burr removing method - Felt block

Thu, 25 Jul 2019 06:49:16 +0000

https://www.youtube.com/watch?v=0CL4okt-QxA

Disposable Razor Maintenence

Sun, 03 Feb 2019 12:25:42 +0000

I got out my new 60x kingmas viewer and looked at my Excel razor...both a used one and a new one......I wish i could post images for you all to see!

This lead me to a 30 min journey on the internet to find that people actually STROP their used blades......someone built a handsome denim box.....someone uses green compound on a peice of plastic.....and a company in the UK makes a silicone pad and some magic sauce to sell as a Razor strop to save you hundreds of dollars per year!

Here is the link:

https://www.razorpit.com/

Has anyone on here that lives for a sharp blade done an investigation?

Can you really do much more than clean out the crud?

Have you done it yourself??......What really works well?

I go thru alot of blades, so this sort of thing appeals to me.

I would also like to dissect a blade, and test it but doubt I could pull it off as those little blades are so delicate.

Sam

Wire Edge Prevention

Mon, 03 Sep 2018 07:55:33 +0000

Inspired by the thread by Mike and Grepper http://www.bessex.com/forum/showthread.php?tid=371

What wire edge is

Well-known 2 steps in sharpening a knife are apexing and deburring, and deburring is more challenging since it determines how sharp and stable your edge will be.

There is one very special zone at the base of the burr, right between the burr and the apex, designated as LOW on the below optical microscope image showing layers of the burr (the image is from the above thread).

After you deburr the edge, the base of the burr turns into the wire edge.
The wire edge is often regarded as a structural continuation of the apex – it is its sharpest but also the weakest structure. From a logical standpoint this poses straightforward reasoning – the burr formation is the result of plastic deformation, why would one expect the steel at the base of the burr stay the same as the apex?

In the ultra-sharp sharpening we distinguish more steps in deburring, namely: exposing the base of the burr also known as wire edge, and cleaning the apex of it.

The following optical microscope images show a burr off a coarse abrasive that is easily felt by brushing a finger across the edge, and next to it a blade with the wire edge that you cannot see and cannot feel. (By courtesy of Tony Spielberg, USA)

The wire edge on SEM edge-on view (all SEM images are by courtesy of Todd Simpson scienceofsharp.wordpress.com)

“Feather burr” and “Foil edge” are two more edge geometries that can be created in the finishing stage of removing the burr – these two are near synonymic and are a product of edge-trailing honing at the edge angle; shown on the following optical and SEM microscope images.

We can recognise presence of the wire or foil edge by the edge behaviour in cutting stuff.
An obviously ultra-sharp edge that whittles hair will start a smooth cut but end with tearing, or show clean cuts alternating with ragged - indicating a weak edge folding in the process. If the edge is not cutting well, it can only mean two things: either it has not been fully apexed, or there's a burr or crushed wire/foil edge getting in the way.
The wire edge crushes under a minimal load by mushrooming seen on SEM microscopy.

What we see on the BESS sharpness tester?

Because the wire edge is too weak to cut the test line, it crushes on it and, as we increase the downward pressure, mushrooms against the line allowing to apply more pressure onto the widening point till the line gets finally severed – in the point of testing we see a micro-dent in the edge with the mushroomed apex displaced to the dent bottom, and the sharpness reading is times worse than we would expect by seeing the same edge whittle hair and push-cut rolling paper.

A knife that fails early is the result of a wire edge that hasn't been properly removed.
A good sharpener knows how to apex and deburr the edge; an expert sharpener knows how to clean the apex of the weak wire edge not rounding it.
The wire edge is very common in edge-trailing deburring as too often the base of the burr is not removed completely. It is just so fine that it is not detected by the 'finger method' most people use. The end result is the wire edge that dulls extremely quickly once the wire gets mushroomed with the first cuts.

How do we clean the apex of the wire edge?

It's a bad idea to simply draw the edge through a wood block, rubber or cork to “rip off” the wire edge. If you do, the metal crud will build up on the front of the slice, and you'll be dragging the rest of the edge through the crud and this, together with breaking off of ledges of material along the edge, will roughen the edge and worsen sharpness.

An edge-leading pass on an ultra-fine bench stone can accomplish the wire edge removal, but at the risk of micro-chipping and abrading off the apex when done by inexperienced hands. A shortfall of this method is that you are introducing a new microscopic burr.

We remove the wire edge by honing with fine diamonds or CBN and raising the honing angle very slightly, from 0.4 to 2 degrees – the softer the steel, the higher the angle. The edge only needs to “sink” the apex into the compressible material, and you can do this on leather, balsa, hard felt or a paper wheel just as easily as on a hanging denim strop loaded with a fine honing compound – the microscopic diamonds will cut at the base of the burr.

Only once you eliminate the base of the burr, there is no more wire edge. A correctly deburred edge shows nothing except the clean scratch pattern going to the end of the apex.
Optical and SEM microscope images of a cleaned edge follow.

Uncertainty

Methods to assure completeness of deburring and removal of the wire edge we have at our disposal, on the one hand, and the miniscule nature of that edge on the other, bring us to the point of uncertainty, IMHO.

In all honesty, where a freshly sharpened edge scores over 100 BESS we can not tell for sure whether this results from some residual wire edge or not – because at this BESS score only SEM imaging is able to exclude the weak apex mushrooming against the test line.
Only when the BESS score taken on the standard test media line is near 50 BESS, i.e. that of uncompromised DE razor, we can be absolutely sure that the edge apex is clean of the wire edge, and this is the only instrumental indicator we have readily available at present.

Experiments on wire edge removal

I experimented on a budget stainless steel kitchen knife - WiltShire brand.
We know these knives as producing that nasty malleable mutant burr that is very difficult to clean off, and I used to be happy if I could get them score 170 BESS.

Sharpened on Tormek, the edge was set at 13 dps on #1000 CBN wheel.

Then honed on a paper wheel with 5-micron diamonds at the edge angle - honing mainstream stainless steels this way invariably produces a microscopic feather burr, similar to pictured.
At this step we thin away the original burr and gain access to the base of the burr.

The top layers of the burr are removed but leave the base of the burr intact and still stuck to the edge in the form of the wire edge. The wire edge, by its genesis, is the very first layer of the burr laid down and is really well stuck to the edge apex. We think this layer at the base don’t flip with the rest of the burr in the process of deburring.

I then cleaned the hardly visible fine feather burr on a rock-hard felt wheel with 1-micron diamonds on Tormek, using our Frontal Vertical Base for honing away from the wheel, similar to shown on the next picture, only in place of the legendary AL MAR imagine the cheap WiltShire kitchen knife.

The experiment plan was in repeating the sharpening-honing-cleaning sequence, gradually raising the felt honing angle, and recording the resulting BESS scores.
Grinding and honing angle was controlled with our computer software for Tormek and paper wheels.

Off the #1000 CBN the edge burr scores 250 BESS.
After the 5-micron diamonds paper wheel the edge feather burr scores near 500 BESS; micro-denting is easily detectable in the point of testing. The high BESS score is result of the feather burr crushing and mushrooming against the test line.

Now 1-2 passes on the felt wheel with 1-micron diamonds on Tormek, alternating blade sides.
At this step we hone away the flimsy feather burr and clean the apex of the wire edge.

Felt wheel at the exact edge angle = 100 BESS
Felt wheel at +0.4 degree higher angle = 80 BESS
Felt wheel at +1 degree higher angle = 175 BESS
Felt wheel at +1.5 degree higher angle = 140 BESS
Felt wheel at +2 degree higher angle = 80 BESS
Felt wheel at +2.5 degree higher angle = 120 BESS

I then repeated the two best results, i.e. re-sharpened the edge on #1000 CBN, honed on the 5-micron diamonds paper wheel at the edge angle, and then on the felt at +0.4 vs +2 degrees higher angle, after the felt wheel finishing the edge on a paper wheel with CHROMOX for final cleanup.
Felt wheel 1-mcrn diamonds @ +0.4 degree = 90 BESS >> CHROMOX = 100 BESS
Felt wheel 1-mcrn diamonds @ +2 degrees = 80 BESS >> CHROMOX = 55-60 BESS, hair-splitting.

We see that for the lower-end mainstream stainless steel the best cleaning of the apex is achieved by high-angle honing at 2 degrees higher than the edge angle.
In this case, the edge set at 13 dps, we cleaned at 15 dps, and by the BESS score near 50 BESS we seem to have cleaned off the wire edge.
For that lower end s/s steel, 55 BESS is a record sharpness score on an obviously stable edge.

How I interpret the other failed sequence of "Felt wheel 1-mcrn diamonds @ +0.4 degree = 90 BESS >> CHROMOX = 100 BESS" - I think it tells us that the base of the burr had not been honed away completely on the felt, and the paper wheel with CHROMOX, rather than cleaning the apex, added volume to the remnants of the wire edge, turning it into the foil edge; when it pressed against the test line and mushroomed we saw that increase in the BESS score.

How I interpret changes in the BESS score with the raise of the honing angle on the felt:
Felt wheel at the exact edge angle = 100 BESS      <- feather burr removed, we are nearing the base of the burr
Felt wheel at +0.4 degree higher angle = 80 BESS <- the base of the burr exposed
Felt wheel at +1 degree higher angle = 175 BESS   <- adding volume to the base of the burr through burnishing
Felt wheel at +1.5 degree higher angle = 140 BESS <- adding volume to the base of the burr
Felt wheel at +2 degree higher angle = 80 BESS     <- the base of the burr cut off, the apex exposed
Felt wheel at +2.5 degree higher angle = 120 BESS <- rounding the edge apex

The "Toothy" Burr

Thu, 30 Aug 2018 18:11:55 +0000

If you're a convert to "toothy" edges like we are then proper burr removal becomes the center of your world. We like toothy edges because they are easy and fast to create using, typically for us, a single grind process with a 80 - 180 grit ceramic belt on the Kally. The actual grinding process may take only 30 seconds to a minute. Now the work begins though, proper removal of the burr and removal of certain elements and artifacts of the burr can be a real challenge. The goal is to remove the burr completely without significantly reducing the tooth in the edge. We've been experimenting here with faster and surer methods of getting from A to B and the first order of business for us is to understand, as completely as possible, what the constituent components of burr formation are.

Burr formation does not appear to be some cataclysmic event. Formation of an easily recognizable burr seems to be a process. While there are those who seem capable of "seeing" a burr at its earliest formation stages we do not count ourselves among them without the aide of magnification.  In practice, we have to rely on "feeling" the burr. What we have learned is that burr formation begins long before any of us can actually detect it tactilely.

We designed an experiment that builds on the work already established by our good friend Grepper. Grepper has shown us the enemy through his microscopic work many times in other threads. In our communications with Grepper we have non-affectionately named this enemy "LOW" or "line of weld". This is not because it is a "line of weld" but rather because it has the same appearance as a "line of weld". It is a booger indeed. Visible only via properly lighted microscopy, stout and firmly attached to the edge apex. Proper removal of this LOW will result in a 50 - 75 point improvement in BESS scores. Here's is a LOW image taken by Grepper with text added by us;

  Mark Layers Text.jpg (Size: 129.53 KB / Downloads: 49)

These layers are stuck together somewhat but not firmly bonded. When normal deburring methods are employed, more often than not, the top layers of burr are removed but leave the LOW intact and still stuck to the edge. The LOW has such a low profile that subsequent deburring attempts using common methods and materials are unable to pick it up and stand it up so that it can be removed. It can be picked up though and just to be prove it, Grepper performed this little trick and then took the photo. He used the point of an exacto knife to pry the burr up. We tried the same thing with the corner of a DE razor blade but it wasn't stiff enough to turn the LOW over. A single edge razor blade was and we were successful in standing the LOW up in the same fashion that Grepper had. Here's Grepper's picture with our remarks;

  Mark Exacto Text.jpg (Size: 127.19 KB / Downloads: 54)

The LOW seems to be the first layer of burr laid down and it seems to be really well stuck to the side of the edge. It's also well attached to the edge apex. Subsequent grinding passes just seem to add to the volume of the burr. To support this theory we ran the following experiment. First we set the rest on our Kally at a fixed angle and then sharpened a knife and removed all the burr including the LOW. We did no leather refinement to the edge which seems to always be good for another 30 or 40 points but still the edge measured 150 and 155 and even though the belt we used was 80 grit.
Then we ground this already sharp edge again. But first we colored the edge black (grind side) with magic marker to make certain that the belt removed metal all the way to the edge. We made just one very light pass on just one side of the edge. There was no detectable burr present. Then we took a picture of the ground side.

  Mark ground side.jpg (Size: 145.63 KB / Downloads: 46)

Not much to see other than the residual of the black marker buried in the grooves of the original grind marks.  So we flipped it over for a picture of the opposite side of the edge;

  Mark Op side 1 pass.jpg (Size: 235.77 KB / Downloads: 44)

And there we find a nicely formed LOW. Any subsequent and additional passes with the belt will add to the volume and height of this burr. As the burr is flipped back and forth during the grinding process it grows until it can be readily felt with a thumb. In the picture above, we couldn't feel it. If you strop the LOW on leather pad or belt it usually won't come off. If you persist and are finally able to remove it, a significant amount of tooth will be lost in the process. We are working with Grepper on ways to efficiently remove the LOW while preserving tooth and some methods do show a lot of promise. More on that later but in the meantime, we have identified the enemy. Grepper recently reported in an Exchange thread sub 100 BESS scores on a very average knife. In that case, proof that the enemy can be defeated.

Hardness and Ease of Deburring

Sat, 18 Aug 2018 10:44:16 +0000

Many thanks to Mike B. for the A2 blades - they keep us entertained with testing this weekend.
A2 tool steel is high carbon, high molybdenum.
The A2 blade #7 has been hardened to HRC 54, while the A2 blade #11 to HRC 62 - they represent extremes of the knife hardness range.

This simple study is to compare how the blades differing only by hardness respond to deburring.
These two blades have been sharpened exactly the same way, and edge sharpness scores recorded through the process.

The results have come with no surprises: the harder steel is easier to deburr and get sharper.

The blades were bevelled at 15 dps on Tormek using CBN wheels, the edge set on CBN #1000 edge-leading.
Off the #1000 CBN wheel a tiny burr was visible.

Deburring was done on a paper wheel with 5 micron diamonds at the exact edge angle, i.e. 15 dps, with the help of our support for controlled-angle honing and computer software.
Finished on a paper wheel with 0.5 micron diamonds to see effect of burnishing.

5 microns correspond to JIS #3000, and 0.5 micron to # 30,000

In the context of this study, higher BESS numbers indicate a larger burr.

SHARPENING STEP - HRC54 - HRC62 (BESS sharpness score)
Off #1000 CBN - 197 BESS - 159 BESS

Paper Wheel with 5 micron diamonds at 15 dps
2 passes alternating sides - 193 BESS - 138 BESS
4 passes alternating sides - 187 BESS - 127 BESS
6 passes alternating sides - 127 BESS - 72 BESS

Paper Wheel with 0.5 micron diamonds at 15 dps
1 pass alternating sides - 321 BESS - 114 BESS << burnishing effect - in the softer steel more metal gets displaced over the edge apex, forming a wire edge.

Paper Wheel with 0.5 micron diamonds at 15.4 dps i.e. higher-angle honing at 0.4 degree higher
1 pass alternating sides - 109 BESS - 95 BESS
final sharpness

That's it, only will have to update this post with sharpness scores taken in 24 hours to see if there is difference in the post-sharpening spontaneous dulling.

HELP FROM NORWAY

Mon, 02 Jul 2018 18:49:36 +0000

We're looking for help from one of our Norwegian customers. We have been contacted by a Norwegian knife reviewer who would like to include edge testing as a subject of one of his reviews. He is asking if someone in Norway would be willing to share an edge tester with him. He is located in Sarpsborg in østfold .

If you're able to help you may reply here or by PM'ing us. Thanks!

Should the edge be horizontal?

Sat, 24 Feb 2018 05:32:05 +0000

Sometimes, the fulcrum causes the knife edge to fall out of level. Is it OK to measure like this?

IMG_3703.JPG (Size: 469.27 KB / Downloads: 13)

Welcome to SHARPCO!

Sat, 20 Jan 2018 17:40:11 +0000

SHARPCO is our newest international distributor and is located in South Korea. SHARPCO is a highly respected supplier in the region and a well known and important authority within the regions knife sharpening industry. Thank you to SHARPCO for joining in with us on the BESS Exchange and we look forward to hearing more. Please give SHARPCO a BESSEX welcome!

A mutant burr

Fri, 15 Sep 2017 03:43:52 +0000

I was down to only one sacrificial knife for testing and experimenting, so I went to the local Salvation Army store to see if they had anything interesting. Occasionally I get lucky and find something nice, but this time not so much. 90% of the knives were worn out serrated pieces of that shiny stainless spring steel crap, whatever that stuff is. I did find one 7” Santoku for $1.99 and a little 3.5” paring for $0.99. The steel seemed to be the next step up from the shiny spring steel stuff, but nothing special at all.

I decided to sharpen them both with a new, unused 120 grit Cubitron II belt because I wanted to break in the belt. When those belts are new they are extremely sharp and aggressive, but calm down to just right after break in.

The cheapo little paring knife couldn’t take such a coarse abrasive and the edge just crumbled away in chunks rather then getting sharp. I didn’t really care, so I bailed and moved to the Santoku which was far more interesting.

The Santoku had no problem with the coarse abrasive and formed a large, heavy duty burr. I started deburring with light pressure, 45° angle strokes on the rough side of a leather belt. It was easy to see the burr bending back and forth. I did that for awhile. Then a while longer. The some more. The burr just kept bending and bending and bending…

So then I started applying more pressure and counted 26 strokes on each side, plus some occasional strokes at almost 90° to the belt. After that the burr seemed mostly gone, but under a good light I could still see a hint of burr. I took 3 sharpness readings: 150, 155, 165. So I deburred more. A lot more. Maybe another 20 on each side. That kind of thing. Then I took readings again: 140, 145, 150.

Every so often I run across a blade like that. Whatever that no-name steel is, it creates an extremely malleable burr that is highly resistant to deburing. Far, far more difficult and time consuming than most knives. Almost like the burr was made of gold. The stuff just bends and bends and bends and bends and… It’s almost flabbergasting. How can such a thin little piece of steel be so resilient? Had I not seen it before, I might have even been gobsmacked.

I guess it just goes to show that no two burrs are created equal. It also shows the importance of carefully checking that the entire burr is removed as the effort required for complete burr removal is potentially highly variable from blade to blade.

Homemade cryogenic deburring machine?

Thu, 31 Aug 2017 02:39:16 +0000

If I got a tank of liquid nitrogen, could I get a blade cold enough to:
http://www.arrowcryogenics.com/cryogenic...-deburring

The Deflashing and Deburring Process
Using liquid nitrogen during our deflashing and deburring process, components are lowered to a temperature that allows the material to become brittle. Then, utilizing our cryogenic deflashing machines the flash and burrs are easily removed without altering the finish on the parts.

How cold would steel have to be to become brittle enough affect deburring?

How about dry ice? How about just sticking it in the freezer?

Would the blade edge instantly warm too much the moment it was removed from the source of cold?

After looking around a bit, I guess storing liquid nitrogen is not exactly practical. Dry ice a cheap though and apparently you can purchase various cryo freeze stuff in handy cans.

This is probably a really silly post, but it got me wondering.

Deburring with a 3M Talc belt

Fri, 25 Aug 2017 00:42:23 +0000

Mr. Rupert most magnanimously sent me a 3M Talc belt to test to see how well it works for deburring.   Thank you Mr. Rupert!

My main interest in testing it was to discover if it might be a more efficacious solution than the leather belt I normally use. The leather belt actually works very well for deburring, but it takes some practice and deburring must be done with care to remove burr on a toothy edge with a minimal amount of tooth smoothing. I keep searching for something I can just jam a blade into, do a couple of swipes and automagically have a nice, burr free edge with little or no smoothing of the toothy edge.

The surface of the talc belt is a fuzzy layer on a firm but slightly forgiving base. Unfortunately this particular belt has a manufacturing defect where one of the two but joints was not properly glued and filled in so the belt is held together by only the tape on the back of the belt. I was a little worried the thing might break, but because the Kally is a fairly slow 1x42 grinder generally the only damage done when a belt pops is that it is slightly startling. Here you can see the fuzzy surface of the 3M talc belt and the thickness of the subsurface.

  belt.jpg (Size: 19 KB / Downloads: 8)

For consistency I used a 150 grit Cubitron belt for sharpening and raised a fine little burr visible to the unaided eye.

  burr1.jpg (Size: 14.6 KB / Downloads: 9)

My normal procedure when using the leather belt is to first make 2 or 3 light passes at the angle of sharpening. (1 pass = 1 swipe each side). I do this to make sure the burr is straight and not mashed down on one side of the edge. Then, holding the blade at almost 90° to the belt, very lightly swipe the length of the blade against the belt, doing this on both sides of the blade. This forces an almost 90 ° bend in the burr which I hope aids in stress fracturing the burr. Then I do a couple of passes at the angle of sharpening to bend the burr again, wipe it a few times on my jeans to clean the edge of dust and junk and I’m done. This generally does a pretty good job of burr removal with a minimum amount of smooth of the edge.

So, I did the same thing with the talc belt. Here is an image of the blade after the first couple of passes a sharpening angle. You can see that the passes at sharpening angle do a good job of getting the burr to stand straight from the edge.

  burr2.jpg (Size: 35.64 KB / Downloads: 13)

Then I completed the procedure with the 90° swipes, sharpening angle passes and jean wipes. Here is the result. Still lots of burr.

  bur3.jpg (Size: 26.2 KB / Downloads: 13)

Bailing on the talc belt, I used the leather belt. Here’s what it did.

  burr4.jpg (Size: 28.24 KB / Downloads: 17)

A sharpness test on the PT50B after the leather belt yielded 145 gf. About what I would expect. Unless something has gone horribly amiss, this process almost always produces a 130 gf -150 gf edge. I’ve done this so many times now, and it works so consistently, I can pretty much predict the sharpness reading, but I always take one anyway cuz I just like using the PT50B.

I suspect the talc belt is designed for polishing after loading it up with compound. I really had my hopes, but for burr removal, at least in this one test, I found it less effective than a leather belt. Alas, the search continues...

Burr removal - Least agressive compound that still works?

Sat, 10 Jun 2017 04:39:42 +0000

I suppose this question is mostly for Mr. Mark because I know you have a lot of experience with compounds, but anyone who has an opinion please chime in!

I’m looking for the least aggressive honing compound to aid in burr removal. I love toothy edges and don’t want to smooth them trying to remove burr, but I’ve found, at least I think, that a bit of compound seems to expedite burr removal using the rough side of a leather belt.

I currently use Tormek honing compound, supposedly 1 – 3 micron, AO. It actually seems to help, but I’ve noticed some edge smoothing. Not much, but some.

I could care less about a polished bevel, I just want to remove burr as quickly as possible without edge smoothing. Hence my search for a less aggressive honing compound that still works. Maybe I'm asking the impossible!

From your experience, what is the finest, least aggressive compound that seems to aid in burr removal?

Why are burrs so malleable?

Sun, 04 Jun 2017 04:39:26 +0000

I’ve been doing a bunch of experiments with burr removal and I’m puzzled.

Does anyone know why some burrs are so !@#$!$’ing malleable?

I’ve had burrs that I can bend over and over and over and over… again at 45 degrees and they are extremely resistant to fracturing. They almost refuse to fracture and break off. Additionally, even thought I didn’t do it, I’m sure that if I did the same thing with the blade itself it would break after only a few bends.

The thing that is really a head scratcher is that burrs are really very thin, but they seem to have the malleability of gold and are far more malleable than the blade itself.

I was reading on the Science of Sharp website where the author was talking about stropping 300 – 500 strops on the extremely thin metal on the edge of a razor blade. 300 – 500 strops on edges only a couple of microns thick! Why is that?

I’ve had a lot of experience with stress fracturing metal. It always seems to happen when I don’t want it to. Bolts break in half, some piece of metal I’ve bent cracks or fails under normal use with what would seem to be not that much stress. Yet with a burr, when I want it to fracture and break, that extremely thin little sliver of steel is amazingly fracture resistant.

I’m guessing that something happens to the metallurgy of the steel when the burr is formed. Perhaps Mr. Jan or Mr. Mark can chime in and help explain this odd metal behavior.

buffing speed

Fri, 14 Apr 2017 10:20:23 +0000

I remember finding a statement by a sharpening source who, after testing, determined that, in his opinion, the ideal speed for a moving leather honing belt or wheel was approximately the speed of a Tormek.

I apologize for not being able to source this better; I have forgotten the name of the source. Perhaps someone on the forum can help out.

I am presently just beginning to test an 8" x 1" Duro Felt (hard grade) buffing wheel. I am using it on my Tormek T4, which uses eight inch (200mm) diameter grinding wheels. The felt wheel has a one inch bore opening. I have it mounted on a steel one inch to twelve mm reducing bushing.

I debated between the hard and rock hard grades. If the hard tests well, I may add a rock hard.

My initial problem has been slippage.

My wife and grandchildren have awoken; I will return to this post.

Back.... The slippage issue is somewhat due to needing spacers to bring the one inch felt wheel to 40mm. 12mm fenders, readily available, should solve that. I remember they work better on one side of the grinding wheel. I don't remember whether that is the inside or outside. (50-50 chance of getting it right on the first attempt).

I would also like to glue the felt wheel to the steel bushing. Any glue suggestions?

Next issue will be choice of honing compound.

I do not know if this will work well or not. Nothing ventured, nothing gained. Comments welcome.

Ken

Where to purchase honing compound?

Sun, 09 Apr 2017 02:26:17 +0000

The earlier honing compound topic is going so well that I did not want to break the momentum with a low tech question.

I plan to purchase a leather honing belt during the free shipping period at Lee Valley, which ends on the 18th. Where is a goid place to purchase one of the newer honing compounds?

Thanks,

Ken