Rock Hard Felt Wheels

[3D Anvil]

Just to add another voice, I've also not had much luck recreating Vadim's results with felt wheels.  Nor did I using paper wheels, which I generally don't like anyway due to rapid heat build up.  I do my post-sharpening stropping on a Ken Onion with the blade grinder attachment.  For common steels, I do a couple passes with a leather belt and 1 micron diamond at +1.5°, followed by a couple passes with another leather belt and PA-70 compound at the sharpening angle.  That usually nets me a sub-100 BESS score, although sometimes it takes a minute or two hand stropping (.5 micron and/or .25 micron) on bass wood to get there.

[kwakster]

Paper Wheels with diamond paste & oil do not overheat an edge.
Vadim's research & testing also proved that.

A Paper Wheel using the standard silicon carbide grit will also not overheat an edge, provided you use enough wax on it's surface so there is  a complete coverage.
This is critical, and the wax is best applied like a crayon on a wheel that is turned by hand.

[HaioPaio]

Vadim has documented his findings here: http://knifegrinders.com.au/SET/Heat_in_Sharpening.pdf

[BPalv]

Paper Wheels with diamond paste & oil do not overheat an edge.
Vadim's research & testing also proved that.

A Paper Wheel using the standard silicon carbide grit will also not overheat an edge, provided you use enough wax on it's surface so there is  a complete coverage.
This is critical, and the wax is best applied like a crayon on a wheel that is turned by hand.

I gotta say, if you pull your knife across the wheel less than 5 mm a second I think you would still possibly hurt the temper.  I think that is documented in Wootz's work.
IMHO it wouldn't take much to heat a quarter micron thickness at the apex.

[3D Anvil]

Paper Wheels with diamond paste & oil do not overheat an edge.
Vadim's research & testing also proved that.

A Paper Wheel using the standard silicon carbide grit will also not overheat an edge, provided you use enough wax on it's surface so there is  a complete coverage.
This is critical, and the wax is best applied like a crayon on a wheel that is turned by hand.

I gotta say, if you pull your knife across the wheel less than 5 mm a second I think you would still possibly hurt the temper.  I think that is documented in Wootz's work.
IMHO it wouldn't take much to heat a quarter micron thickness at the apex.

Yes, if you go too slow you can absolutely smoke an edge, and it also depends a lot on pressure.  Part of my problem is that every paper wheel I've tried has been slightly out of round and it takes some pressure to keep the edge from bouncing.  I just don't see an advantage over leather belts, which produce very little heat.

[kwakster]

The standard Paper grit Wheel using glued on ~180 to ~220 grit silicon carbide can overheat an edge only if too little wax is used while at the same time your sharpening passes are too slow.
If you avoid this i haven't experienced overheated edges, and i have a very simple process to check for that.
I've tested this on various knives (among which a few good quality Tojiro VG10 kitchen knives) well before i told Vadim about Tempilstick, which he then used to do more testing.

Pressure can also play a role; too much will be counterproductive in several ways.
I always recommend to let the Wheel do the work and use a light touch.

On my own Paper grit Wheel i later replaced the glued on silicon carbide grit with glued on diamond grit.
I have found this to work more efficiently on especially high vanadium carbide steel types, plus diamond has the added advantage of a much higher thermal conductivity compared to silicon carbide, a property which very effectively wicks heat away from the apex being sharpened and transfers it directly into the wax which dissipates it further by continuously melting & solidifying during the sharpening process.
Because diamond also has a rather low tolerance for heat you absolutely need a coolant like wax or oil.
I think CBN would be an even better choice than diamond for Paper Wheel sharpening, as it has a much higher tolerance for heat while still having a lot of thermal conductivity (though not as much as diamond)

The combination of diamond paste (which already contains oil) with certain other oils seems to combine these properties even more efficiently, especially when using progressively finer grits, which normally have a higher chance of heat build-up compared to more coarse grits.
Using Paper Wheels with diamond pastes & oil gives me highly polished edges, that also last for quite a while.

I also use my Tormek T7 fitted with an SB-250 stone quite a lot because besides being watercooled & airborne dust free it can also do a few things i can't do (as well) with Paper Wheels.

[RickKrung]

I've been using a rock hard felt wheel with 1µ diamond paste for years with what I am satisfied with as good results, typically around BESS 100, but I no longer check the actual BESS readings as it has been so consistent.  I'm only sharpening standard steels.

Looking through the discussion, I do not see where anyone says much about the other aspects of the setup, some details that Vadim established as important.  Using a Frontal Vertical Base for setting up the USB for clearance and angle control during the honing process. And angles set higher or lower than the grinding angle, depending on the type of steel.  It may be reasonable to assume that you guys are also doing this, but it would be good to know this is the case. 

Because I'm only sharpening standard steels, I'm always using an angle 1º to 2º higher than the sharpening angle, which is usually around 16º.  My grinding steps are 180 CBN, DC, DF, DE Tormek diamond wheels, Tormek SJ and then the rock hard felt/1µ diamond paste and stropping on hanging leather strop. All the grinding steps are done at the same grinding angle, from the read USB, edge-leading.  Only the rock hard felt wheel angle is changed for honing, from the FVB/front USB, edge-trailing.

Hearkening back to this conversation and the two following that related to it (#7 and #11), I decided to do a little testing.  I have about 14 knives from a friend's set of Wusthof Dreizack Grand Prix knives.  I've sharpened these before, all at 16º and it is time for a redo. I wanted to test for any difference between "grinding/polishing" with the SJ wheel at the bevel angle versus 2º greater, both followed by honing on a rock hard felt wheel with 1µ diamond paste and then stropping on a hanging leather strop.  Here are the results:
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First off, I must eat a little crow.  My claims of consistently achieving 100-110 BESS are a bit off the mark, at least with the way it is working for me now.  Not sure what is different, but that is for another time.  One thing that I am unsure of is that I strictly followed the above regiment.  I noticed afterward that the wheel diameter in the calculator for the SJ wheel may have been 254mm (that of my 180 grit CBN wheel and RHF wheel) instead of the SJ wheel's actual diameter of 246.7mm.  Not sure of that, but I have eight more steak knives to do, so if I'm feeling up to it, might try this test again. 

On the the results. 

1) SJ wheel at the grinding angle seemed to produce slightly lower BESS scores than at 2º above the bevel grinding angle.

2) Honing all at 2º higher than the bevel angle improved sharpness for all but the SJ at the angle plus honing showed the lowest scores.

3) Stropping significantly improved the set ground with the SJ at 2º higher and resulted in BESS scores relatively similar to the SJ at the same angle as the bevel.

4) Stropping did not improve sharpness for the blades ground/polished at the same angle as the bevel beyond that achieve only with honing on the RHF wheel with 1µ micron diamond paste.  But stropping did seem to improve sharpness of the blades both SJ ground and honed at 2º above the grinding angle.  These samples are far too limited to make very strong inferences, however. 

Rick

[Sir Amwell]

Thanks for this Rick. Interesting.
From what I understand (and I may be wrong in this) your Bess scores would indicate that complete burr removal has not been achieved. This is not a criticism of you because you have freely given this info at cost of time and effort to yourself to try to answer some questions. Researching.
From somewhere I remember Vadim stating that a score of over 120 Bess is indicative of incomplete burr removal.
So, polishing on the SJ wheel at exact or +2 is not completely removing burr?
Honing on the felt wheel is not removing burr completely either?
And a final strop on kangaroo is also not achieving it?
So I return to my original post on this topic.
Does anyone have success using the felt wheel for honing?
I never did which is why I stopped using it.
I now do much the same process as 3D Anvil mentions,
Whilst the results are a bit variable, they are consistently lower than 120 Bess ( my bench mark, I never let a knife back to my customers above 120), and if I am suspicious about an edge ( paper tests, rizla paper tests, shaving etc), I Bess test and then hanging Roo strop and this usually takes a 140 score to below 120.
For me this is so much quicker and less fiddle faddle than all the felt/ SJ wheel stuff and suits me for batch sharpening of conventional knife steels. Higher end, higher hardness steels just require a slight adjustment of the leather belt honing stage.
Having said all that, what you are doing IS research and therefore valuable so id be interested in any further results. It's all adding to the data base of knowledge and someone will find it useful.
Thanks again.

[RickKrung]

Thanks for this Rick. Interesting.
From what I understand (and I may be wrong in this) your Bess scores would indicate that complete burr removal has not been achieved. This is not a criticism of you because you have freely given this info at cost of time and effort to yourself to try to answer some questions. Researching.
From somewhere I remember Vadim stating that a score of over 120 Bess is indicative of incomplete burr removal.
...snip...

Shucks, isn't that embarrassing...    As you say, it is good information.  I take no offense. 

At some point, I'll have to re-evaluate my process, see if there is something I'm not doing the same, or if something else has changed.  I'm pretty certain I'm getting good burrs all along the edges, so it must be in the honing.  Unfortunately, the best I'll get for a while is to maybe make a few more passes in the SJ and honing steps or more pressure with these remaining knives.  Too much else on the plate and frankly, what I'm getting is good enough for getting by. 

Be well,

Rick

[RickKrung]

Should change the Subject to "SJ Wheel Honing". 

Took another stab at it, but this time, mostly just used the SJ wheel for honing. Eight identical Wusthof Dreizack Grand Prix steak knives.  First one, the SJ wheel was used at the grinding angle (16º) and then the rock hard felt wheel was tried at two angles, 16º and 17º, followed by stropping on a hanging leather strop.  Not much better than before.  Subsequent seven knives only the SJ wheel was used for honing, again at 16º and 17º.  Knives 2-4 were stropped after honing.  Knives 5-8 were honed after 16º and after 17º.  A little mixed up, but hopefully something useful.

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Honing with the rock hard felt wheel degraded the edge, similarly to earlier.  Honing with the SJ wheel at either 16º or 17º followed by stropping on a hanging leather strop, while starting out really high (BESS 250-389) stropping improved to sorta-kinda removing the burr in some cases (BESS 100-120) and almost in other cased (122-136).  Honing with the SJ wheel at 16º and then at 17º does not appear useful, but it is hard to conclude this due to the leather strop honing between those two.

From this, I think I'll dispense with using the rock hard felt wheel and just use the SJ wheel for honing, if followed by the hanging leather strop.  Might be worth trying SJ honing at 2º over the grinding angle and maybe at a negative from the grinding angle (-0.5 to -1º). 

Rick
 

[tgbto]

Rick,

Thanks for the extensive testing and for sharing your results.

This subject of SJ and honing has been of interest to me since my first session with a SJ.

Why do you call what you do with the SJ wheel "honing", when the (300ish) BESS scores clearly indicate that there is still a burr ?

Also, do you know what the BESS scores were right after initial grinding ? Do you think you could get a quick order of magnitude of the BESS score after another grind on the *SG* wheel at the same angle ?

I know that's asking a lot, no worries if you can't. Thank you again for the time you've already devoted to this.

Nick.

[RickKrung]

Rick,

Thanks for the extensive testing and for sharing your results.

This subject of SJ and honing has been of interest to me since my first session with a SJ.

Why do you call what you do with the SJ wheel "honing", when the (300ish) BESS scores clearly indicate that there is still a burr ?

Also, do you know what the BESS scores were right after initial grinding ? Do you think you could get a quick order of magnitude of the BESS score after another grind on the *SG* wheel at the same angle ?

I know that's asking a lot, no worries if you can't. Thank you again for the time you've already devoted to this.

Nick.

That's a good question.  Best I can say is, I was taking the mindset that the SJ wheel could be used for honing, so just called it that.  Was it someone at Tormek that made that claim?  I've always thought of it as polishing rather than honing.   

I don't have much on the scores after grinding, before putting them to the SJ.  369 and 602 is all. 

[BPalv]

Rick,
To start with, thank you for taking the time to compile those numbers.
How do use the rubber bands?
The process I am using is as follows:
I grind most kitchen knives at 15 degrees on the SG-250 unless supersteels. I grate the stone with diamonds plates as necessary and typically finish at what I precieve to be 1000.  I hone on the Tormek honing with FVB with Tormek paste at the exact angle.  (I plan on testing + something).  After 2 passes on the honing wheel I go to a 10" slotted paper wheel with 6 micron pollycrystaline diamonds at +.4 to +2.  Still attempting to figure this out as each steel reacts differently or I'm not consistent in my efforts.  I am using FVB's on the paper wheel setup.  I then go back to the Tormek wheel at the exact angle and using no pressure (knife weight only) make one or two passes.  This usually nets me around 110 most of the time.
I have tried honing with a 1×30 leather strop at a low speed with Tormek paste at the exact angle and on quality steels I usually get 100 or as low as 70.  I have tried 6 micron, 3 micron, 1 and .25 diamond strops but rarely get as good of score as the Tormek paste.
I said all that to ask if the Rock Hard felt wheels would improve my scores but after reading everyone's results I don't think it will.

It seems there are many of us that can achieve 100 with many different ways.  Interestingly no one that has posted on here has stated they can duplicate Vadim's results. 
I have hit 50 a couple times and 70 isn't terribly uncommon but once I get to 110 success seems to become consistent.
I'll keep trying.

[RickKrung]

...snip...
I know that's asking a lot, no worries if you can't. Thank you again for the time you've already devoted to this.

Nick.

Didn't think I'd be back at it with these knives for quite a long time, but it turns out I missed a paring knife and failed to grab a hooked/beak shaped paring knife from the box, so two more today.  Per the request, I meant to get both after grinding and before the SJ.  Only wrote down one, 567, but I'm pretty sure the other one was pretty similar.  Kind of a surprise they are so high. 

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