With mention of the Tormek honing compound. The results may surprise you.
http://www3.telus.net/BrentBeach/Sharpen/Stropping.html
I found this excellent article very interesting Grepper. Thanks for posting it. The author's conclusion seems to somewhat endorse Tormek diamond paste and the strop wheel method. The edges on my first chisel and plane iron seemed to benefit quite a bit from stropping on the leather wheel. I have had mixed results with stropping by hand on leather, but I did get better at it with time. I learned to be a lot more careful than when I first started because I ruined so many edges with bad technique. I find it interesting that one guy didn't like the Tormek diamond paste and was using the Lee valley green which was discussed in the article. I can't remember where I read that, but it was recently. Maybe a Tormek review, not sure.
I found that very interesting too, Mike.
The thing about the Tormek compound is that it is very fine, and pretty consistent in size, 1 – 3 microns, where other crayons have much greater variance in abrasive particle size. Considering that abrasives work at the largest grit size in their formulation, the Tormek honing compound is honing at about 8,000 grit.
It's interesting that even at 3 microns, under a 200X microscope, scratching, albeit very small, is still apparent. Practically, for our purposes, that's pretty meaningless, but I find it interesting nonetheless. I'm getting a much better understanding of how abrasive coarseness effects steel.
Mark
Particularly interesting about Tormek compound is that it contains nearly equal parts 1, 2, and 3 micron abrasive. When the 3 micron particles break down, the 2 micron particles take over, and when the 2 micron particles break down, the 1 micron particles take over. If you experiment with different compounds (I have...quite a bit) you'll find other compounds that will leave a surface as polished as Tormek compound, and you'll find some that cut as fast as Tormek compound, but you won't find the combination of fast cut and fine finish.
Test post
Well, isn't that just the coolest thing!
I've noticed that when you first apply compound that it fees more "cutty", i.e., more resistance. Then after honing for awhile, it's much smoother. I had never really considered that what was actually happening was abrasive particulate breakdown. I thought it was just getting worn away as it seems to end up on the bench.
Nor had I considered that could actually be advantageous. Cutting to polishing in one squirt of compound!
My, you are a veritable cornucopia of useful information Jeff. :) Thanks.
Are we reading the same article????
The conclusion of this "very objective and scientific approach" is that the experimenter REFUTES stropping as a useful technique after sharpening. He says it changes both the edge geometry and the steel integrity. Here's a quote from his conclusion
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The second case often cited is stropping of a freshly honed tool. That is, as the last step of sharpening people strop the tool. If you use the abrasives and the jig I do, honing produces exactly the edge profile you want and steel condition you want. Further abrasion, particularly freehand abrasion, can only begin the wear process! You would notice no benefit. In fact, you would notice reduced edge sharpness and durability.
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He goes on to discuss any opinion to the contrary (since his tests prove otherwise) is either "magic thinking" or an accidental improvement in sharpness due to correcting poor original grinding (which he calls honing). So boys, either I'm misreading this or Mr scientist is rejecting stropping of plane blades and chisels??
And incidentally, I might be misreading it cos I'm in the emergency room of hospital doing this on an iPhone!!
Here's a quote of his final conclusion:
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Conclusions
What conclusions should you draw from these tests?
If you are using 3M microfinishing abrasives you should not strop using any of these compounds on a maple board.
If you are using some other abrasive or blade holding method, and if stropping is improving the sharpness of your blades, then your previous honing step is producing a bad profile. You should investigate other honing techniques - in particular, the techniques discussed in these pages.
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He's trying to demystify stropping isn't he?
I agree Rob. I found it confusing too. The key to understanding what he is sayilng is:
"...in all cases stropping left a worse edge than I was getting after the 0.5 micron 3M abrasive sheet.
So, he's honing to something like 30K-60K grit, with 3M Micron abrasive film, and then comparing that to stropping with compound.
Like I mentioned, "Practically, for our purposes, that's pretty meaningless, but I find it interesting nonetheless."
It does howver give some perspective on exactly what is happing when you strop with compound, and how that compares to fine abrasives.
BTW, hope everything goes well! Sitting in the ER ain't no fun!
Last test at 10:30 tonight. If all well I go home. Chest pain this morning while cutting cherry bowl blanks from a tree I was given yesterday
Personally I think it's a fuss over nothing. Been here all blinking day while my blanks need waxing!!
Bored bored bored!!
Here's some more stuff you can read whilst being bored!
http://www3.telus.net/BrentBeach/Sharpen/sitemap.html
He's into planer blades. I'll bet the blades he sharpens are the sharpest you would ever use.
He hand sharpens at 15,5,0.5 micron abrasives on glass.
A lot of interesting info on his site. Might help reduce bordom for an hour or two. :)
Cheers old son :-)
Blimey......and I thought we (on this forum) were anal about sharpening. This guys in the stratosphere!!
Thanks for posting the article, grepper. I printed it out and found it interesting. I believe the author is heading in the right direction, although I would not consider the article definitive.
I liked the idea of using the jig for consistency.
I was less impressed that he used several types of blades to test the different compounds. He probably did not want to end up with an unusably short blade at the end. I understand this. However, adding blade variables does not help substantiate the research.
I know nothing about the author's background or credentials. I use both terms because someone like our own Jeff, while he might not have a PhD in forestry from Yale, does have a very extensive amount of field experience. I appreciate both the academic rigor of Dr. R Bruce Hoadley (author of Understanding Wood) and the "in the trenches" experience Jeff has developed over the years. We need both.
I would be curious to know how fine diamond paste would compare. I would also like to know more about the effect of using 90 grit valve grinding compound.
What about the effect of abrasives breaking down with use into finer grits?
Jeff exaggerates the effect of the Tormek compound. The US Forestry Service, after a multimillion dollar ten year study, that the use of the Tormek compound and leather wheel was only 94.327% as effective as an 8000 grit flat water stone. (Just kidding, Jeff.....) Seriously, I think Jeff's comment deserves some serious consideration. Any process which can offer results so close to a longer process in a fraction of the time warrants thought. In the machine trades, operations are not done for perfection ("dead nuts" perfect). Well established standards of tolerance for different applications are used. While 95% at one fifth the labor cost might not suffice for the most rigorous laboratory standards, it would probably exceed the requirements for almost all other work.
One question, Jeff: How long would you guess it took you to reach a level of high proficiency with the leather honing wheel?
Thanks,
Ken
While I had a particularly high motivation (staying in business) in the first days of my Tormek experience, I would say that within 20 or 30 tools I felt pretty confident that I could make the honing wheel do anything I wanted it to do.
I also had two excellent instructors in Geoff Brown and Torgny Jansson.
One point made in the Beach article that nobody has mentioned here was that while a finer paste like Tormek's does a better job, it also takes a lot longer to do it. That makes me wonder if those having honing problems with the Tormek wheel aren't just having problems with technique, but maybe they are not using enough time to get the job done properly. I saw a sharpening video today where the guy said he has switched from Tormek's paste to Lee Valley's green crayon. It seems obvious to me after having read the article that he did that because he gets a faster (if not as good) result from the green stuff, and he probably has to do it more often too.
Jeff, your answer gave me a good laugh. Isn't it amazing what a great motivator staying afloat can be! In addition to the laugh, your answer also has the ring of truth from experience.
By the way, I would rank studying with Torgny Jansson as more useful than the PhD from Yale in the Tormek field. I don't recognize the name Geoff Brown. Please help fill this gap in my knowledge.
Mike, you make a good point about speed. In a really busy sharpening session I might have as many as three chisels to sharpen and maybe a plane or two. I can't spend all day!!! :)
Ken
If you polish a surface with 0.5 µm grit, then it's not going to get smoother by applying a 1, 2, or 3 µm grit honing compound.
If, on the other hand, you are trying to put a tooth on an edge, you do want the scratches.
That's what I take from that article and this discussion.
So, for example, on a plane iron you may want that smooth edge so you wouldn't hone after polishing with 0.5 µm grit. But on a kitchen knife you may want that tooth on your edge to help you slice through those ripe tomatoes, so in that case honing may be advisable. (But in that case polishing to 0.5 µm is a waste of time, effort, and resources.
I think it all depends on your standards. For most of us, I would venture to say that the Tormek system is a good compromise between getting that perfect polished edge and being able to quickly sharpen a tool and get back to work.
For example, I can spend a while getting a razor sharp edge on a pocket knife. It'll shave hair even though I won't be using it to shave. And after it's been in my pocket a few days and I've used to open packages or sharpen a pencil, it no lnger has that razor sharp edge. And it doesn't need it!
Quote from: Ken S on July 13, 2013, 03:58:51 AM... I don't recognize the name Geoff Brown. Please help fill this gap in my knowledge....
Ken
Geoff Brown owned the UK company which distributed Tormek for many, many years. He also represented Tormek as sales manager for the English speaking world. He still has some capacity with them, though I'm not sure what his official title is now. He was the person who first approached me about selling Tormek in 1992.
Interesting. Thanks, Jeff.
Through all the discussion of honing compounds, the concept of the particles breaking down is mentioned, but doesn't seem to have received the attention I believe it should have.
If we start with larger particles, presumably, they will cut more rapidly at first. This would leave larger scratches if the process was halted prematurely. However, as the particles break down, the scratch pattern should become more refined, just as using progressively finer stones.
I was looking for evidence to document this and found a good source: "Dursol is the original metal polish formula of the company by the same name, nearly unchanged for decades. It has slightly coarser abrasives than PA-70, but also contains a blend of sizes (just like PA-70), so that as the coarse grains break down, the smaller grains take over." (source, Jeff's blog on the sharptoolsusa website)
My original tube of Tormek compound is almost gone. I will reserve my opinion until I have gone through another tube or two. With diligent technique, by that time I should have eliminated operator error as a variable.
Ken
At 40X magnification you can see that the scratch pattern left by the grindstone remains after honing. Honing polishes the flat spots between the scratches and creates that "mirror finish".
A good observation Herman. It seems that the stropping produces a mirror finish just at the very tip. I was skeptical about the finish left by the stone wheel after seeing the scratched surface on the bevels, but the stropping did produce the fine cutting results I was hoping for if not the totally obvious mirror finish. One thing I am still a little in doubt about is the grit of the stone right out of the Tormek box. I assume it is 1,000 grit judging from the results I got, but I'm not 100% certain. I haven't graded the stone to 220 yet as my hand sharpened bevels didn't need it before using the Tormek.
Mike,
The stone is made from 220 grit grains. The 1000 grit finish is an artificial surface produced by abrading the stone with the smooth side of the stone grader.
What isn't often explained is that there is a significant difference between a 220 grit surface that is loaded with dross and not cutting efficiently and a graded 1000 grit finish.
A stone that isn't cleaned with the grader won't remove a lot of material, similar to the graded surface, but what scratches it makes will be irregular (on a microscopic level). The 1000 grit graded finish is uniform in grain size and sharp, so it cuts the steel, rather than just rubbing it.
Bottom line is, I rarely if ever start sharpening something without using one side of the grader or the other. I want to condition the stone to do what I want it to do.
Even on chisels that are in relatively good shape, I spend a few moments using the 220 grit. This establishes a complete bevel at the jig setting. Then when I grade the stone to 1000, the fit between the grindstone and the tool is absolutely precise.
That means that the second step will take less than a minute, and then it's off to the honing wheel to produce a mirror finish on both sides of the chisel.
Thank much for those good tips Jeff.
These are interesting posts. I have been a member of this forum since mid 2009, and probably read the new posts as much an anyone. While it is true that many of the questions posted seem to be repeated with each new crop of members (That's not a bad thing, keep posting!), recent posts seem to be adding a lot of valuable information.
I believe the leather honing wheel is one of the most underutilized and misunderstood parts of the Tormek. These posts are narrowing that knowledge gap.
I don't remember reading about shaping a radius on the inside of the wheel. That's clever! Jeff, is this a recent idea or long established? I would be interested in learning more about how the idea originated. Also, how much of a radius?
Herman, you have probably been on this forum for a long time. Do you remember some of this information being discussed before?
Let's all keep up the good work!
Ken
Jeff has posted the side of the wheel trick before....and since Christmas too because I remembered it when he posted it again just recently.
Ken,
I've done that for many, many years. I don't have a specific radius that I use, just "enough". It starts interfering with straight edges if you get carried away.
Jeff,
Good tip. I will add it to my mental Tormek book.
Ken
Ken, I don't remember ever reading about that rounding-over the edge of the grindstone trick.
Apparently it was posted as others remember it. But I don't. Probably because I didn't think I'd ever have a need for it.
But it's a tip I'll keep in mind now, as I can see how it could be useful.
Participation in this forum has led to wonderful changes in the way I think about the sharpening of steel edges.
Participation in this forum has changed my view of what the tormek's capable of from a sort of good at what it does but limited tool to a veritable cornucopia of grinding possibilities.
What I really like about groups of people working together is how they always push the boundaries of the rules about things through their inventiveness, creating new opportunities and solving problems that were thought too difficult. It's like an "engineering and sharpening and woodworking support group". Very satisfying. I value the frank and open exchange of views, the arguments, the differences of opinions. All go into the melting pot of discussion that sheds light on tricky situations.
Totally agree Rob.
I tell you something else about this forum. Its a proper community because its not so big you don't get to know people a little.
On another massive wood workers forum I joined recently...everyones faceless. This is more a "village". I live in a village and the sense of community is really comparable.
I like the small community idea, although I would welcome participation by more of the 2000 members.
Ken
Small is beautiful :-)
This topic is too informative to fade into oblivion.
Ken