Tormek Community Forum

A jig was used, set at a twenty degree angle in order to insure consistency. The edge images are approximately 200X.

I designed version two of the beautiful knife rest that I built for the Tormek, and stuck it on a belt grinder.  I then sharpened using the following abrasive belts.  In order:

150 grit   aluminum oxide
400 grit 3M Trizact "Gator" aluminum oxide
800 grit silicon carbide
1200 grit (9 micron) 3M Microfinishing Film
Smooth side of leather stropping belt using Tormek honing compound

With each abrasive I attempted to get the blade as sharp as possible.

Here's a picture of version 1 prototype beautiful knife guide and version two stuck on the belt grider:

Version 1 beautiful knife guide:

(http://content.screencast.com/users/bllllllorg/folders/Default/media/4fce947a-77e4-4fc0-9b0b-0ccb91a9ccc9/00Version1.png)

Version 2 knife guide stuck on a belt grinder:

(http://content.screencast.com/users/bllllllorg/folders/Default/media/54d1fb96-12de-4846-a431-09b42356dd5f/0Grinder1.png)

(http://content.screencast.com/users/bllllllorg/folders/Default/media/2df533ae-c5bd-4601-8fb9-bf68557cf622/0Grinder2.png)

Here is the knife.  It's an Oneida that I subject to all sorts of torture.  So please no complaining about the edge profile.  :)  Note the blue line. This marks the area we will be viewing in all the following images. 

(http://content.screencast.com/users/bllllllorg/folders/Default/media/105d3c52-64e4-4bdf-8f81-9dc86a91f428/00Knife.png)


Here's the edge through the succession of abrasives:

150 grit:  This basically destroyed the edge.  I could not get it sharp.  Touching the belt formed an immediate burr on the opposing side. Further attempts just ground away metal.  If lightly honed at this point, it would basically be a saw:

(http://content.screencast.com/users/bllllllorg/folders/Default/media/1719f43e-cfc3-474a-963a-015ecb008180/0grit1%20150.png)

400 grit:  Getting a little sharper.  Barely hangs on nail.  Saws well through paper.  If lightly honed at this point it would be useable for any type of situation where a very toothy, aggressive edge would be useful.

(http://content.screencast.com/users/bllllllorg/folders/Default/media/536dbab8-9b43-49a0-970c-f9275d0a4fda/0grit2%20400.png)

800 grit:  Getting very sharp.  Still a little toothy.  Chop cuts paper pretty well, but somewhat grabby.  Slices paper nicely.  Honed now would be very generally useful.  Nice edge.

(http://content.screencast.com/users/bllllllorg/folders/Default/media/26b70f22-3e7a-4c6d-896b-2d45a6f60b98/0grit3%20800.png)

1200 grit:  It's very sharp.  Chop cuts paper, hangs well on nail.  A very useable edge.  Still some tooth, but very sharp.  Accidentally bumping against your hand and you will bleed.  The next step is honing.

(http://content.screencast.com/users/bllllllorg/folders/Default/media/4f4c7094-07ea-4415-8e2e-09828628f7aa/0grit4%201200.png)

Honed using Tormek honing compound:  It is extremely, flesh slicing sharp.  When handling this knife it demands the respect due when handling a scapel.  Chop cuts and melts through paper.  Be careful around fingernails.  It is extremely sharp and rather dangerous. 

This is an interesting edge.  The image doesn't due justice to the mirror finish.  It would be great for a cleaver, or probably woodworking tools, or if you wanted to cut non sinuous flesh. .  While very sharp, it suffers limitations in normal use.   I've used knives like this on overly ripe tomatoes with tough skin, and oddly, even though they are razor sharp, they just ride on the surface and smash the tomato.  You need to first break the surface of the skin and then they melt through the tomato like butter.  For an everyday kitchen knife, I'd knock it back down to 800 or 1200 grit to give it just a little bite.

(http://content.screencast.com/users/bllllllorg/folders/Default/media/b94190ff-6f2f-4d32-bc40-dc6f6f7c927d/0grit5%20honed.png)

The next version the knife rest I plan to fabricate completely of metal and use a 180 degree articulating ball camera mount head from a tripod for easy, infinitely adjustable rest positioning.

One interesting thing about the knife rest:  It's easier and faster to just do it freehand, and freehanding achieves just as fine of an edge.  A rest is necessary however, at least for me, if the requirement is to match an existing bevel angle.

Hope everybody finds this as interesting as I did  :)

Nice documentation, Mark.  What's the bevel angle?

The block o' wood is cut to 20 degrees.  But as I remember from your jig, there is more to knowing the angle than just the angle of the rest.  Seems like you added in the angel of the blade itself?  You have understood more detail on that than I have, but at any rate, the block o' wood jig/rest/guide thing is chopped at 20 degrees.

very nice work.  What still confuses me is that your tests and also that study Jeff posted completely refute the data supplied by the Canadian article?? You're now back with the traditional Tormek assumption that honing just works and gets you a sharper edge (as long as it's finely and well sharpened in the first place).

He was saying it degraded the steel...it risked giving a multi faceted edge etc.....its becoming like bloomin doctors and cures for things....you don't know who to believe in the end there are so many competing theories!

In the article by Brent Beach, he was sharping to 0.5 micron which is like 60,000 grit.  The Tormek compound, according to Jeff, contains equal amounts of 1,2, and 3 micron abrasives. Most other crayons and compounds are coarser than that.

So, if you start with 0.5 micron in the first place, honing with anything more course is going to degrade the edge.

The thing that makes the Beach article confusing is that it's easy to miss the fact that his edge was so finely sharpened to begin with.

I went from 1200 (15 micron) grit and then honed with the Tormek (8,000 - 14,000 grit) compound, so obviously it further smoothed the edge.

right...so he's only arguing stropping makes an edge worse when the grit size of the paste abrasive is actually larger than that used in the original sharpening?  Cos I must say, I didn't get that....that's kind of obvious right? What I got from it was that the stropping process affects the stability of the steel edge somehow?? 

Well, Rob, I think you summed it up nicely.  You saideth, "so he's only arguing stropping makes an edge worse when the grit size of the paste abrasive is actually larger than that used in the original sharpening?...that's kind of obvious right?"

Looked at from that perspective it does sound rather, umm... duh. :) LOL.

I guess he was just out to prove that different honing compounds are really not as fine as 3M .05 film film.

Nonetheless, I did come out of it with a better understanding of how micro abrasives and honing compounds effect steel.

I think that what's also being said is that honing is not as good as grinding, when you're at that scale of a very small abrasive particle.

So, yes, it would probably be better if you polished the edge on a water stone after sharpening with a Tormek, but the honing with the leather wheel is faster.

Reminds me of the NASA director's incentive to make space travel faster, better, and cheaper.  After he was given his chance to succeed we found out that you can have any two of those three things, but only at the expensive of the third.

So in this case you can get a better edge with a 0.5 micrometer abrasive.  And it'll be cheaper.  But it won't be faster.

Right....I think that's sunk in now....so with respect to the Tormek then, with a regular wheel.  We grind to 1000 grit and get a pretty fine edge.  According to the logic we've just discussed, do we not then jump straight from 1000 grit to a very fine paste grit size?  I forget what grit size wheel equates to what Micron particle size in the paste (Herman documented it recently), but do we not fall directly into Herman's NASA analogy whereby the gap between a 1000 grit graded stone and the paste particle size (in the off the shelf Tormek paste) is too wide? At least wide enough to require a long time to really get a fine edge?

I appreciate this is theoretical because for pretty much everything I do, after 1000 grit and de-burring on the strop, my tools are easily sharp enough for practical purposes. This is for me about really understanding whats happening at the strop because as recorded earlier, try as I do, with the recommended techniques, I still get mixed results with the strop.  It's very tempting (I know) to simply chalk that off to poor technique, but I've been doing it for a long time now, it's not like I'm an unconscious incompetent, quite the contrary, I'm acutely aware of every nuance of the stropping procedure and believe I'm conscious competent.

This thread is very useful in understanding the process at the very edge.  My goal here is to have 100% confidence in the approach being taken so it will consistently yield, predictable results.

Straw poll in the interest of academic research....who here has reached that (apart from Jeff of course)?

Who here, including the veterans, can HONESTLY say that after stropping they are 100% confident the edge is sharper than it was after sharpening every single time, no matter what the tool?

I don't have enough experience with my Tormek to express an opinion about rehoming, but after sharpening my first plane iron to 1,000 grit on the stone wheel. I tried it out a little before honing just so I could see the difference . After honing it had an excellent edge. This is a Stanley/Bailey iron in my S/B #4. I've been using it this morning to smooth some construction fir (Norwegian Spruce) that I'm using to make some new tool holders. I've planed 4meters in length in total  which are now smooth as silk in spite of the hard little knots, all without any chatter. I avoided the one large knot on the 3 boards which was resawn from a 2X4 as it will be eliminated. I am very pleased with how well the edge is standing up. When finished I could not feel any difference in the quality of the cut or the beautiful gossamer shavings I got. I guess I will try honing it when it gets dull to see if that alone will restore the edge, and if so, how long it will last compared to the initial sharpening.

One thing that I got from the Beach article is that I don't like the term "honing". I think it just confuses what sharpening is.

Folks seem to use the term honing when using an abrasive not fixed to a surface as when using a "honing" paste or crayon stick.  Either way, it's just applying a steel cutting abrasive to some sort of surface and sharpening.  But as long as it cuts steel this is still just sharpening, the only difference being that it is using finer abrasive on a soft surface.

As far as I understand it, stropping is different from sharpening.  Stropping uses a surface, such as leather, that is to soft to cut steel and actually further sharpen the edge, but it could still straighten a slightly bent edge, thereby conditioning the edge.  However, just to confuse things, "honing" compound can be applied to a leather strop.   Maybe that should be called stoppening.

As long as steel is being removed with a finer abrasive than was previously used, the bevel should still get smoother and the edge thickness reduced.  In other words, it should become sharper.

It is however fairly easy to dull an edge using the stropping wheel.  Why?  Because if you don't use a jig, it would be very easy to apply the edge being sharpened at a greater angle than the edge was previously sharpened to, thereby rounding the edge.  I suppose that because the leather on the wheel is soft, if you pressed hard enough the leather could actually wrap around the edge, thereby increasing the angle and dulling it, but I find that is probably not as likely.

Maybe "honing"  just means refining a sharpened edge.  But then where does sharpening change to honing?  1000 grit, 2,000 grit or maybe 12,000 grit? 

I think I'll just stick with sharpening and stropping.  Stropping with or without compound.  If using a steel cutting compound, it's still sharpening, but just using a strop as the substrate to hold the compound.

You right right Mark. Stropping is what the leather wheel really does. With respect to the Tormek I have been describing work with the stone wheel as sharpening and honing as work for the leather wheel just for discussion purposes, but in fact the definition of honing is to refine a ground metal surface .Any kind of sharpening beyond rough grinding could be called honing. So I will call the leather wheel work stropping from now on.

Its actually very confusing because throughout this forum the term "honing" is generally accepted to mean stropping with the leather wheel :-)

Great pics and very interesting but what has this got to do with the Tormek as it only has two grits plus the honing wheel?

you would need to read through the whole series of threads on stropping and abrasive particle sizes to appreciate the entire debate.

Quote from: jeffs55 on July 16, 2013, 05:45:51 AM
Great pics and very interesting but what has this got to do with the Tormek as it only has two grits plus the honing wheel?

With the advent of the Japanese Waterstone that's no longer the case.  Plus, just because we've got the Tormek doesn't mean we can't use other sharpening tools.

My take on all this is that the Tormek leather wheel is good for removing the burr.  It will not polish the bevel properly after grinding with the 1000 grit grindstone because the abrasive used in leather wheel honing is of too small a grit.

you mentioned before that the shine derived from a honed tool is coming from the valleys in the scratch pattern rather than the ridges right? (I'm recalling a post you did where you examined it under a microscope I seem to remember)

So that means the grit in the honing compound is being squashed into the valleys by the soft leather substrate?  And that the grit is too fine to abrade off the peaks of the scratch pattern?  Again, just trying to confirm my understanding

Nobody has responded to the question I posted recently:

Can forum members report their honest feedback on results after honing on the leather wheel?  I am genuinely interested to know if any of you are achieving 100% consistently repeatable success when honing on the leather strop.  By that I mean that the tool is sharper after honing than it was straight off the grinder at 1000 grit.

And by sharp I mean Jeff's paper cutting style sharp...you know...really sharp.

I still bang on about this because I'm not getting 100% success, I'm getting some, but its inconsistent and I just know its not poor honing technique because I'm too careful for that to be a variable. I certainly get polished ie shiny steel but its not necessarily sharper than straight off the grinder.

I am really interested to learn (and therefore explore why) what people are experiencing.

My very limited experience is probably not particularly valid Rob, but as I mentioned in an earlier post, I used my one Tormek sharpened and stropped chisel one whole day on soft wood. I did a lot of work with it. At the end of the day the chisel still felt very sharp and it passed the fingernail test. ThenI did the paper test. It didn't cut, just tore the paper. I took it directly to the stropping wheel for about 30-40 seconds and did the paper test again. This time it passed the test, cutting as well as after my original sharpening session. Now a disclaimer; the chisel in question is a very cheap one purchased 17 years ago as part of a set of four for the equivalent of about 5 pounds. The steel might be pretty soft and therefore easier to strop than a better quality chisel.

you see that's fascinating Mike because I'm experiencing that too.  I find I can "wake up" a dull chisel with the strop as long as its not too far gone. And yet once Ive got the burr removed from sharpening, I don't like to mess further or it often seems to get less sharp. (It tears rather than slices paper).

I'm in the same place as Rob. Although I haven't done any defined tests, I am sure that when I hone the bevel I am sure it is not as sharp as straight off the fine graded wheel. Yes super shiney and very smooth, but........

I don't have enough needing re-sharpened at the moment where I could do something quantitive, but there are some which will need re-sharpening soon, so I will do some with and without honing and see if I can get something definitive.

General comments from what I'm reading here....

I think en masse you guys are doing a tiny bit of rounding over of the edge. I get that impression from the comments about the tool not being as sharp after honing as before. That's not possible unless you're bringing one angle or the other too steep into the leather, and I'll wager that it's the backside where you're doing it.

Kiss the edge.

The other area to watch to really get the most out of the honing wheel is the step immediately before the honing wheel. The better the surface finish of the final cut off the stone, the easier it is for the honing wheel to deliver a mirror polish quickly. I wholeheartedly disagree with Herman's comment a few posts ago that the honing compound is too fine to polish the bevel properly. If you're not getting a mirror polish in just a few moments on the leather, your stone surface wasn't properly graded to the fine cut. If you're getting "polished grooves"...the step you blundered wasn't on the honing wheel, it was the last step on the grindstone.

This gets back to a reply I wrote to Mike a day or two ago. I think the true key to Tormek success is learning to make the grindstone do what you want it to do with the stone grader.

I will say one thing about that last step on the wheel that I notice. Once you've graded to 1000 and fine tuned at that grit...just like at 220 you can hear and feel when the stone has sort of "worn off" the sharpest of the abrasive particles that were sticking out of the surface.

The stone is probably not really "cutting" as such now, more burnishing, a sort of rubbing I guess.  But I swear that if you do a few more passes when its like this AND with very light finger pressure, its almost like you've gone up another step in grit fineness.  That technique also seems to give a really sharp bevel straight off the wheel. (There is also a lot less burr)  It even looks a bit more polished too though nothing like after stropping.  I guess you're saying take that very fine surface direct to the strop and do it there.  I think next time I will try jigging the tool with the strop.  That should eliminate operator error as regards rounding over (but having to do that faffing really goes against the grain for me personally). It's funny...I have no objection to jigging the tool for the grinder...and yet I'm all "Mr Complaining" when I have to jig it again for the strop!

Perhaps the solution is for me to go into therapy :-)

Okay, we're really getting into nuance here, but then the devil is in the details.

A dull clogged stone will burnish. A correctly graded stone cuts, but cuts with very fine surface finish. I agree that diminishing pressure on the graded stone is productive.

I'm always surprised when I use a jig when honing. I don't do it as a general rule. In my demonstrating days I wanted it to look easy, and I wanted to teach people how to feel their edge on the wheel. On those occasions when I have used a jig with the honing wheel, I find I get to a mirror finish faster.

That said, my biggest objection to using a jig is that I go back and forth from the back side to the bevel side several times while honing. Maybe as many as 5 or 6. The jig is completely in the way on the back side.

What I see with the 40X microscope is not polished valleys or polished grooves.  I'm getting a polished surface with scratches in it.

When I finish grinding at 1000 grit I see the scratches that are left in the surface of the steel.  Honing polishes the flat spots between the scratches giving me the mirror finish.

I will experiment with making sure the grindstone is properly graded to 1000 grit and try honing with a jig.

It's a big step between the 1000 grit stone and the honing compound.

I believe we are trying to accomplish two distinct sharpening operations with one method.

Jeff has noted that using the leather honing wheel with the tool in the jig seems to polish the bevel more quickly.  I believe this is correct, and probably a very efficient method to accomplish this.  Polishing the bevel involves smoothing away the small scratches left by the stone when properly graded fine.  It also involves eliminating the burr.

With the back, no such scratches should exist.  If the back has been properly flattened and polished, it should be mirror smooth.  Only the small burr left over from the finely graded wheel should need to be removed.  I believe this is most efficiently accomplished on a flat surface.  Whereas a slight rounding on the bevel side may in fact function as a micro bevel, any such rounding in the back of a chisel acts as a sharpening defect.

I believe the simplistic way to make these sharpening issues compatable is to leave the tool in the jig and buff the bevel.  For the back, tape a piece of cereal box cardboard to a flat surface like thick glass or granite.  Squeeze some Tormek compound on the cardboard.  After buffing the bevel, remove the jig from the USB.  Leave the tool in the jig and strop the back on the cardboard.  Go back and forth between the USB and wheel for the bevel and just the tool in the jig for the back.

I have seen using a ceramic stone suggested for this.  This could be done with my idea, but it would involve cleaning the tool for each cycle.  Using the cardboard with compound eliminates this extra step.

Clues for this came from Rob mentioning that he left his roughing gouge in the Tormek jig for fast touch ups.  From Jeff for mentioning the quicker polish when demoing by honing with the tool in the jig and again from. Jeff for suggesting the problem may be slight rollover on the back side.  Using flat cardboard on the back would eliminate this rollover.  Also noted is Leonard Lee mentioning using cardboard in his sharpening book.

This is an interesting discussion.  Let's continue to pursue it.

Ken

well I like that for an idea Ken.  If Jeff's contention that rolling from the back is more probable than the bevel side then your method should eliminate that.  Why couldn't you just do the stropping of the back on an old fashioned oil stone come to think of it (the fine side).  Then as you say rotate back to the leather strop with the bevel still jigged.

I'll try that and your method see of it gets the mad sharp we're all on about.

Or, I guess you could flatten on the side of the wheel?  Ah no...that's 220 grit isn't it....you cant grade that to 1000 can you Jeff?  I think this has come up before..cant remember.

My problem with working the backside on a flat surface is time. The honing wheel will remove the burr and mirror polish the back (more than it already was) in a few seconds. Doing that on anything flat is going to take longer. You're also right there -- already working on the machine...why set something else up?

If you're rounding over the backside of your tools you don't need another set up, you need to learn how to use your honing wheel.

Sorry if that sounds blunt, but the point of this forum is to teach people how to do things on a Tormek. If there was a serious issue of causing backside problems on the honing wheel, I would be the first to admit it and suggest alternatives. Heck, I don't even work for Tormek any longer. I'm here because I believe in the product.

In 1982 I went to work for Don Peschke at his relatively new magazine, Woodsmith. That's where I learned what sharp is. We used to have competitions to see who could get the best edge the fastest. The art director won consistently, but I was always in the running. Woodsmith stressed (and still does to my knowledge) backside flatness. I believe in it. I embrace it, I practice it, but I will not be convinced that I will destroy my flatness by using the Tormek honing wheel to deburr and polish. If I've shaped the back properly (usually on the side of the wheel, and btw, yes you can grade the side), the honing wheel just doesn't cut enough to alter the shape, only the surface finish.

Interesting discussion and ideas Ken. I think I will try removing the the burr on the back with my 1200 grit diamond plate with a little water. One advantage with the diamond plate is that it is very flat and stays that way. I can't see it ruining the polished edge on the back as it only takes a very light pressure to remove the burr. If that doesn't work I will try the diamond paste on cardboard.

Good comments, Jeff. Your bluntness will help my sharpness get sharper.

Ken

In spite of what I said in my last post, I will be more than happy if I can do the whole job on the Tormek.  My only sharpened chisel so far sure performed much better than I even hoped it would. I will just have to get more experience to find out.

Quote from: mike40 on July 24, 2013, 05:38:27 PM
Interesting discussion and ideas Ken. I think I will try removing the the burr on the back with my 1200 grit diamond plate with a little water. One advantage with the diamond plate is that it is very flat and stays that way. I can't see it ruining the polished edge on the back as it only takes a very light pressure to remove the burr. If that doesn't work I will try the diamond paste on cardboard.

Here's the flaw with this approach, Mike. An edge is only as good as the surface finish on both sides of the bevel. A mirror polish on the front that meets a 1200 grit surface on the back is going to have 1200 grit "grooves" in the cutting edge. If you're not putting scratches in the surface of the back on your diamond stone, either your tool isn't flat or you're not holding it flat, and then you're definitely worse off than doing it on the wheel.

I know I've mentioned this before, but there are so many threads, and this one is really good, so I don't mind repeating myself.

Hold the back side of the tool at 9 o'clock on the honing wheel, about half an inch from the edge. Stand just above and stare straight down into the gap between the tool and the wheel. Pull the tool down slowly until the exact point where the gap disappears. STOP! Push it back up to the half inch point and repeat. Do it 4 or 5 times. Job Done.

Quote from: Jeff Farris on July 24, 2013, 05:36:43 PM
My problem with working the backside on a flat surface is time. The honing wheel will remove the burr and mirror polish the back (more than it already was) in a few seconds. Doing that on anything flat is going to take longer. You're also right there -- already working on the machine...why set something else up?

If you're rounding over the backside of your tools you don't need another set up, you need to learn how to use your honing wheel.

Sorry if that sounds blunt, but the point of this forum is to teach people how to do things on a Tormek. If there was a serious issue of causing backside problems on the honing wheel, I would be the first to admit it and suggest alternatives. Heck, I don't even work for Tormek any longer. I'm here because I believe in the product.

In 1982 I went to work for Don Peschke at his relatively new magazine, Woodsmith. That's where I learned what sharp is. We used to have competitions to see who could get the best edge the fastest. The art director won consistently, but I was always in the running. Woodsmith stressed (and still does to my knowledge) backside flatness. I believe in it. I embrace it, I practice it, but I will not be convinced that I will destroy my flatness by using the Tormek honing wheel to deburr and polish. If I've shaped the back properly (usually on the side of the wheel, and btw, yes you can grade the side), the honing wheel just doesn't cut enough to alter the shape, only the surface finish.

I think everyones with you Jeff....no one wants to introduce an alternative step IF the desired edge can be achieved right there on the Tormek.  You know me...I hate the faff of changing setups, jigs etc.  But your bluntness brilliantly nails it.....is operator error causing this rounding over? I think I'm struggling to believe its the case with me given how hard I've worked to learn this procedure but I also must say....you do sound right :-)  And its certainly the most plausible explanation.  Dam...where are those chisels :-)

I'm not real big on stats, but I think our relatively new member Mike wins for the "fastest to 100 posts". Thanks for diving in, Mike.

yay....well done Mike :-)

Now we all have our idiosyncrasies about how we sharpen and hone, but there is a subjective part at the end -


I have already commented that I believe that after honing my chisel edges are not as sharp as coming off a fine graded wheel. I have flattened the backs of my chisels using the side of the wheel, waterstones of various grades and polished up using the leather wheel. Ergo I believe that I should not need to re-address the backs for a while.

I then do the bevel side. Some I do as a single bevel at 25 degrees and hone up at that for paring use. Some I put a secondary bevel at 30 degrees using a fin graded wheel and then hone on the leather. I use the SE-76 jig for all operations on the bevel - I don't free hand the honing. (It's a bit a drag re-setting the usb for the stone or leather wheel, but better than what my free hand would achieve.) So I am not rounding from the back as I haven't touched it.

So how do I (or indeed anyone else) prove they are sharper by one method or another?

There is the paper cutting demo - which depends on the paper used, the angle of attack; and a matter of feel for the result.

Some years ago, I was in a test house in the USA, and one contract they had was to test samples of face shields used on fighter pilots' helmets to ensure they were meeting the desired impact standard. The test jig used a hardened pointed object (like a sharpened nail) with a specific mass attached, dropped from specific height on to the visor shield. They measured the depth of penetration for the quantitive result.

Now I do not propose dropping one of my sharpened chisels and see the penetration into my foot or other object!!!!!
I have enough inadvertent excursions without trying to formalise this one!

Anyone have any suggestions for a quantitative method of testing?

Robin,

Your method ignores what I feel is the most important step in producing a really keen edge.

The work you do on the bevel is going to raise a burr on the back of the chisel. You have to remove that burr from the back side. If you try to take it off from the front, you will undoubtedly round over your edge.

What you've described is perfect, except that you aren't removing the burr after working on the bevel. Given what you've said about how your back is to begin with, I am going to say you're about 30-45 seconds away from what I would consider really sharp. Just hit the back side on the leather as I described a couple posts ago, and Bob's your uncle.

What is sharp?

It will catch your fingernail and not slide.

It will cut any thickness of paper in a controlled way (I used to cut circles out of magazine stock).

Perhaps most relevant: It will cut across end-grain in softwoods without tearing.

Back in the days when prepress work for publications was done with waxed type and artboards, XActo had advertisements in the trade press that suggested you cut along a dotted line in their ad. If you didn't cut at least 3 pages below, you needed a new blade in your XActo. I'm not sure how that's relevant, but anytime the discussion about "how sharp is sharp" comes up, I recall those ads from about 35 years ago.

Thanks Jeff - I am slowly putting aside a few chisels for a sharpening session, so I will report back in due course.

Just a wee distraction about stropping - when I retired from my previous career, I went to college (two years full time; two years part time) for Furniture Restoration.  The cabinet maker showed us how to sharpen chisels on a wet grinder of many years vintage; followed by various grades of waterstones. All by eye and feel - no jigs. The final process was to remove the tiny burr and this was done by (best description coming!) holding the chisel in one hand, and flicking the chisel blade backwards and forwards across the heel of the other hand. (Similar thing if you had say a wet paint brush and you wanted to get the water out of the bristles.)

Now with practice I could get my blades sharp - I spent probably hundreds of hours to get to a standard I with which I was happy. However I now get much better and consistent results with the Tormek even if I still have a burr attached!

Robin, as I said in another post, I tested the stropping effect by using my newly Tormek sharpened/stropped chisel all day. It still passed the fingernail test at the end of the day, but not the paper test. I then stropped it on the Tormek leather wheel only, with some diamond paste. I worked both the bevel and the back. After that it passed the paper test again. That seemed to me to be a full restoration of the edge and proof that the stropping wheel does work. One factor not mentioned in the various posts in this thread is the hardness of the steel being sharpened. Time must also be a factor here and not just technique?

I experience exactly that also.....can bring back a not too far gone chisel or plane edge with the strop.....I'm not even going to ask whats going on there at the microscopic level because in theory that shouldn't work right??

But......it does

I'm going to go out on a limb and say that microscopically, it does work.

As I understand it, two things are happening as an edge dulls...folding and crumbling...both of which are happening on a very minute level. Hitting the strop before the edge deteriorates too far is going to straighten out the folds, and if the crumbles haven't reached the size of the abrasive yet, it should deal with them just as well.

Carvers practice this approach better than any other group I've worked with.

That is very true about carvers Jeff. One of the best carvers in our area who frequently attends demonstration days at our local woodworking store continually strops while carving every few minutes. He doesn't use the strop when chip carving though. Instead he uses his stone to lightly hone very frequently a few very light strokes on his stone, with maybe just a minute or two intervals. If you saw his work you would immediately know that he is always working with very sharp tools.

that's very interesting indeed (both Jeff and Mike).  After that Canadian article which completely contradicts all of this, I have to say I was confused about what was going on.  But I also experience exactly as you describe as mentioned a couple posts ago.  This is "apparently impossible" according to the Canadian chap but clearly that's rubbish!

The very fact that an entire group of woodworkers, namely carvers routinely and successfully use this method just corroborates what Mike and I have actually experienced.  So either I'm missing some technical detail about abrasive size etc or he's got something wrong (I wonder if we could get him to join the forum and elaborate on his thinking....that would be amusing).

Again, stopping with the OCD for 1 second, on a practical level it wouldn't make a jot of difference to what I actually do because as I say, I know it works in the workshop.

I met chip carver, Wayne Barton, years ago at a workshop.  The workshop was two days (a weekend). Unfortunately, I had a back injury Sunday morning, and missed the second day.  It was a good class.

Wayne uses and sold two ceramic sharpening stones.  The more coarse stone was for actual sharpening.  He described the finer stone as "refreshing" the edge.  That sound like what your local carver was doing, Mike.

Incidentally, chip carving is a good choice to add a bit of carving to projects.  The basic techniques are straightforward and Wayne only uses two tools for his work.

Ken

Lucky you Ken to have had a class with Wayne Barton. My son expressed interest in chip carving and I got him a book by Barton. Many chip carvers are using the ceramic stones these days with great success. I have been chip carving on some of my turnings for many years now just to add texture or a little more interest to them. This is a good idea when working with very plain woods without visible grain patterns. Nice on Birch, Linden, Basswood, etc. I can't claim to be highly skilled at chip carving, but it is definitely a good way to go for those who don't carve as their main hobby, but still want to get some enjoyment from it. I think that well done chip carving with the right patterns can be just as decorative as the acanthus style carving.

Another form of carving that can be very nice if well done is similar to scrimshaw work, only in wood instead of bone or horn. The pattern is cut (incised) with just a straight cut, maybe 1/32" in depth. Then bark sanding dust is mixed with oil and worked into the cuts to make the pattern more visible. We have some beautiful examples of such work here in Norway like the spoons below. The technique is called 'Kolrosing' her. The dark backgrounds and shaded areas are usually just a lot of straight cuts closely spaced together. Kolrosing  sounds like an easy technique, but I have found it a lot more difficult than I thought before trying it out. It is however, a lot easier than relief carving, but it requires great concentration and good  control, plus a short stout knife blade with a good handle.

(http://i647.photobucket.com/albums/uu199/mikego/004-2.jpg)

Quote from: Rob on July 26, 2013, 08:15:02 PM
I experience exactly that also.....can bring back a not too far gone chisel or plane edge with the strop.....I'm not even going to ask whats going on there at the microscopic level because in theory that shouldn't work right??

I think it's sort of the same thing as using a steel on a knife.  Theories are based on models, and so are only as good as the model.

The classic example is the traffic engineer and the car mechanic.  The traffic engineer models a car as a moving dot on his map.  No need to be concerned with the details of how the car makes itself move.  Such a model could never be used by the mechanic as he needs very much to be concerned with the details of how the car makes itself move, and stop!

Quote from: Rob on July 27, 2013, 11:01:56 AM
After that Canadian article which completely contradicts all of this, I have to say I was confused about what was going on. 

I guess I've lost track of the conversation here as I can't recall the Canadian article.

But following up on the modelling process, when we're grinding an edge we model the steel as a homogeneous material that needs to be shaped in such a way that two surfaces meet at a line.

When we zoom in on that line we find that it's not really a line at all.  The steel is so thin there that the crystalline structure of the steel is apparent.  That line is not straight but jagged.  And as Jeff points out it folds over and it crumbles. 

When we're grinding the edge we don't care about the crystalline structure of the steel.  We just try to get the geometry right and hope that the metallurgist did his job correctly and provided us with steel of the correct properties to actually form and hold an edge.

You can think of one of these models as being macroscopic and the other microscopic.  The modelling process itself is inherently flawed, but the proof is in the pudding.  If the model is good enough then the engineers who use it will be successful when they design tools with cutting edges and the machines that can sharpen them.

right...I think :-)

How many degrees do you have Herman?

It seems to me Herman that you are implying that theory is indeed theory and not fact. When a theory becomes proven it is then fact and no longer theory. Another problem with theories is that they often don't t take into account all of the variables, and therefore never become fact. In this case the breakdown of larger particles into smaller particles in stropping paste is a variable.  Also as you mention, the steel quality may vary and in my total ignorance of the subject, there might be other variables too, such as time, pressure exerted, water quality in the trough, the condition of the stone and stropping wheel, etc, etc. After reading the Tormek manual and seeing the relative pressure between wide and narrow blades, I would think pressure exerted might be a more important part of the sharpening/stropping equation than one might think. So where does this leave us? My best guess is trial and error with our particular tools instead of quasi scientific analysis.

From Herman's reply:

Quote from: Rob on Yesterday at 10:01:56 am
After that Canadian article which completely contradicts all of this, I have to say I was confused about what was going on.
-----------

Apparently the Canadian article caused some confusion; hopefully this will help clarify what he was actually saying.  Early in the article he states:

"This page is actually concerned with stropping of plane irons after a final honing step using a 0.5 micron abrasive."

He was sharpening, using 0.5 micron 3M Microfinishing Film.  The important thing to notice is that 0.5 micron size.  The Tormek Honing compound is, according to Jeff, comprised of equal parts of 1, 2, and 3 micron abrasives, and most other honing compounds a comprised much coarser abrasives than that.

Even the smallest abrasive in the Tormek Honing Compound is 2X more coarse then what he originally sharpened to.

So, he is only saying, that:  If you sharpen to 0.5 microns, using any of the honing compounds that he tested results in a degradation of the edge.

Is useful to know?  To me, yes.  I now have a much better understanding of exactly what stropping with various grit levels of stropping compounds means. 

Folks talk about how they really like the white crayon, or some like the black compound, etc.  Well, what grit level is it?  What grit level did I sharpen to?  How should a particular honing compound effect the edge? 

I find those questions to be interesting, and it's useful to be able to hazard an educated guess. :)

right...so all we can reasonably conclude is that if you sharpen to a grit size that's smaller than that in your stropping paste.....its a waste of time stropping because your strop is essentially worsening the edge with the less refined grit.

In the case of us and the Tormek, that doesn't hold true because at the 1000 grit graded sharpen, we get an edge that can be significantly enhanced with the 1,2,3 micron stropping paste that comes with the Tormek.

This is why its possible to "bring back" a chisel or plane iron edge like Mike and I have experienced just by stropping.  The proviso is that said edge cannot have blunted much or its not recoverable, presumably because too much folding has occurred for the small micron size to cut it.

Further...many of us, me included have reported mixed results when stropping directly after sharpening ie the recommended method for max sharpness. By mixed I mean the edge seemed less sharp after stropping than it was after sharpening at 1000 grit.

Whilst not a 100% certainty, it is now considered most likely that that result is caused by operator error ie bringing the blade up at too steep an angle and therefore folding the edge.

I can see that it would be tempting to raise the blade too high on the stropping wheel while free handing or maybe applying too much pressure when using the jig, through impatience and the desire to see that mirror shine quickly.

I had already read a lot of comments on this forum about the subject before I tried sharpening/stropping for the first time, so with those comments in mind, I tried to error on the safe side instead of pushing my luck, and I got a really good result. I am now wondering how it will go with my Swedish chrome vanadium chisels which are harder steel than the inexpensive chisel I have  already sharpened. The same applies to my plane irons which are 62 HRC compared to the Stanley plane iron which is probably around 59. I am expecting that I will have to use more time stropping them.

I like reading and learning about the technical aspects of sharpening, but my real concern is how my edges work in actual use and how long the edge lasts before the need for re-stropping or resharpening. Of course that is a rather subjective test, as one man's satisfaction could be another's agony. I can't think of any other quick way to test sharpness than the fingernail, pine end grain and paper tests, but they don't tell you how long the edge stays sharp.

Quote from: grepper on July 28, 2013, 05:44:25 AM
So, he is only saying, that:  If you sharpen to 0.5 microns, using any of the honing compounds that he tested results in a degradation of the edge.

Unless you're trying to add a "tooth" to the edge.

which for those who might think that counter intuitive to a sharp edge....is useful for certain applications, in particular kitchen knives that are destined to cut soft fruit and veg like tomatoes.  The "tooth" assists in cutting through the resistant skin

Hi guys. I'm not too concerned about the kitchen knives. Serrated knives cut the tomatoes pretty good anyway. My wife told me she doesn't want the carving knives super sharp. Of course that won't stop me from making at least one Tormek sharp whenever I will be doing the carving. I just finished doing my first good quality chisel. I'll tell you about my experience with that and a couple of other things with some photos after my camera battery is charged a little later today. I'm sure you will be waiting breathlessly for that post, ha, ha.

Quote from: Rob on July 27, 2013, 08:21:11 PM
How many degrees do you have Herman?

Just enough, Rob.  But not too many.   :)

 8)