What are your next "mad scientist" sharpening experiments?

WOW, another great post HH. I see a whole lot of new ideas to think about, and may give some of this a try. :thumbup:

Your idea of grooving the red oak strops is interesting. I have a small leather-on-oak strop block used with 1 mic diamond paste. Initially, I just applied it to the leather, but had some excess left over, and just flipped the block over and smeared it around on the bare wood side (sanded smooth). Worked very well, and as you said, the compound does polish the wood quite fast. I hadn't considered the longitudinal grooves to change how the compound works, though. I have occasionally used it with edge-leading strokes, but the occasional errant pass has left some cuts in the wood that need to be sanded out again. :)

The compressed paper stropping looks interesting too. Might've just inspired me with yet another way to use the old phonebooks I've got laying around. :D

BTW, I think the .pdf file you linked here was originally posted in posts #10 and #14 (it's in two parts) in this linked thread, by member 'J D Wijbenga' (at least, it's the first I'd seen of it) -->: 1000 Years Ago


David
 
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Yes, that is the member. I read it several times as it was a very good read. Quite historical and factual and piqued my interest toward blade maintenance with little metal removal as I didn't care for leather stropping because of what it did to the edge. So, I tried it on a 2X7" oak board using 220-250 grit with low success. It didn't remove the burr on my 420HC blade even after near 100 strokes. Perhaps, I'll try a finer grit with a different steel. Also, HH may operate this technique better. Then I made a paper strop from an old college text book, cutting it with a bandsaw 2" from the spine, stood it up, attached the brace boards and began stropping my blade of 440C. This really worked!! In short order it removed the burr, not convexing the edge or refining it. I'll continue exploring this method which HH came up with as I wanted to utilize this for knife maintence with little metal removal. DM
 
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David Martin said:
Yes, that is the member. I read it several times as it was a very good read. Quite historical and factual and piqued my interest toward blade maintenance with little metal removal as I didn't care for leather stropping because of what it did to the edge. So, I tried it on a 2X7" oak board using 220-250 grit with low success. It didn't remove the burr on my 420HC blade even after near 100 strokes. Perhaps, I'll try a finer grit with a different steel. Also, HH may operate this technique better. Then I made a paper strop from an old college text book, cutting it with a bandsaw 2" from the spine, stood it up, attached the brace boards and began stropping my blade of 440C. This really worked!! In short order it removed the burr, not convexing the edge or refining it. I'll continue exploring this method which HH came up with as I wanted to utilize this for knife maintence with little metal removal. DM
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Getting the right mix of abrasive and oil is a bit tricky, takes some trial and error. I've compared these edges to ones produced with several other means and they stand up very well. Plus, it definitely seems to remove less metal even when doing some work and not just a fast touch up. It also completely fouls up whatever abrasive one is using and needs to be wiped off and reapplied if any amount of stock removal has been done. Not sure what the going rate is for a pinch of diamond grit but something to consider. I'm still working on the same 1/2 block of Sears black compound I've had for several years. For 2 bucks I might treat myself to a new one just to have. Had to buy a new block of Flexcut Gold because I'd broken the old one into a bunch of smaller pieces and slowly lost most of them. I don't anticipate needing another in my lifetime unless I start doing hand sharpening for a side job, and that's not likely.
 
I am going to craft up a wooden jig that will hold my DMT stones at 20 and 15 degrees angles off of vertical to aid in SharpMaker reprofiles. Of course I may just spring for the diamond rods themselves but there is just so much surface on those big 8" DMTs. Of course to do it right, I'd need to get another one and that's a lot of money right there.
 
Hoosier, A forum member 'trevytrev' built a jig to hold his stones at a chosen angle, something like you describe. You might find him and see a photo of this and get some ideas.
Thanks, HH for the insights on this method as I like the way it works. DM
 
:thumbup: Good post HeavyHanded!

Around 6months ago, I stropped using the top edge of the phone book loaded with CrO, result was so so. Inspired by your post, I made a new 1.25x8 top-grain tightly packed paper strop. Use a blow torch put melted wax on it, to thicken the paper & reduce the amt of abrasive from falling-between-paper. Scrapped surface to remove excess wax (hardly any). Poured a 0.25ounce of oil-base 0.5um diamond suspension, took 10 minutes to rubbed it it. Dried for 2 hrs.

Opinel#9: Start out dry-shave sharp. Dull with rock, no longer cut printer paper. Strop sharpen like mad for 15 minutes, cut printer paper. DMT E & EE it to crosscut newsprint. Strop hard for 5 minutes and slowly lessen until feather pressure another 5minutes. Snag when cut newsprint. More feather touch strop, still no-go. Use wood stick to fold over the wire & burr, holy cow a ~40um wire! Deburr with EE. Crosscut OK. More light strops, another wire appeared. I sucked at stropping. This diamond charged strop can really cut carbon steel fast!

Buck119 (420hc): Start out crosscut sharp. Light pressure strop 6 strokes/side. Woah, instant wire! Try various stropping motions/angles without luck, wire is bigger. Deburr with EE, crosscut fine. 2 strokes/side, a small wire again. Deburr then 1stroke/side - yeehaa a quiet crosscut.

Leading-edge anyway, lol - stop after 2 strokes, save this strop from decapitation!

In all, 1 stroke/side that is all I would use to give clean edge extra crisp.

**** Last night 20121205 ****

Opinel#9 & Buck119 & boxcutter:
a) Sharp. Make dull. Sharpen using S30V blade (as 4% VC stone/rod). Crosscut newsprint.
b) Sharp. Make dull. Sharpen using CPM-M4 blade (4% VC + 5%WC stone/rod). Crosscut newsprint. Get here half amt of time as (a). Amaze on the amt of swarf on the m4 blade/stone (spine, blade and mirror bevel).
 
bluntcut said:
:thumbup: Good post HeavyHanded!

Around 6months ago, I stropped using the top edge of the phone book loaded with CrO, result was so so. Inspired by your post, I made a new 1.25x8 top-grain tightly packed paper strop. Use a blow torch put melted wax on it, to thicken the paper & reduce the amt of abrasive from falling-between-paper. Scrapped surface to remove excess wax (hardly any). Poured a 0.25ounce of oil-base 0.5um diamond suspension, took 10 minutes to rubbed it it. Dried for 2 hrs.

Opinel#9: Start out dry-shave sharp. Dull with rock, no longer cut printer paper. Strop sharpen like mad for 15 minutes, cut printer paper. DMT E & EE it to crosscut newsprint. Strop hard for 5 minutes and slowly lessen until feather pressure another 5minutes. Snag when cut newsprint. More feather touch strop, still no-go. Use wood stick to fold over the wire & burr, holy cow a ~40um wire! Deburr with EE. Crosscut OK. More light strops, another wire appeared. I sucked at stropping. This diamond charged strop can really cut carbon steel fast!

Buck119 (420hc): Start out crosscut sharp. Light pressure strop 6 strokes/side. Woah, instant wire! Try various stropping motions/angles without luck, wire is bigger. Deburr with EE, crosscut fine. 2 strokes/side, a small wire again. Deburr then 1stroke/side - yeehaa a quiet crosscut.

Leading-edge anyway, lol - stop after 2 strokes, save this strop from decapitation!

In all, 1 stroke/side that is all I would use to give clean edge extra crisp.

**** Last night 20121205 ****

Opinel#9 & Buck119 & boxcutter:
a) Sharp. Make dull. Sharpen using S30V blade (as 4% VC stone/rod). Crosscut newsprint.
b) Sharp. Make dull. Sharpen using CPM-M4 blade (4% VC + 5%WC stone/rod). Crosscut newsprint. Get here half amt of time as (a). Amaze on the amt of swarf on the m4 blade/stone (spine, blade and mirror bevel).
Click to expand...


At some point the density and fixation of the abrasive makes a strop more like a hone, and clean edge trailing becomes ever more difficult. A while back I was trying compound on wood and it just wasn't working well - between the swarf quickly fouling the top layer of compound, and the unyielding backing, results weren't very good. Likewise, when I tried adding a drop of oil to some compound worked into newspaper wrapped around a stone, the compound would move around too much on the paper and loose its bite - would still work but not well. That's around the time J D Wijbenga posted the link and the techniques described stuck with me. Tried compound on wood with a drop of oil and it worked but not so good. Scuff up board with a rasp and worked better but results faded with the scuffing and were difficult to manage. Scribing the board with a saw blade works better yet - still some trouble with recurve edges as there's a smaller reservoir of abrasive slurry along the radiused corner of the board. Nothings perfect, still works well.

When I tried out the endgrain paper strop, was impressed at how fast it worked with same light pressure as I use on paper wrapped around a stone (with compound). Overall results as far as edge characteristics were about the same. Holds onto a toothy edge a bit longer but will still smooth one out over a short period of maintenance stropping, and so set it aside for a few. Came back later and made some plain ones - was impressed at how much better it worked for deburring and light final polish - even stopping at relatively coarse stone values. Currently this is where I'm finding it most useful. If an edge needs more restoration than that, I'd rather use the board or maybe go back to the last stone if needed. Loaded with a very small amount of compound they still work very well for finishing but, you can only push a given method so far and then you're stepping outside what it does best.
 
Good idea! These documents seem to have spurned new ideas and made people aware of old knowledge. :-)
 
The best part is these techniques seem very rudimentary based our notions of what makes a good sharpening tool or methods. In fact there are nothing more than fundamentals and these techniques works perfectly well, still applicable today. As I mentioned in another thread, was able to start an edge with the fine side of a combination stone and refine it with two grades of compound on hardwood till it would whittle a hair. It helps that I'm using manufactured abrasives, but as evidenced in the articles, the traditional abrasives work very well too. Yet another alternative to the question of "which stone should I buy?"
 
Yes, rudimentary and very old yet very effective. I think this goes beyond the workings of a leather strop and is quite simple and flexiable. Allowing the user to take the blade to various grit levels easily and match your preference. Thanks, JD for bringing forward this historical knowledge. DM
 
HeavyHanded said:
At some point the density and fixation of the abrasive makes a strop more like a hone, and clean edge trailing becomes ever more difficult. A while back I was trying compound on wood and it just wasn't working well - between the swarf quickly fouling the top layer of compound, and the unyielding backing, results weren't very good. Likewise, when I tried adding a drop of oil to some compound worked into newspaper wrapped around a stone, the compound would move around too much on the paper and loose its bite - would still work but not well. That's around the time J D Wijbenga posted the link and the techniques described stuck with me. Tried compound on wood with a drop of oil and it worked but not so good. Scuff up board with a rasp and worked better but results faded with the scuffing and were difficult to manage. Scribing the board with a saw blade works better yet - still some trouble with recurve edges as there's a smaller reservoir of abrasive slurry along the radiused corner of the board. Nothings perfect, still works well.

When I tried out the endgrain paper strop, was impressed at how fast it worked with same light pressure as I use on paper wrapped around a stone (with compound). Overall results as far as edge characteristics were about the same. Holds onto a toothy edge a bit longer but will still smooth one out over a short period of maintenance stropping, and so set it aside for a few. Came back later and made some plain ones - was impressed at how much better it worked for deburring and light final polish - even stopping at relatively coarse stone values. Currently this is where I'm finding it most useful. If an edge needs more restoration than that, I'd rather use the board or maybe go back to the last stone if needed. Loaded with a very small amount of compound they still work very well for finishing but, you can only push a given method so far and then you're stepping outside what it does best.
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Good points.

I consider this type strop surface has 3 components: foundation, short end fibers (bristles) and fuzz. Foundation for standard strop action. Bristles brush/polish/refine small teeth. Fuzz lap (trailing only) larger teeth. At 22x mag, I can clearly see bristles on strop however the abrasion seem too aggressive - maybe a larger non-diamond/cbn/bn would do a better job.

I'll try fuzzed-up strop surface with 0.5um, 6um and paperwheel white-compound (15um). Apply each on a D2 blade right after re-sharpened on Dmt C.
 
I used hack saw blade to fuzz-up the strop using cross hatch scrape. Experiments on a buck 119:
1) strop charged with 0.5um oil-base diamond suspension
a) DMT X -> strop. 20 strokes/side yielded optimal edge, crosscut newsprint nicely. Got wire/burr started around 25th strokes/side.
b) C -> strop. optimal around 15 strokes/side. wire beyond...
c) F -> strop. optimal around 8 or 10 strokes/side. ditto
e) E -> strop. optimal around 3 strokes/side...
f) EE -> strop. optimal 1 strokes/side ...

2) charged with 8um water-base diamond suspension
a) X -> strop. wire/burr after 30th stroke but stay small even after 60 strokes/side. w/o any sign of rounding.
b) to f) optimal strokes about the same as in 1). same wire/burr as in 2a). hmm :confused:

3) charged with white-compound (for use on slotted paper wheel)
a) X -> strop. The strop got blacken very quickly. After 25th strokes/side, the edge can cross-pushcut newsprint smoothly. After 75strokes/side the edge still super-sharp without any wire/burr. I increased the pressure to about 5 lbs, after 10 strokes, I finally get a tiny wire, failed to push cut.
b) to f) proportional to optimal. ditto for sharpness & lack of wire/burr.
g) Endura vg-10 won't crosscut newsprint starting out. Strop for 20+ strokes/side, wow - cross pushcut, dry shave. another 50 strokes, still dry-shave. 5 lbs of pressure, ok got a wire but much smaller than diamond compound.

:confused: someone please duplicate 3) :thumbup:


Edit: Reproduced experiment (3)
Fuzz up, charged with white-compound, light fuzz up.

Got same results as (3) above. Cross push-cut newsprint & dry-shave for: Endura vg-10, GB cpm-m4, bm940 s30v, stretch cf zdp-189.
Fresh strop
stroppaperendgrain20121.jpg


After heavy (with pressure considered be excessive for normal strop) stropped 4 knives, crazy sharp knives
stroppaperendgrain20121.jpg
 
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btw with 20x loupe, I didn't see any visible convex nor rounded edge for the 4 knives above. Tomorrow, I'll light up my usb microscope to see what those edges look like under higher resolution. Cautiously I'm stoked, finally a strop yields sharp edges without (so far) burr/wire/rounded edge.

edit fyi: just in case paper make a difference. I used end-grain paper from printed uline.com catalog. You can see the catalog spines on the left side of the strop.
 
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You are welcome! But really the people who wrote it should be thanked. This is the start site that links to pdf's (in Dutch) with some information about the authors.
 
With a 400x usb microscope, I see some small burr on the s30v & m4 & vg10 knives. No sign of common convex problem associate with stropping for 4 knives (endura, bm940, gb, stretch cf). Burr was easily stropped away on bare leather. Did a complete dry shaved using 4 knives, smooth but got a minor burn.

Next, I strop the endura on white-compound charged balsa, leather, parrallel-grain-paper(using a catalog top-bottom side edge) strops. Convexed & burr like crazy were the results. Also each strop got blacken (talking about jet-black) very quickly, yup quite a bit of metal was abraded.

Took the overly convexed (won't crosscut newsprint) endura, dulled it a little on a rock. I stropped it for ~15minutes on the end-grain paper strop loaded with white-compound. It cross-slice-cut newsprint. 30seconds strop on bare leather. It's now cross-push-cut newsprint. Back to strop on end-grain paper strop for another 10 minutes, it's barely cross-push-cut newsprint. Made a few cut into scrap leather, it's smoothly cross-push-cut again. Which indicated weak burr (not tenacious type).

Again, it would be great to see confirmations from others :thumbup:
 
bluntcut said:
With a 400x usb microscope, I see some small burr on the s30v & m4 & vg10 knives. No sign of common convex problem associate with stropping for 4 knives (endura, bm940, gb, stretch cf). Burr was easily stropped away on bare leather. Did a complete dry shaved using 4 knives, smooth but got a minor burn.

Next, I strop the endura on white-compound charged balsa, leather, parrallel-grain-paper(using a catalog top-bottom side edge) strops. Convexed & burr like crazy were the results. Also each strop got blacken (talking about jet-black) very quickly, yup quite a bit of metal was abraded.

Took the overly convexed (won't crosscut newsprint) endura, dulled it a little on a rock. I stropped it for ~15minutes on the end-grain paper strop loaded with white-compound. It cross-slice-cut newsprint. 30seconds strop on bare leather. It's now cross-push-cut newsprint. Back to strop on end-grain paper strop for another 10 minutes, it's barely cross-push-cut newsprint. Made a few cut into scrap leather, it's smoothly cross-push-cut again. Which indicated weak burr (not tenacious type).

Again, it would be great to see confirmations from others :thumbup:
Click to expand...

To some extent I'm seeing a lot of what you're finding with a few exceptions. When stropping on hard leather or newspaper (flat, on a stone) I only get so much convexing and very little if any burring with compounds smaller than approx10 micron. So - black emery I can raise a burr tho it will be visibly convexed. With white or yellow compound I can convex easily but not raise a burr. Suspect much pressure involved. I can fairly easily raise a burr with even the white compound on wood (mixed with a drop of oil as described) but there is no trace of convexing, can go from wood to stone and back with no extra work flattening bevels. Also, stropping on a single sheet of paper wrapped around a stone the convexing is pretty mild - very easy to go back to a stone and get flat bevels with very little work, tho there will be substantial smoothing of the grind pattern 'teeth'.

The endgrain strop is much more resistant to sagging, so far less convexing. Also, the endgrain strop with no compound is much better at removing small final burrs than a flat piece of paper or plain leather (IMHO) - probably because of higher spot pressure. One other thing to experiment with - if you can duplicate on the loaded endgrain strop with a good degree of precision, the angle at which you did your stone grinding, you'll see a marked improvement in 'tooth' retention even while producing a very good polish. This effect diminishes after a couple of stroppings and the edge will smooth out, but it makes for a very good combination of cutting characteristics. Swiping the grind pattern across the loaded strop will smooth it out just as it would with a single sheet of paper over a stone or hard leather. Still a good pressure cutting edge but will loose some draw cutting efficiency as you go.
Was able to completely refresh the surface of the strop by rubbing with a coarse benchstone and so do many tests with loaded/plain stropping.

Have fun, this seems like a pretty good find!
HH
 
Yes, I've noticed the same characteristics as you two describe. The end sheet paper strop, removes burrs faster and with less convexing at the edge. The edge turns out nice and clean, thus cuts well. DM
 
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