What are your next "mad scientist" sharpening experiments?

T

thombrogan

Joined
Nov 16, 2002
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I've got a bunch of ones inspired by HeavyHanded that all involve stropping with either coarse grit media and/or with newspaper coated with the slurry of a waterstone just used for sharpening. Also wanting to muck with Crystolon or similar SiC oilstones and AlOx oilstones (for which I blame HeavyHanded and David Martin and Phil Wilson and Jerry Fisk and almost everyone in the Becker subforum).

Another one involves a straight-razor honing technique called "pyramiding" where you strop at one grit for a set number of passes, go to a finer grit for a slightly lower set number of passes and repeat to your OCD-addled heart's content.

Can't wait til I have the time... :rolleyes:

What are your upcoming exciting and utterly impractical sharpening experiments? Chasing down any natural stones from your neighborhood that'd give the finest, most expensive natural stones from Arkansas, Belgium, or Japan a run for their money? Hacking one of those Mindflex games so you can set the bevels on your folders without touching them with your hands? Training crickets to detect and remove burrs? Comparing the forced patinas of various dijon mustards? Comparing the effects of various types of bacon grease on your loaded strops (bacon makes everything better)?
 
Right now I'm following up on my experiment with the soft Arkansas lapping/slurry block on my waterstones. I got to thinking (I usually reserve that sort of thing for AFTER I've spent a ton of effort in a given direction) about creating slurry with another stone. Any stone that's not matched is problematic, and grinding away on the waterstone to create a stropping slurry is not a very efficient way to go either. Then I remembered a thread in a woodworker's forum where one of the respondents stated he used an old plane blade to create a nice swarf/slurry on his waterstones for doing touch-ups. Well, I scrounged up a chunk of mild steel and used it on my waterstone to whip up a slurry for stropping and it worked great. I figure it still strips off some abrasives, but the steel itself imbedded into the paper should be capable of removing smaller burrs and polishing an edge. I don't have to worry about mismatched grit in my slurry, but on the other hand it also prevents me from generating a thick mud right from the get-go, so it may not be possible to get all I want from this method.

Tried it and it works quite well, results are very similar to stropping on a stone generated slurry, so now to monkey with this for a few and see if it holds up at different grit values and steel types. Am also going to see if using it on dry or wet newspaper makes much difference. Not as convenient, but I suspect putting it on paper and letting it dry will yield the best results.
 
I wish that I coult take credit for this idea, but I borrowed it from a fellow on another forum. And it would be less than honest to take credit for it.

I've been experimenting with placing plastic clips of various sizes on the spine of sharpened knives, and stropping them on a hanging barber strop.

Laying the blade flat on the strop, with the spine raised a bit by the clip, and stropping the knife in the same manner that one would strop a razor.

I haven't worked out all of the details yet, but it has worked marvelously on a Bob Dozier, and a couple of Spydercos. (Of course, I also rounded off and dulled a few in the process!:D )

So far, the results look quite promising,:p although getting the thickness of the clip to raise the spine enough to allow the edge to barely touch the leather is somewhat of a challenge. :confused::confused:
 
I don't know what else to do, I've sharpened on the flat of a 36 grit grinding wheel and a cinderblock, so I don't see any point in going coarser. Looking at ordering some 0.125 micron CBN to see if it makes a noticeable difference. I doubt I'll get the 0.025 micron poly diamond spray, but never say never.
 
Hardheart, After sharpening on those coarse surfaces how did you then remove the burr. Did it cut acceptable?
Or were you expressing your sense of humor? DM
 
I have started using diamond files to shape my edges. Keep the knife still while I file away at the edge. I am able to get better results this way, and I can really work the choil and tip. Recurves and hawkbills are no problem. I would really like to try a guided system like the edge pro but I keep spending my moneys on other things.
 
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David Martin said:
Hardheart, After sharpening on those coarse surfaces how did you then remove the burr. Did it cut acceptable?
Or were you expressing your sense of humor? DM
Click to expand...
I used feather light passes on the stones to finish, same as with fine grit stones. They cut okay, obviously very rough. Shaving arm hair was still possible with no problem.
 
Ok, you enjoy the coarse edge. Offering utility with a minimalist approach. As long as it offers the edge you like. DM
 
Replaced my HF belt sander earlier this year with a Viel and have not played around with anything other than different grits on the belt sharpenre since.Kind of hoping this thread will spark my interest in trying something new.
 
I'm trying to make my manix 2 less hallow ground, wish I had a belt sander,
 
Finally tried sharpening on a coarse waterstone (Naniwa synthetic Omura) followed by stropping on a shop towel laden with its mud to reduce the burr. Found out that the burr would just tear the shop towel. Moved up to a King 800 grit and couldn't get rid of a flip-floppy burr until cutting very lightly into the waterstone and then resharpening. After lots of careful edge-refining/burr-reducing passes on the King, there was still a slight burr on the edge, so I moved to a leather strop sprayed with 0.5 micron mono-crystalline diamond (strop, base, and spray were all Hand American). Result was a very sharp edge with a highly polished microbevel.

Findings so far as my pea-brain surmises:
1. Shop towel is not a strop towel
2. The Naniwa synthetic Omura works its best when it has a slurry built up and gets its slurry built best sharpening with lots of pressure. Definitely not a "let the stone do the work" stone.
3. 800 grit waterstone + 0.5u micron diamond makes for a wickedly sharp edge on 13C26 as heat-treated by Kershaw. Wondering how it'll work one Hitachi Blue #2 as heat-treated by Moritaka.

Avenues for further study:
1. Newsprint as potential strop towel
2. Stropping on hubcap polish instead of diamond
3. King 800 + Hand American diamond on other steels
 
I've been working with waterstones a lot, both synthetic and natural. I will be getting my first waterstone coarser than 1k, a Nubatama 150 grit, and probably making a set from the bamboo series. I've also taken a liking to finishing with a natural stone and have given up on strop compounds in favor of horse hide or newsprint for the final touch.

I've started sharpening Japanese kitchen knives which has been a interesting and refreshing adventure. Lots of different knives and new sharpening techniques to learn so I think it will have my interest for a while.

My Mad Scientist experiment of late has been to find a way to de-burr without changing the edge qualities the stone produced. So far its been the horse hide or newsprint but each will do too much if not careful. I have been thinking of HA films with finishing stone slurry as compound but its something I've still yet to try.
 
My next trick will be finishing the repair/regrinding of my Kudu down to 0.005" or so behind the edge, then sharpening on my coarsest stone. In the past, this knife took a nice edge off the 220 green King waterstone. I want to carry it a while with a edge angle of say 15 degrees inclusive with that finish and see what happens.

My other experiment is in progress, and involves regrinding my Cold Steel machete collection (Kukri, Barong, Panga) to give them primary bevels and sharpened edges comparable geometry to my Parker Cutlery slip joint. See the soon to be Barong review in the Testing forum for updates.
 
I too think it doesn't take much stropping to change the edge left from the last stone and to convex the apex. Hence, wanting that last grit and V, I've begun removing the burr left from the x-coarse diamond by taking it one stone finer to the coarse. With just a few light strokes it removes the burr adding little refinement
to the edge allowing the better edge retention I enjoy. The cutting edge is a personal choice and when arriving at your taste, mediums and technique play a big role. DM
 
Well, I now have confirmed one instance of a poorly-formed edge from a 700 grit SiC waterstone comes off the strop as a shinier, poor edge. Good to match the a priori with the empirical when making an anecdote. Also found that going over that edge and adding a microbevel with 5,000 grit AO waterstone followed by stropping on loaded leather, paper w/CrO/AO buffing compound and finishing on bare paper makes for a pointlessly sharp show-off edge. Another good match.

Finally got some newsprint, so I can try the sharpening on a 700 or 800 grit waterstone and finish by stropping with its slurry like HeavyHanded has been doing. Quite psyched.
 
Attempt one at newsprint was a fail. Didn't raise enough slurry on my grit-leaking SiC wonderstone and the newsprint bunched anyways. Remembered to form a full-length burr with the wonderstone this time, so that was good. Stropping on bare cardboard didn't deburr either, but the knife some nameless semistainless steel, so that can be expected. Moved onto the leather strop with 0.5 micron diamond spray and got a happy edge that should be great for carving roasts, but still look forward to trying again soon.

edited to add:

The 700 grit edge followed by 0.5 micron diamond compound (700 grit JIS is coarser than 400 grit wet/dry) was perfect for kielbasa and peppers, great for tomatoes and potatoes, and regretful for onions (did a great job, but wasn't polished enougb to reduce the tearing). Very psyched.

Keeping checking for me2's updates in testing and reviews.
 
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Here's my latest (I try a lot of stuff). The stone and swarf slurry from my waterstones worked very well, but the wet paper allows too much rounding of the apex, and its not practical to sit and wait for the paper to dry before finishing an edge. Dry paper works better, but has a harder time deburring and doesn't work very by itself well for maintaining a microtoothy edge.

I also noticed something peculiar when stropping a coarse edge with newspaper wrapped around a SiC stone for more firm backing. Using a bit of pressure worked great until small V shaped microburrs started to form perpendicular to the edge - thin(er) spots in the bevel where a large grit dug deeper than its neighbors collapsed under the pressure from the uneven surface under the newspaper (one layer). This is not good, but it did lead to two conclusions - don't use too much pressure stropping on a hard, uneven backing under newspaper if you have a coarse edge on a fairly acute inclusive edge angle, the pressure spikes will cause trouble - and... this might be a principle I could make use of...

Bring on the crayon-type compounds.

I rubbed a single sheet lightly with some Sears white compound ( I estimate it at 1-3u), wrapped it around the fine side of a SIC stone, and stropped just hard enough to feel the texture of the stone through the paper. After a dozen passes I wrapped a second, undressed sheet of newspaper around the first and stropped on that, again just hard enough to feel the texture of the stone. This works absolutely wonderful for creating a relatively refined toothy edge - looks very much as it did fresh off a 4000 grit waterstone and stropped on plain newspaper. No rounding of the apex, and no erasing the grind pattern. The pressure spiking of the stone texture under the strop abrasive causes it to carve into the edge without issues of rounding the apex or polishing the scratch pattern too much. I did a few other tests using both sides of the stone with different sized stropping abrasives on edges prep'd from different grit stones. In every instance it worked very well at preserving/refreshing (in truth, regrinding) the scratch pattern without raising a new burr or rounding the apex. I suspect I could use a smoother stone (my Spyderco Fine) in conjunction with CrO to do the same treatment on an edge coming off of the 6000 or higher waterstone, and will be testing this soon. I went down as low as 120 grit SiC dust and was able to cut a coarse edge into a previously dull blade and coax it to cut arm hair and pushcut newspaper with the grain (had to draw cut to go across the grain).

All pics at 640x - scale at upper left is 7.7u

Original edge sharpened at 4000 and cleaned up on newspaper strop - could pushcut TP and part freehanging TP with a light swat:
Mora_4000KWS_SonS_640_cal-1.jpg


Same edge after much tinkering with some Flexcut gold compound - a bit too refined for my purposes, but a nice edge nonetheless - could pushcut TP more cleanly but was starting to have trouble swatting a free-hanging piece:
Mora_Lam_4000KWS_Strop.jpg


Same edge after the white compound - no rounding and very microtoothy - almost a dead ringer for the original edge straight from the stone in looks and characteristics. In truth it performs better, and the grind pattern is almost entirely created by the stropping procedure :
Mora_L_4000KWS_Strop.jpg
 
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I'm going to try stropping on leather with my DMT Aligner. After finishing on my finest stone, I'll simply pull the rod out of the angle guide & carefully strop at that angle, letting the outside of the angle guide eye drag gently on the strop. That extra 1/16th or whatever of plastic will provide for the slight microbevel I'm after & keep me from botching my hard-earned edge. Turning the blade clamp knob back can even reduce that microbevel a bit if I need to. I haven't tried this yet but I'll be dulling a knife soon enough.
 
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