Coarse edge stropping

Yes, agreed . It is a very deep rabbit hole and perhaps with no ending . Your last sentence is a conclusion I've been pondering . DM
 
HeavyHanded said:
I'm starting to believe that blade life and different grinds is largely an individual user aspect. When using a fine edge on my hard-use knives and using a primary/secondary bevel I found myself having to reestablish the secondary bevel so frequently that it was removing a lot of metal to keep it in good shape. With a fine edge and a single bevel one still has to drop down a few grit levels from time to time and that eats steel as well. With a hard used coarse edge I'm only using a single bevel and can refresh it with just a few passes even if it's pretty beat up. It's difficult to say for sure which removes more metal in the long run. The casual user will likely get more life from a fine edge, but a coarse edge done well and used casually can go for many long months with zero attention. I am slowly coming to the conclusion that the easiest edge for most people to achieve and maintain is somewhere in between the two. Getting a high quality coarse or fine edge requires a little more understanding of all the variables with respect to steel and grinding media. It is very much like jumping down the rabbit hole. For each steel type and application there's going to be a perfect grinding media and edge angle etc.
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Agreed, yes a deep rabbit hole and each 'best' is hard to find . I've noticed on my coarse edges I can easily refresh them on a 200 grit finer stone . DM
 
Some way it got it right on the second post but completely missed another post . It gave more time to think . Edge retention does have many variables and I'm willing to chase that rabbit for a while inorder to see what I can learn . Maybe only about 2-3 steels the rest is a lifes work . Heavy, you mentioned cutting large fish scales, I've done that . It was on a 62lb. Gar and their hide is like plate . The scales are larger than silver dollars . I split him on both sides so the hide could be removed using a 4"blade of 440C sharpened at 220 grit . One cut down and another cut on the opposite side which took a good bit
of force and gutted him some and the blade was done . It was real tough . DM
 
For each steel type and application there's going to be a perfect grinding media and edge angle etc.
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While that is true, you will also have the end user as a variable as well, their cutting media, cutting style, and sharpening tolerance/tools/ability.
 
Well, I sharpened the D2 blade today . First on a Norton fine crystolon 280 grit establishing the bevel, then to a 450 grit NOrton fine India, on to a 600 grit X-fine India . It was at this stag that I really began to notice the edge becoming very sharp and echos coming from my brain, 'be careful' and examined the edge using 10X . Then on to a Translucent Arkansas and finally the black hard Arkansas and strop . Now, cutting sisal rope . Though I tried several times even touching it up on the black and more stropping the blade would not cut 1/4" sisal rope . I tried several different styles of cutting; push, pull and stroke, forward and back . Still, it was with these efforts combined that I was able to obtain 3 cuts . Yet, it cuts paper leaving no fibers on its edge and shaves arm hair effortlessly . Without any burn . So, I think with this steel I'll have to change the cutting medium inoder to move ahead with the test . This steel takes a polished edge well . Also, thru these tests I've come to realize a polished edge while shaves well . Its not a good choice for general cutting . I've noticed this on several occasions . I'll thaw out chickens and start cutting these on another day . DM
 
HeavyHanded said:
Only at normal grit ratings (300 - 8000). Much like yourself, and many others here I've noticed that some steels do not respond well to all grinding media.

To the best of my knowledge there's only two types of grinding media commonly available at under 100 grit, SiC and AO, with the later generally stuck to a belt. This really limits what can be done to test in this area, but how much larger a grit could you really go than the 60-80 range? If you're aware of any other materials I could be testing in this range, let me know! I know that belts come as large as 36 grit, but can one really hand sharpen on this? Once you put it on a belt, your results are going to be very different. A 320 grit power belt-sanded edge looks like a 1000 grit or better off a hand stone (IME).

HH
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This has been a great thread to read and has given me so many ideas. Thank you guys. I have some diamond stones at 50# and 80# and quite a lot of different stropping compounds. Heavy, if you would like to recommend some tests you'd like done with those coarse diamonds, please let me know and I'll perform them and report back.
 
DM, I didn't realize but I use sisal rope often in the summer for tying up the plants in the garden. I'm surprised you were unable to make a push cut through a 1/4in piece, to me its similar to manila rope in that both cut best when using a push cut style with a polished edge. I'm a little confused by your post though, were any cuts completed?
 
Ouch DM, was that 1/4" free-hanging? Frankly I'm surprised the performance was that dismal. In the past I've gotten a polished edge to cut 3/8" sisal with no real issues, even if it did take a lot of pressure (compared to a coarse edge) to do so. What approx angle was the edge bevel?

HH
 
clayallison said:
This has been a great thread to read and has given me so many ideas. Thank you guys. I have some diamond stones at 50# and 80# and quite a lot of different stropping compounds. Heavy, if you would like to recommend some tests you'd like done with those coarse diamonds, please let me know and I'll perform them and report back.
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Thanks for the offer, truth be told, I'm not sure what test works the best. Assuming you can get a burr free edge at 50 grit, you could try sawing through some newsprint across the grain. I've found with a really coarse edge it'll catch so much you can only get it to cut with a draw and using a very light touch. Draw cutting through natural fiber rope is another good one, as well as free-hanging fabrics/canvas. Edge retention is the real test though, how long does it stay functional with a fair amount of abuse?

Where did you get a 50 grit diamond stone?!

On a related issue, I'm coming to the not-so-novel conclusion that stropping grit needs to be matched carefully to the grind pattern for best results. I recently observed a small burr on 154cm getting polished nicely on CO but it wasn't being removed at all (after 30-40 strokes). This could lead to some very misleading if temporary results. This is the same knife I stropped on black emory and it not only removed the burr but left it with a nice microserrated edge - it didn't buff out the grind too badly. It could probably be used to maintain it for several stroppings before the edge looses it's tooth, though for this experiment I'm working with 200 grit, not 60.

HH
 
The angle was around 17* . Yes, I was able to do 3 cuts . Also, I measured the edges and the D2 blade was .0051 whereas the blades that I had used in previous test were half that (a factor). Now if I approached cutting the rope like celery ie. push cutting it against a stiff backing like a cutting board then it could do it . But with the method of one end of the rope in a vise and the other end I was holding perhaps 15" away and attempted the cut near my hand it just would bind up and skate . So, this approach could be different . In previous tests this same type edge was a challenge in getting it to cut after sharpening on a Arkansas stone . I'll admit its frustrating after examining the edge and no burrs, its sharp and won't cut this material . But I'll move on to a different medium more to its liking . No other conclusions at this time . DM
 
Yes, I've had previous success cutting sisal rope when I changed the factors . ie. a thinner edge, 2) using stainless (heck, I even obtained good cutting with 01 steel with a thinner edge) 3) sharpened on a different medium (ceramic or water stone gave good results) 4) cutting with a hard backing . DM
 
Come to think of it, in the past I've always just made a loop and pulled against it - a much more secure method, but after having you describe your method I'm a lot less surprised.

HH
 
My other tests were done in this same manner . It worked then and I'm just continuing the same tests . This threw me a curve and after thinking about it during the day I'll offer a couple of possibilities . Granted encountering this scenario three times does not give extensive knowledge . One the Arkansas stones finely polish removing bite and when cutting rope in this manner it creates snafu's . Whereas if one were shaving this would be the correct edge and stone . Two, edge thickness matters much in this type cutting . The chickens are thawing and this blade and steel should fare better with that medium . DM
 
I began cutting up chickens and it occured to me that I should atleast describe what I'm doing as most persons don't do this with a knife . Most Housewives today purchase split breast or boneless, skinless breast chicken not whole fryers . Whereas the value is in the whole fryers in far cheaper/lb. still offering all the same cuts just requiring dissecting . This is a good normal test available at home as most of us eat chicken once a week . There are 9 edible pieces of chicken in a whole fryer not counting the neck and back which if used at all is put in soup . The cuts are; 2 drumsticks, 2 wings, 2 thighs, 2 split breasts and one pulley bone/wishbone . So, I'm removing these for table fare . This requires slicing thru the skin,meat and some bone . I noticed the knife sharpened in this manner will remove the drums and wings acceptable and cuts more sluggish on the remainder . Whereas the same knife sharpened at 280 grit cut more agressive on all parts . Something to consider when sharpening kitchen and hunting knives . The test is ongoing and I'll try to finish up this evening . DM
 
Ok, I've finished the test and the deep rabbit hole looks like this: Nine chickens cut up before the edge is really not even able to cut open the plastic shrink wrap covering the birds . I had to make 5,6-8 slicing strokes (some here refer to it as sawing)to open the plastic wrap . I pressed the knife one further but it was a struggle . I would have touched up the edge at 8 and no more than 9 . Interesting that this is exactly half what the more coarsely sharpened edge cut up . Here I've provided for you tests inwhich three times this pattern emerges using 3 different steels and different tests mediums, where --- the more coarsely sharpened edge demostrated greater edge retention . Upon, examination of the edge under 10X magnification I noticed numerous pinpoint size burrs all up and down the edge . Not one quarter inch of the edge was lacking several burrs . For some reason I'm not hungry for chicken tonight . DM
 
Thanks for the work DM. This jibes with pretty much everything I've found doing my own testing. Honestly, I'd like to hear about any studies that refute this finding, as there's always more to be learned.

HH
 
Your welcome . This edge retention stuff may not be as complicated as some are making it out to be . Could the general rule be the obvious, that the more coarsely sharpened edge gives greater retention over the more finely sharpened regardless of steel type and grit type has some effect . Plus, some sharpeners may not get good edges until they take it up to 600 grit but this seems to speak of technique . DM
 
Just a bit of trivia related to this. I just got my first strop ever so I've been playing with it a lot and stropping anything I can get my hands on. Sounds funny to experienced people for sure I bet, but it surely was a missing link here...fantastic results! BF to thank for this as I'd never really thought about a strop before.

On a tip from a friend about coarse edges, I took a new Buck Nighthawk short that I got that had a very coarse factory edge on it and stropped it quite a bit without reprofiling the edge like I 'normally' would do. The factory edge was quite coarse, if I had to estimate it had to be no more than a 220 finish or so...where I'd been taking all my edges through 1000 grit on the Edge Pro before stropping.

The result is a wicked sharp edge with tooth to it. The stropping with green compound took it from just generically sharp to being able to push cut paper with it and though I'm not an active knife field user, the difference casually cutting different odd materials shows me that the toothier edge works better with slippery or soft materials as indeed it seems to 'grab' them.

I actually think that for my EDC folder uses that some tooth to the blade edge grind may actually be a bit more universal for usefulness, though it's not as purty as looking at the mirror-like edges I have now.
 
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