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Chef’s knife w/ convex factory grind (Mac Mighty)

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  • #44358
    Justin Fournier
    Participant
    • Topics: 2
    • Replies: 54

    WRT the Trizact, I call it sandpaper as AFAIK it is automotive sandpaper, I believe I saw it one time while searching for 2500 grit paper to wet sand a paint blemish from an animal strike. I’m a vehicle hobbyist as well. Apparently that is not what you have, but sounds like you have a good understanding of how it might work so you might as well give it a go at some point and see what comes of it.

    WRT diamond stone sets, I only have the 1500/Glass set (6 micron DLF) past the 1000 so it’s one set, thus comparable in cost to 2 sets of Aluminum blanks, however DLF certainly costs more than Trizact though different application.

    Anyways, hope this one works out well for you. It only gets easier the more knives you do.

    #44361
    tcmeyer
    Participant
    • Topics: 37
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    This is a really interesting case, as I don’t recall ever seeing a micro-bevel on a belt-sharpened edge before.  What’s more, the micro-bevel is really small and looks to have been done with some hand honing operation, either bench stone or some guided system like WE or EdgePro or Lansky.  Somebody had to know what angle will reach the apex, as taking more strokes to find it would have greatly increased the width of the micro-bevel.  I typically use a 20 dps micro-bevel on a 17-degree edge and three very light strokes with my 1000-grit stones will make a bevel twice that width.  This one looks like a single, very light stroke with a medium-grit stone; maybe 1000-grit.

    Now that I’ve got that out of my system, I’ll have to give it a try.  I just did a batch of knives for a friend.  Most  weren’t worth more than a few dollars, so I hit them with a 600-grit belt on my 1X30 Harbor Freight sander, then a few quick passes at the buffing wheel with pink scratchless compound.  All sliced phone book paper easily.

    From what I see in Graphite’s photos and read from his posts (assuming 15 dps as the main bevel width) it looks like the blade is only about 0.006″ thick at the shoulders of the main bevel.  This means there is very little metal to be removed, no matter what the final decision is on configuration.  I would  start with 1000-grit and drop back to 800 if the progress was slow.

    Final comment:  That’s a really impressive factory edge, even without the micro-bevel.  Looking at the first and second photo, it looks like the formation of the main bevel was part of the final finishing operation – the grind lines on the faces and the bevel (convex) grinds seem to be the same or very nearly the same.  As though the fellow putting the final finish grind swept right through into the convex bevel.   I don’t see signs of a polishing step in the convex bevel and am a bit puzzled by this.

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    #44364
    Organic
    Participant
    • Topics: 17
    • Replies: 929

    Is it possible that the micro bevel that is on the knife was in fact put on by the use of the ceramic hone used to maintain the knife? It seems like a reasonable explanation to me.

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    #44369
    Justin Fournier
    Participant
    • Topics: 2
    • Replies: 54

    The one pics looks like part of it was, to me at least. The differential scratch pic. If the same hone was used, I would expect the same scratch pattern though slightly different orientation.

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    #44374
    graphite
    Participant
    • Topics: 10
    • Replies: 101

    Marc, on my angle logging comment, what I’ve been doing is logging both the coarse angle setting (i.e. the setting on the angle rod) and the fine angle (using the height gauge on calipers, measure the height of the fine adjuster screw above its holder). That way I can replicate the whole coarse plus fine position for the next time I do the same knife (assuming I position the knife itself the same). Or in theory, that’s how it would work.

    From the stone compensator videos I’ve seen, I seem to recall some stones varied enough to need to move the coarse adjuster +/- 1 degree notch, not just the fine adjuster. My trizact holders measure 1.15″ thick (across both faces) while the diamonds measure 1.18″ so they’re pretty close to start with (and the actual difference in-use is half that, so call it about .015″).

    But your question gets me thinking, while that coarse/fine logging will work when I’m trying to replicate the exact angle for using same stones I used before, I’ll really need to use an angle cube if I change to stones of a different thickness from one sharpening to another. In that case I’d need an absolute angle reference, not just a relative one. So a properly functioning angle cube would be the tool for the job.

    BTW, I previously mentioned my angle cube repeatability issues and that I haven’t been relying on it. My Wixey cube uses what they call “Dead Level” and they claim it is “permanently calibrated at the factory and should never need re-set.” They do offer up a way to override it, but I hesitate to do that since I’m not sure my issue is a calibration problem. The readings are accurate, just not to the .1 degree accuracy due to the lack of repeatable measurements. tcmeyer mentioned something interesting in that other thread (extraneous vibrations e.g. due to music playing in the background) that I had not thought about before but it does sound plausible. I’ll have to mess with it some more.

    Also, the Wixey model I have only has magnets in the base. So I’d either zero it then put the base on the stone for a hands-off approach (and subtract 90* from the result) or I manually hold the Wixey on the stone on one of its sides, but any vibrations in my hand will translate, even if I think I’m being steady. I tried both, and both had repeatability issues, but I’ll look at it again later. Using just the base has the advantage that it doesn’t include any error in the sides of the cube not being 90.00 degrees, but the disadvantage is to get a direct angle reading I’d have to hold it manually on a side face. Also, I may consider getting one of the dual-axis Floureon models since it sounds like you guys have been pretty happy with those.

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    #44375
    Justin Fournier
    Participant
    • Topics: 2
    • Replies: 54

    I often listen to YouTube or music when sharpening, and have not had issues with vibrations though I have powered Bookshelf speakers on my desk which are obviously way bigger than they should be, and an 8″ sub under my desk and I’m using the Floureon DLX360S. I am not sure the S is necessary, but for the cost of upgrade compared to what I have spent it’s nothing. I even have an AccuRemote I can send you, you can keep it if you want to try that one out. Should confirm your existing one, or perhaps they are both bunk.

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    #44376
    MarcH
    Moderator
    • Topics: 68
    • Replies: 2574

    Graphite, I’m going to interact in this current thread with you.  I have to say I’m sorry, but for me this has become tedious.  Our minds and thought processes are way different.  For me the “bottom line” of the Forum is I’m trying to help new and inexperienced WEPS users, and maybe experienced users too, to use their systems to sharpen their edges, just as those others before me graciously shared their experiences and knowledge with me.

    Your insight and though processes are way beyond mine.  You consider things I’d never consider to be of relevance.  Neither of us is right or wrong.  We’re just wired way differently.

    This is my last hoorah.  In the paragraph:

    But your question gets me thinking, while that coarse/fine logging will work when I’m trying to replicate the exact angle for using same stones I used before, I’ll really need to use an angle cube if I change to stones of a different thickness from one sharpening to another. In that case I’d need an absolute angle reference, not just a relative one. So a properly functioning angle cube would be the tool for the job. BTW, I previously mentioned my angle cube repeatability issues and that I haven’t been relying on it. My Wixey cube uses what they call “Dead Level” and they claim it is “permanently calibrated at the factory and should never need re-set.”

    I have to beg to differ with your thinking or maybe it’s your terminology here because I do want the “relative angle” not the absolute angle.  I want the ability to zero out my Wicked Edge so the vice mounted to it and the knife clamped in the vice are measured relative to the zeroed base.  That way it doesn’t matter how level the floor is or the table is, or the earth is.  All that matters is the angle difference between my clamped knife and the rod angle adjustment point as it’s attached to the WE vice, as it’s attached to the zeroed base it’s mounted on.  This angle is relative to the center of the clamped knife and the two bevels I’m sharpening.

    I used the Wixey for quite a while and swore by it.  I even argued with Tom, (TCMeyer), over it’s ease of use and repeatability, and I still stand by that.  I purchased the Floureon DXL360, to compare effectiveness after he praised it’s accuracy.  I then bought the Flureon DXL360S because it’s stats state it’s even more accurate and repeatable and there was some conversation on this Forum about the need for a better Dual Axis Meter.  All three work very well, when zeroed to my WEPS base, and give very repeatable results of the “relative angle” I sharpen my knives to.  Knives I sharpened with the Wixey and the DXL360 when mounted with my logged mounting settings are sharpening dead on the bevel, for me, now using the DXL360s.  That is simply all that matters.

    I’m going to keep trying to do things simple and uncomplicated.  Please keep doing what your doing.  It seems it’s working for you.  Maybe down the road we’ll meet some where in the middle.  Right now, my forum friend, I can’t keep up with you.  My brain hurts.  I’m bowing out.

    Marc
    (MarcH's Rack-Its)

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    #44378
    graphite
    Participant
    • Topics: 10
    • Replies: 101

    Hi Marc, not to worry. I’ve thought the very same thing in some of our exchanges, and just as you said, our brains are just wired very differently. I still value your inputs, whether you like it or not ;o) Yes I think it’s just terminology, since I don’t fundamentally disagree with what you described. I think it’s a case where if you were sitting right here next to me, by showing you the process I was attempting to describe (obviously not very well) it would all click. But as a written description it’s a challenge since the English language lacks enough word diversity on some topics. Sorry for furthering not lessening the confusion, and that was certainly not my intent.

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    #44706
    graphite
    Participant
    • Topics: 10
    • Replies: 101

    Checking back in after an impossibly busy post-holiday catch-up period. Where I left off with this MAC knife is I sharpened it at about 16 degrees (or at least that’s what my angle cube showed) with just the 1000 grit, and using my circle contour jig for blade positioning (left to right, and tilt).

    The bevels within each side were reasonably uniform, but I still have a problem with uneven bevels from side to side. This is even with concentrating on trying to do the same number of strokes and the same pressure with each hand. But I guess it’s hard to know if I’m *really* applying the same pressure give that one hand is dominant. Have any of you heard of anyone needing to make a permanent adjustment where, for example, you always do only 80% (or whatever) of the strokes with your dominant hand and 100% on the non-dominant hand?

    Anyway, the resulting edge was, let’s call it pretty sharp. But certainly not “oh, wow” sharp. I can cleanly slice-cut paper if I move the knife through fairly slowly, but with quicker swipe cuts of the paper (more of a wrist-flicking motion) it hangs up. To explain that further, if I make a slow starter cut into the edge of the paper, once the cut has started I can then do a clean slice. But banging the knife edge into the paper’s edge (as with the wrist flick motion), the paper just curls over most of the time. Is this something that has an easy cure?

    Maybe something with the direction of the last couple finishing strokes with the 1000 grit? Do you guys have a standard process you’d follow for the last couple/few strokes if 1000 grit were the max grit you’d use? I suppose it becomes less important to follow some final process of swipes if you’re taking the edge several finer grits beyond 1000?

    #44709
    MarcH
    Moderator
    • Topics: 68
    • Replies: 2574

    1000 grit stone is IMO one of the finishing stones.  I don’t consider it able to remove much metal.  More it’s to smooth metal and remove previous scratches.  To do a quick light touch-up.

    If I understand what you wrote, you only used the 1000 grit stone?  If that is the case, the 1000 grit isn’t real effective for profiling.  Therefore it wouldn’t help you even out the uneven bevels without a lot of work over a long time.  The profile, (i.e., shaping the bevels) and evening out their heights and evenness is done with lower grit, coarser stones.

    The resulting edge, working through the stone progression from coarse to fine, should improve with proper technique.

    Finally, stropping the edge at the end really improves it’s paper cutting ability and removes the snags.

    (EDIT): This I added later.  You may have a plan when your starting, that maybe you can begin with a fine grit and thinking it may only require a touch-up.  You need to be prepared to adapt.  If you don’t get the expected results.  Then I’d start stepping back down to coarser grits, stone and by stone and grit till you start to get the results wanted.  At that point start the progression back up the grits to finishing stones.

    Marc
    (MarcH's Rack-Its)

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    #44723
    graphite
    Participant
    • Topics: 10
    • Replies: 101

    Marc, the advice earlier in the thread, ignoring the trizact and angle cube sidebars, was start with my finest and work backward to coarser only if needed. Recall the edge on this knife is very thin, with such a small bevel (a few thousandths) it needs a microscope to see it.  Using a microscope along with the 1000 grit looked to be removing sufficient metal (very little to remove) so I didn’t back up to coarser grits. Just guessing, I did about 40-50 strokes per side, in groups of about 5-10 per side then switching sides. The edge cuts paper cleanly once it’s started, and cuts food (just used it for very thin slices off an onion half) so it’s close, but not quite there yet.

    I know the paper swipe cut test isn’t really a practical test, but it seems to correlate well with good performance cutting food, and you don’t waste food in the process.

    One of my questions, given 1000 grit is the finest stone I have (and I don’t have strops or pastes) is whether there is a particular finishing sequence to follow if 1000 grit is as fine as you’re going. Like 2 light passes heel to tip each side, or whatever?

    My other question is about my left to right bevel imbalance, which I’ve seen on several knives.

    PS just got a 2-axis cube (the DXL360s) but that’s a discussion for a different thread.

    #44725
    MarcH
    Moderator
    • Topics: 68
    • Replies: 2574

    Graphite, uneven bevels side to side is a reason to work backwards to a lower grit.  To even them out is to remove more metal.  But the way you’re describing it, you’re OK with the performance, how it is now.  That suggest to just live with uneven bevels, on a knife that you like the way it cuts.  The bevels are aesthetic and only you know they’re uneven through inspection with a microscope.  You did say the bevel is very tiny, a few thousandths.

    Most,  knives in my experience have uneven bevels.  Only higher end knives that are intentionally made with a great deal of attention to detail will have close or even bevels.  Or knives sharpened and corrected by a conscientious knife sharpener.

    I start every grit with single sided scrubbing strokes to establish the shape and size bevel I’m lookin for.  I’ll do the same on the other side.  Of course I do this scrubbing in stages.  A little at a time on one side bevel.  Then switch and do a little on the other side bevel.  Then switch back again.  Trying to keep the bevel work at a balance for size and shape, and from side to side. While shaping and establishing the bevel on each individual side, I’m also trying to keep or make the two sides match and draw both to an even centered apex while avoiding drawing a burr to one side first then the other.

    I don’t count strokes or use a particular number of strokes.   I try to take notice to keep work balanced from side to side.  I use visual inspection to determine which side needs more work to even them out and work each side individual as needed while still keeping the two sides matching.

    Then after I’ve apexed the knife edge while working one side at a time, I begin bilateral, (both sides together), alternating, (left/right/left/right), edge leading strokes, from heel to tip.  I continue this stroke till my scratch pattern appears even, parallel, and consistent from heel to tip and on both sides, for the full length of the bevels.  I often work a long knife edge in portions or segments then blend the portions together at the end.  I continue this same stroke till the edge is a sharp as it feels it can get with that particular grit. Then I quit.  The way I know I’ve done enough strokes to call it quits, is when I’ve done strokes repeatedly while checking for sharpness, till I determine that more strokes is not changing/improving the sharp feel.  There is no special stroke or combination of strokes to finish the grit.   In most situations I take my diamond stone progression to 1500 grit.  Particularly when I’m sharpening knives for others that are for every day use.

    To finish the sharpening job, I set the edge with strops.  Again for these everyday use knives, I’ll strop at 4µ, followed by 2µ, cow leather strops, at 1-1/2º less angle then I sharpened the knife.  This is all bilateral, alternating, edge trailing strokes.  I use the spray diamond emulsion compound.  I spritz the dry strop with rubbing alcohol prior to stropping the knife edge.

    I am using the DXL360S, angle cube.  I check and adjust all my stone angles at the beginning of each grit change.  I adjust each grit as close to my sharpening angle as I can get it, within 0.01- 0.02º.

     

    Marc
    (MarcH's Rack-Its)

    #44727
    graphite
    Participant
    • Topics: 10
    • Replies: 101

    Thanks Marc. When you say “edge leading strokes” does that mean up-strokes (spine to edge direction) or down-strokes (edge to spine direction). That terminology just seems more intuitive to me. “edge leading” seems better suited terminology to sharpening where you move the knife against stationary stones.

    When you do initial scrubbing strokes, are you scrubbing with a good bit of diagonal motion so you aren’t really hitting the same point on the knife with more than about 2 scrubs as you move down the knife with the scrubbing motion. Or are you doing a lot more scrub strokes than that, where you dwell at one point on the knife for several strokes and then moving down maybe half the width of the stone (so there’s overlap) and repeat over the length.

    PS, when I say the edge is OK, I mean acceptable; better than awful. I’m expecting to get way better than OK/acceptable edges.

    #44729
    graphite
    Participant
    • Topics: 10
    • Replies: 101

    On using the microscope with every sharpening, do you guys with significant WE experience feel that if your microscope broke, you’d probably get mediocre (or at least, less consistently excellent) results without it? In other words, do you consider the microscope a truly essential part of your process toward getting excellent not just OK results?

     

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    #44731
    MarcH
    Moderator
    • Topics: 68
    • Replies: 2574

    Edge leading is down and onto the clamped knife meeting the edge first. It is the same analogy as with free hand stones just now the knife is clamped stationary and your moving the stone down onto the edge.

    Edge trailing is up and off from the heel or spine up towards the tip then off.

    The scrubbing is a utility stroke both up and down over and over the same place then slightly, moved down, and then done similarly to another section, then spread out and blended together at the end, using overlapping strokes.  The stroke direction I use is mostly perpendicular to the edge.  Not diagonal. The purpose is to get the bevels, both sides, uniform shaped and  similarly sized, (along the one side and side to side also).  I’m trying to lay down even spaced parallel scratches of the same size and depth along both sides bevels, while creating even size and shaped bevels.

    It’s hard to get a good even sharp edge only using one grit on a never sharpened knife.  If you were doing a touch-up of a knife you had previously sharpened with the full progression then I guess a one stone one grit touch-up might bring back the initial sharpness.  But in your situation who knows what you had to start with.  You took a guess based on how it looked under a microscope.

    You’re getting what you got because you chose to work with it.  You probably could keep at it with the 1000 grit and improve the sharpness by doing more strokes. But it’s hard to do that while not changing the tiny bevels you wanted to keep that way.

    To get better than acceptable edges you’ll need to sharpen that knife.

    For me the microscope is now an essential tool.  But since gaining experience while using it.  I believe I know how to get just as sharp results with out it.

    Marc
    (MarcH's Rack-Its)

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