Argument against flat grinds

H

Houlahound

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Aug 2, 2017
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As my purchasing choices reflect a growing preference for fuller, thinner flat grinds and a rabid cult-like obsession with thicknesses behind the edge, this pops up in my feed.

Does his logic become less valid in the current age of super-steels we live in?

Also is this guy a member?


 
1) Mike Stewart knows what color my checks are, so I might not be totally objective.

2) Sorry, I don't even know what a carbide is.

3) Even if you buy a full flat grind, what's it going to be after the first time you sharpen it?

4) I'm okay with my Bark River knives. When the most recent one arrived last week, pieces of paper got up and ran out of the room.

5) I have an idea that I want my Spyderco knives to be flatties. We'll have to see. Should we be talking about the knife as well as the grind?

6) There was something else, but I can't remember now.
 
There is nothing wrong with convex grinds for certain uses. Yes, they typically hold an edge well when used for harder tasks. BUT.....

I do not agree with Mike saying they are "better" than a full flat grind. That is ridiculous. It depends what you are cutting. If you are doing general knife cutting stuff, or food prep, or heck - just whittling, you aren't going to find a better grind than FF (or arguably hollow ground). To say otherwise just shows either ignorance, or the total lack of desire to offer blades with more than one grind option.

I want my axe to be convex - but I have never in 50 years of owning a knife said "Jeez, this would cut a lot better if it was convex." Never. NEVER.
 
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Mister Coffee said:
6) I just remembered. There's a guy on YouTube. His channel is "Whittlin' Time" or something corny like that. Half the time, he plays up the good ol' boy thing, and half the time he makes fun of it. In reality, he's a smart guy. Anyway, he's a knife maker, and he prefers flat grinds. Mostly for the reasons shane45-1911 shane45-1911 stated. Hey, if you need an axe, get an axe.
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You mean William Collins?
 
Are we talking blade geometry or edge geometry? My experience is convex edge geometry is stronger than a V edge. V and convex edge will perform different and that could be good or bad depending on media. A saber grind blade geometry will batton wood better than a FFG due to better splitting wedge shape. FFG is better at slicing through media with less resistance when the media is wider than blade width IE cardboard
 
Interesting topic. Please stay on it so I don't have to close the thread.

I do not care about your opinions of Mike Stewart as a person. I do care about your opinions about his opinions on knife grinds.
 
shane45-1911 said:
I do not agree with Mike saying they are "better" than a full flat grind. That is ridiculous. I
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He didn't say "better." He said an FFG won't hold an edge. No support for the carbides. And, since I think F Fir Na Tine raised the issue, Mike said all Barkies are flat grinds. Then, they're conexed. Then, the convex is blended. Several of virtuovice's YouTube videos are complaints about "microbevels" on Bark River knives from the factory, and Mike says he doesn't put a microbevel on a finished knife, so now I'm wondering if virtuovice got a few that just weren't fully blended.
 
That video is ridiculous, full flat grinds are fine and hold carbide no different than a convex edge.

“Those edges feel sharper; they’re not”

I don’t even know how to respond to such nonsense. That’s like ordering a bowl of soup at a restaurant and the waiter tells you “it may look like soup, but it’s actually a sandwich”.
 
The Aflac Duck The Aflac Duck : I've had that soup. Sometimes, I feel a knife, and it seems dull, but when I cut with it, it's not dull.

If the issue has to do with carbides, then shouldn't we be talking about the steels as well as the grinds?

Sorry to be asking questions, but I'm not an expert, so I don't have any answers. :D
 
Mister Coffee said:
The Aflac Duck The Aflac Duck : I've had that soup. Sometimes, I feel a knife, and it seems dull, but when I cut with it, it's not dull.

If the issue has to do with carbides, then shouldn't we be talking about the steels as well as the grinds?

Sorry to be asking questions, but I'm not an expert, so I don't have any answers. :D
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Maybe ask Sandrin, since they make blades completely out of carbide and don’t use convex edges. Mine holds an incredible edge.
 
I have only owned two bark rivers and I don't have them anymore, so I can't check them out. However, lets say you take a 1/4" thick, 2 inch wide blade and give it a full flat grind, then convex the edge. The only way to make that blade a full convex is to grind away a large amount of material from the edge. A flat ground blade is not as thick in any part of it's cross section as a convex blade. So that same blade might lose half an inch or more of it's width and it will lose the original edge. New edge would need to be put on it. Not sure why anyone would do that. But I am not a knife maker so....I guess I am missing something here.
 
1. Wow already a thread warning - There must be some Mikey stuff I must now investigate.

2. Edge - if you have sharpened your knife - it’s flat. I’m not sure how you could get anything but flat. The edge itself is like 1/100” of an inch . I’ve never heard anyone say I sharpened it 20 degree preside convex.

3. Blade grinds - yeah that makes a difference how goes through stuff. What’s better? all depends on how thick the stock is.

full height is nice - sometime only a saber grind is needed. Dragonfly 2 is one of my favorite full heigh as well as the FHFH ratmandu.
 
Grinding Convex (and other) blades


edit: from this video I get the impression that FFG and convex grinds are only minimally different.
Many (most?) Bark Rivers are not full convex and it seems that when Mike says all their knives start out as FFG it means they are not to zero, but quite the opposite, more likely they are still very thick behind the edge, so there is enough material left for convexing without grinding away the material where the apex should be (iow, where the apex will be formed).
 
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Houlahound said:
The apostle P talking about the superiority of the convex grind over the flat using a Bark River knife as an example.

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Good video and I agree with what I saw in the first 6 minutes and I agree that convex has many advantages both as an edge and a full blade grind.

I think the argument being made, is whether a. the edge carbide stability and strength is in fact better with a convex, and b. if the edge will in fact last longer than a v-edge and c. if it is in fact sharper than a v-edge even though the v-edge feels sharper. The answer to A is always yes, because there is more material. However, unless you are taking the V-edge down to super thin levels, the v-edge stability will be good for all reasons and I don't believe convex has an advantage in B and I am sure the v-edge is sharper. I can take a v-edge down to crazy thin levels of sharpness. Convex by it's very nature cannot ever come close to the initial angle of a V-edge. However, a convex has no sharp transitions to increase resistance like a v-edge does, so what Mike is saying has some logic behind it. I guaranty that this has been discussed in the past with arguments on both sides. This is all just IMO

So, IMO, the real question that needs to be answered is if, in modern cpm3v and A2, (which is what bark river uses) whether there is a big difference in edge carbide stability for these steels in convex or v-edge mode. Where are our Forum Metallurgists for the answer? :D It's easier to have them answer than to have our lazy asses use the search function to find it, as I am sure this has all been discussed before.
 
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