Convex vs. Scandi vs. Flat (lesson of different grinds)

[@jeffsmith6441]

Very good explanation! You did a great job showing what you were talking about.

[@prestonscott5367]

Thanks brother, I appreciate it

[@andreasjonsson8075]

Good job dude

[@Crosswalker.]

My grandfather has a knife looking like a fishing knife, but once it was a normal kitchen knife, sharpening it for 40 years made it kind of small and pointed... 😊

[@prestonscott5367]

Those are kinda special to keep 👍

[@Crosswalker.]

They are, one has an eagle head on the handle, we played as kids cowboys and indians with it 😂

[@johnnygimms4523]

Extremely helpful explanation! Thanks for taking the time to go over this concept for beginners like me.

[@prestonscott5367]

Thanks for the comment! I only did it for y’all, God bless!

[@abstractapproach634]

It's good the way your thinking, but most people know they have to redo the secondary edge at some point. It's easier to grind ~a mm of metal many times and only have to hit the up to inches (whatever your secondary edge is, usually over a cm anyways) on some knifes once in a blue moon (most people never have to) And your picture was more true to lie than you, no-one can perfectly replicate the convex curve and it does flatten out over many sharpenings (as any part you overgrind will not be so if it became concave/"holow") *I am serious about the comment though, many people subscribe to a sharpening technique and swear by it. People will argue along vs against vs away, but with the understanding you have you get that your just grinding down material.* Well done video, even though I do not support your conclusion I enjoyed it.

[@stevestory8483]

Great explanation! Thanks for putting together

[@Bubelmanen]

This was all I needed.

[@perfumer8549]

great info but bow to sharpen a convex

[@JoshBenware]

Hey preston. I just want to say I'm sorry to hear about your loss. I wasnt watching the side chat too much and didnt realize until going back and seeing it. Hope your doing ok.

[@prestonscott5367]

I never saw this comment before josh.. but the se e it now, I still appreciate it... it’s been taking me a long time to let go of him 😥

[@vinnym5095]

How do you sharpen a scandi grind? Are you able to visually determine the grind just by looking at the knife? I can’t tell

[@amacrotte]

Just lay the bevel flat on the stone. You feel it lock in.

[@scottf.3808]

Very nice detailed info as I learned alot there....I think the vid might have been cut short.....Good stuff....

[@prestonscott5367]

Thanks Scott F. The video was cut short, but it’s okay. I didn’t want to redo it

[@sabelfechter7136]

So correct and so utterly dumb at the same time. I highly prefer convex, but this is a apples to oranges comperasion, and highly misleading. If you remove metal on the entire side of the blade for convex and shorten the parallel portion, you can do the exact thing with the flat grind in the same time. Thinning the flat makes the V edge thinner again... I prefer using convex blending between a 15° 0.1mm long edge and a full flat grind. That gives me an extremy fast to touch up and consistant edge, but the smooth transition of a convex. Instead of the large V edge shoulders. I do that instead because i hate thinning the entire flat grind per hand, and with my 0.1mm edge it would be too weak anyways.

[@prestonscott5367]

You’re very correct. Reason I didn’t mention that though is because usually flat grind knives have nicely finished blades weather satin or stonewashed and grinding such a lard surface area on stones is soo difficult...... so nobody touches that typically. So I wouldn’t call it completely utterly dumb.... and buddy, almost everything in life is apples to oranges. Let’s not be butt hurt about it. We’re discussing DIFFERENT kinds of edges. (Apple to oranges to pears) to see to learn about their differences. Not discussing how the same thing is done different ways (apples to apples) good day.

[@sabelfechter7136]

@@prestonscott5367 Sry for this use of words, i should have worded that better. And i kinda agree, i hate thinning. But there is no difference in time to thin convex vs flat. Its just a percived difference. Also sure were "just comparing grinds" but you made a cherry picking argument without even mentioning the same can be done with the flat grind, this video misinforms people. I know you dont "have to" mention it, totally fine, but that makes the video pointless. And hey i prefer convex above anything else. Its so good due to its smooth transition of two angles like 15° into 2°, and lack of shoulder. It doesnt even need any more cerry picking arguments to make it seem better, it already is. Its not meant against you in the slightest. Its just that thinning always requires the same time. And to be overly precise, actually... there is more surface area on the convex therefore more steel to remove :P (I still like it more ofcourse) Where in my opinion the convex is way faster in thinning is if your in a hurry/or cant be bothered and just thin like the first centimeter from the edge. Because while thats not perfect, its where it really matters most afterall. And you cant do the same thing with a flat grind. If you lay it on the stone, even if you put more force of towards the edge, so it thins it faster but doesnt touches the parallel section of the blade - more metal needs to be removed to have a thin shoulder, and have a straight line between the two points. The only way to thin this important section faster on a flat grind would be a relief bevel at a degree between the flat grind 2-3° and edge 15°. Like lets say 8°. So basically a convex all over again but with too large facetts and therefore worse performance. Thats what i highly prefer about thinning a convex, its faster to thin where it matters most.

[@prestonscott5367]

@@sabelfechter7136 good informative comment. This video is also kinda old, it’s just my perception in this video that’s responsible for the perceived cherry picking 😅 and it’s also hard to think of everything single way to think of this subject on my own... it’s too difficult to articulate some of the things I mean without talking in person or making further videos on the subject...

[@prestonscott5367]

Your points are valid though, thanks for the comments, God Bless. (Shoot me a link if you make or have a video on this subject)

[@sabelfechter7136]

@@prestonscott5367 Great video still! And well drawn. Shows how V edges thicken up and cut horrible. But people dont notice the difference because it happens over a long time. Thats actually a good idea. Far back when i started YT i was in the knive community and even had a channel, totally forgot about that! But for me the problem was i felt pressured making videos, so it got less fun and i stopped. Now im a lot different and could start again! Btw, what Apex angle do you use on your knives? 10-12.5-15-17.5-20° etc? I thought about sharpening a friends kitchen knive, i usually use 15° which tends to be the most agreed upon. And its true that lower angles retain sharpness longer - but, thats against abrasive material like cardboard or rope. Against abrasion it takes longer for the Apex to be thickend. What i worry much more about is the impact on the wood/plastic cuttingboard. Whats your thought?

[@EinsPerson]

Great video! This is the best explanation i have found on KZbin so far. I experimented with convex and scandi grinds on budget knifes myself and found that thin convex blades are perfect for Fethersticks and thick scandi grinds are good for wood splitting. I also found that by decreasing the angle of a scandi grind the blade cuts better and splits only slightly less good. Seams obvious i know, but it can make a great improvement for your Fetherstick performance.

[@prestonscott5367]

Good notes 👍 take care, thanks for the comment

[@itechhen]

You don't put a micro bevel on a hollow grind. But I really liked where this was going. Yet another area you did not address is the different types of blades. For example, a flat blade which the unsharpened area is most of it. In this case you could maintain a Scandinavian grind the entire life of the blade. In all of your examples, the unsharpened portion is minimal.

[@Just_a_Tool]

So why can't a full flat grind have a zero grind with just the primary bevel?