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Mike L.
10-26-2012, 04:55 PM
Convex grinds and convex edges are very popular on sporting and defensive knives. Anyone tried/use them on kitchen knives?
Hope I am not suggesting heresy. :eyebrow:

James
10-26-2012, 05:32 PM
I think a lot/most knives have some degree of convexing; a convex grind helps mitigate stiction problems. I'm not sure about convex edges.

Pensacola Tiger
10-26-2012, 05:35 PM
Nope, no heresy.

Convex edges were used by Bark River on their kitchen series. For most people, it's easier to maintain a 'v' edge on waterstones rather than mess with sandpaper and mousepads or the expense and requirements of a belt grinder.

Note that the practice of adding a microbevel is essentially approximating a convex edge.

Rick

stevenStefano
10-26-2012, 05:35 PM
Its a pretty complex subject but you are true that it works well with kitchen knives and most good knifes will have a convex grind.

WillC
10-26-2012, 05:49 PM
Convex faces yes. Final bevels on very thin edges are much more practical as flat surfaces, and I think they cut better with less resistance. I tried very thin edges with convex final edges on my first few knives and it makes them a pain to maintain. On a thicker blade I say it can work, a convex on a cleaver works well, it does offer more support to the edge. But on uber thin edges I don't think the increase in support is noticeable and cutting resistance is increased as well as sharpening time.

Dave Martell
10-26-2012, 05:59 PM
Convex faces yes. Final bevels on very thin edges are much more practical as flat surfaces, and I think they cut better with less resistance. I tried very thin edges with convex final edges on my first few knives and it makes them a pain to maintain. On a thicker blade I say it can work, a convex on a cleaver works well, it does offer more support to the edge. But on uber thin edges I don't think the increase in support is noticeable and cutting resistance is increased as well as sharpening time.


A BIG :plus1: from me on this one.

Dave Martell
10-26-2012, 06:01 PM
Convex edges will happen even if we don't want them to and that's just from our natural wobble while sharpening. I say try for a flat bevel and you'll be better off than trying to convex and getting a thick edge in the process.

VoodooMajik
10-26-2012, 06:17 PM
I thought blending the bevel into the blade face was a form of convex edge? Am I mistaken?

tk59
10-26-2012, 06:58 PM
No. But the bigger the bevel, the more it contributes to the overall characterstics of the blade. A tiny bevel blended into a blade face isn't going to make as big a difference as a large one.

knyfeknerd
10-26-2012, 07:18 PM
Nice thread Pops!

Mike L.
10-26-2012, 07:50 PM
I've been using a olde very cheap carbon chef knife with a convex edge formed on a sandpaper over mousepad gadget. Using only 400 grit paper it produces a powerful slicing edge. But, I'm a home cook who usually only prepares meals for myself. So, it doesn't have to last long until the next sharpening. I'm aware that this would never do in the Professional world.
No pics, because the knife is so horrible that I don't want to embarrass Knyfeknerd or even myself! :knife:

Benuser
10-26-2012, 08:32 PM
Refine with finer sandpaper and the edge will last much longer. You may even consider stropping on leather or newspaper.

EdipisReks
10-26-2012, 08:52 PM
Convex faces yes. Final bevels on very thin edges are much more practical as flat surfaces, and I think they cut better with less resistance. I tried very thin edges with convex final edges on my first few knives and it makes them a pain to maintain. On a thicker blade I say it can work, a convex on a cleaver works well, it does offer more support to the edge. But on uber thin edges I don't think the increase in support is noticeable and cutting resistance is increased as well as sharpening time.

right here is exactly how i do my gyutos.

keithsaltydog
10-27-2012, 06:25 PM
I thought blending the bevel into the blade face was a form of convex edge? Am I mistaken?

I would agree,blending bevels,which can only be done freehand can form a convex type edge.I call it back bevel & final bevel.The main thing & a mistake often made by begining sharpeners is rounding the edge.You want the two plains of your final bevel to meet to molecular infinity.

Lifting the spine at the end of a stroke either on a stone or strop can round your edge.Too high angles on a steel or over aggressive burr removal on the stone same thing.Thinning behind the edge,creating burrs,even if very fine burrs on polishing stones ending wt. lite strokes,to plains of bevel must meet.Cleaning up that edge,even newspaper works well.Main thing do not undo the edge wt. poor tech.

VoodooMajik
10-28-2012, 03:44 PM
That's basically how I'm been working my Yoshihiro.

I've been thinning it up behind the edge at a fairly low angle forming a bevel above the edge, then I sharpen up the bevel on my cutting edge. Afterwords I have been blending them together and into the blade face. It seems to stick less, less resistance and simply cut better.

Standard progression (10 down for carbons, 30+ down for vg10). My explanation is fairly brief but I'm sure most of you can imagine what I'm up to. Is There anything I should watch for apart from not rollling/roundng the edge? Does this just sound like bad news?

keithsaltydog
10-29-2012, 04:45 PM
If it works for you who is to argue.I don't even out the two bevels,but looking wt. a loop they are blended not distinct.Like to polish in progression all the way back to the rear of back bevel,this works well,giving less resistance going through food.

I am finding in teaching culinary students & cooks in the buss. that rounding is common.Thanks to Dave's DVD I am better able to draw pictures & explain what works & why.