how to make a western style chinease steel knife convexed

[boblob]

i have a western style knife that was made by ikea that i want to make convexed i have a few questions regarding that
1. why would you want to make the edge convexed ? from what i saw after thinning the edge and adding the convexity it helps with wedging
2. what is the order you do things ?
those are the steps i want to make but in what order do i do it ?
thinn the knife
add the convextion
sharpen the primary edge in order to apex the knife and make it sharp
maybe add a small micro bevel
3. i saw mr carter showing how to add convexity by first sharpening near the primary edge and then lowering the angle more and more making the convection by sections in contrast to what i saw mr @JBroida doing when he was sharpening a yanagiba using the hagamuri method ( he was sharpening near the shinogi and raising the knife angle by sections and reaching the primary edge)
do i do it like mr carter or like john ? (starting at the lowest angle and raising the angle or starting at the highest angle and then lowering the angle ?)
4. lets say the knifes current primery edge sharpening angle is z do i go higher than z when doing the convexing part ? if yes then by how much ?
should i add a micro bevel ? a few feather light edge leading storkes at a higher angle after finishing the deburr will do to create a micro bevel ?

 

[HumbleHomeCook]

Okay, not trying to be a jerk, but you really need to understand the "why" of something to understand the "how" of something. You're very focused on the how and that, in my opinion, is making it harder for you to understand the approach.

Convexing is just adding a curve to each side of the knife.

Lay the knife flat on a stone and imagine how you would add the curve. Visualize it and where it would go and that will immediately start helping you understand how to execute it.

That said, I suspect trying to convex an Ikea would suck and I wouldn't bother. If the knife is pretty thin you're not going to gain a whole anyway because you only have so much material to work with.

Convexing is not a magic that fixes myriad issues. For my uses, I generally do not convex my blades beyond whatever may have been there originally. You convex mainly to add strength.

If you're having some wedging issues, start by just trying to thin/smooth the shoulders of the edge bevel.

 

[boblob]

Okay, not trying to be a jerk, but you really need to understand the "why" of something to understand the "how" of something. You're very focused on the how and that, in my opinion, is making it harder for you to understand the approach.

Convexing is just adding a curve to each side of the knife.

Lay the knife flat on a stone and imagine how you would add the curve. Visualize it and where it would go and that will immediately start helping you understand how to execute it.

That said, I suspect trying to convex an Ikea would suck and I wouldn't bother. If the knife is pretty thin you're not going to gain a whole anyway because you only have so much material to work with.

Convexing is not a magic that fixes myriad issues. For my uses, I generally do not convex my blades beyond whatever may have been there originally. You convex mainly to add strength.

If you're having some wedging issues, start by just trying to thin/smooth the shoulders of the edge bevel.

i thin this knife every time that i sharpen it like mr @stringer

 

[D J]

With time and practice you will get a better understanding. It's good to have people who can give you advice, but unless you have someone there with you to give instructions. Ultimately we must teach ourselves, in the beginning sharpening is a mystery to us, there are a lot of different ways and views of what is the right way. It's very easy to become confused. Just stick with it, you'll get there. Or you could get someone to sharpen it for you. When I look back at the journey, and what I tried and failed. The mystery and confusion. I wouldn't change a thing. Learn from your mistakes ! Good luck bud

 

[Nemo]

There are two things that you could mean by "convexing":

1) Convexing the edge (changing the edge bevel from straight to convex). Adds some strength, slightly reduces sharpness. Not much work.

2) Convexing the whole (or at least the lower half of) the blade. Often improves food release but worsens wedging. A LOT of work.

Which of these do you mean?

I'm also a bit confused about what you mean by a "Western style Chinease steel" knife from Ikea. Do you have a picture?

 

[D J]

I just thought the same thing after I posted

There are two things that you could mean by "convexing":

1) Convexing the edge (changing the edge bevel from straight to convex). Adds some strength, slightly reduces sharpness. Not much work.

2) Convexing the whole (or at least the lower half of) the blade. Often improves food release but worsens wedging. A LOT of work.

Which of these do you mean?

I'm also a bit confused about what you mean by a "Western style Chinease steel" knife from Ikea. Do you have a picture?

 

[boblob]

1) Convexing the edge (changing the edge bevel from straight to convex). Adds some strength, slightly reduces sharpness. Not much work.

how do you convex the secondary bevel ??

2) Convexing the whole (or at least the lower half of) the blade. Often improves food release but worsens wedging. A LOT of work.

hmm very interesting why does it make the knife wedge more ? seems like its not the thing for me or this knife because altough everytime i sharpen it i thinn it on a coarse stone for a long time it still wedges on tougher food like sweet potatoes and such .....

Which of these do you mean?

i meant the convexing of the secondary bevel but thank you for explaining me on the convexing of the primary grind also

I'm also a bit confused about what you mean by a "Western style Chinease steel" knife from Ikea. Do you have a picture?

here is a photo of the knife

https://www.ikeaddict.com/ikeapedia/en/Product/90134953-3/us-en/gynnsam-chefs-knife-dark-gray/Entry/

 

[Nemo]

One should be careful about the terms "primary" and "secondary" in relation to "bevel". Some people think the primary bevel is the edge bevel, others think it's the relief (or thinning) bevel.

Better to use the terms "edge" and "releif".

To convex the edge bevel, start grinding at an angle much lower than the edge angle and gradually raise the spine until you hit the edge. Voila, convexed edge. The downside is that it can be difficult to control (or replicate) the exact edge angle.

My comment on convexity and wedging is poorly worded. Convexing (the whole blade) doesn't actually make the blade wedge more per se, but it does require the blade to be thicker and this requirement does increase wedging somewhat. So convexing your blade wouldn't make it wedge more, but could only be done in a knife thick enough to accommodate the convexity (and therefore potentially increasing wedging vs a a thin grind). See @Kippington 's excellent thread "A basic explanation of assymetry" for an explanation of why.

 

[stringer]

Film yourself sharpening. Post it on here. Show us pics of your actual knife that you have done work on. Only way you will get better. You can only get so far watching others videos and reading others words. You need practice and you need someone who knows what they are doing watching you practice and critiquing your work. This isn't a problem with an easy large language model solution.

 

[boblob]

To convex the edge bevel, start grinding at an angle much lower than the edge angle and gradually raise the spine until you hit the edge. Voila, convexed edge. The downside is that it can be difficult to control (or replicate) the exact edge angle.

why not go a little bit over the edge angle like when doing a micro bevel ?

 

[boblob]

Film yourself sharpening. Post it on here. Show us pics of your actual knife that you have done work on. Only way you will get better. You can only get so far watching others videos and reading others words. You need practice and you need someone who knows what they are doing watching you practice and critiquing your work. This isn't a problem with an easy large language model solution.

dont have a camera

 

[Jae1L]

I might be completely off, but do you mean convex grind?

I don't think you want a convex edge but rather a convex grind to improve the food release, and cheap knives have flat grinds which have bad food release.

In my opinion, those knives are 55hrc which really can't support thin edge anyway when you make convex grind after thinning

 

[ThirdJewel]

dont have a camera

Cell phone camera?

 

[boblob]

Cell phone camera?

do not have it

 

[boblob]

I don't think you want a convex edge but rather a convex grind to improve the food release, and cheap knives have flat grinds which have bad food release.

when cutting tomatoes and high water content food it sticks like a magnet to the sides its because of the flat grind ?

I don't think you want a convex edge but rather a convex grind to improve the food release, and cheap knives have flat grinds which have bad food release.

i was actually asking about convxing the edge (in this photo the secondary edge) instead of adding a micro bevel in order for me to able to sharpen the knife at a lower angle and for the edge to hold

 

[Jae1L]

when cutting tomatoes and high water content food it sticks like a magnet to the sides its because of the flat grind ?



i was actually asking about convxing the edge (in this photo the secondary edge) instead of adding a micro bevel in order for me to able to sharpen the knife at a lower angle and for the edge to hold
View attachment 246318

Well, use a honing steel. That's the best advice I can give. Those knives are made with the thought of using honing steel.

I don't think you will not see much benefit, and it's hard to do even convex edge with whetstone.

If you have the money to buy a sharpening system to do convex edge I would bet a better knife.

 

[stringer]

dont have a camera

I can't see what you're doing wrong or right without seeing what you're doing.

 

[boblob]

I can't see what you're doing wrong or right without seeing what you're doing.

i am not asking what am i doing wrong or right i am asking about the theory of sharpening

 

[boblob]

Well, use a honing steel. That's the best advice I can give. Those knives are made with the thought of using honing steel.

i use a dickoron micro

 

[stringer]

i am not asking what am i doing wrong or right i am asking about the theory of sharpening

Attempting to learn sharpening by understanding the theory is like trying to learn to ride a bike by studying physics.

 

[boblob]

Attempting to learn sharpening by understanding the theory is like trying to learn to ride a bike by studying physics.

i practice physically....
but must understand the concepts also

 

[tostadas]

If you're doing on stones by hand, you can start off just trying to do it flat. Look to get an even and consistent scratch pattern off of each stone. Combination of non perfect stones, and some natural inconsistencies of doing by hand, the result will likely have at least some convexity. See how that goes first, then once you get that basic grind down, then you can play with adjustments to do a more complex geometry.

Jon broida and Murray Carter videos cover the basics. I think those should set you up once you're ready.

 

[M1k3]

 

[boblob]

already seen mr cater

 

[boblob]

If you're doing on stones by hand, you can start off just trying to do it flat. Look to get an even and consistent scratch pattern off of each stone. Combination of non perfect stones, and some natural inconsistencies of doing by hand, the result will likely have at least some convexity. See how that goes first, then once you get that basic grind down, then you can play with adjustments to do a more complex geometry.

already have the basics down