Mirror Polished Edge

[ricklee4570]

Is there any real practical advantage to polishing the edge to a mirror finish?

I know it is a matter of pride. It is fun. And it is freaking awesome to show off. But in reality, does it actually help as far as the practical cutting ability of the knife in real world applications?

Where would the polished edge actually be beneficial and to what degree?

 

[Noctis3880]

I would say it's best for the kitchen, and the difference is like night and day. Most people insist that I need a "toothy" or serrated blade to cut tomatoes and raw meat, but I break all the rules and cut my steak with a hair popping plain edge. It's hard for an observer to tell the difference, but if you've ever tried cutting the fat out of your steak, you'll KNOW the difference.

Also, that's probably the only type of cutting that won't instantly roll the extremely thin edge over since the medium is so soft.

 

[changeofseasons]

I agree with noctis. Cutting raw meat and slick veg is how I judge the usefulness of a particular edge. I've found that coarser edges tend to catch and tear silver skin rather than cut it cleanly. A coarse edge tends to dull more quickly as well. You don't need a perfect mirror to cut well. But it is my opinion that not completely finishing the edge is sloppy and unprofessional.

 

[Kbrasmodeler]

I sharpen most of my knives to a mirror polished convex edge. I cut rope, cardboard, whittle wood, carve, slice fruit, meat, veggies and bread, open packages, etc...
I find the convex mirror edge works better, and lasts longer, on all of these tasks. I don't have any more problem with edge retention or rolling/chipping/wearing than I did with toothier eges, and, in fact the edges seem to last longer. And BOY does it cut!

 

[unky_gumbi]

I am no expert, but I find that a polished edge slices smoother and last longer then a toothy edge. What it really comes down to is preference though, if you are on the fence try both toothy and polished and see what you like and suits your needs better.

 

[ricklee4570]

I have read where a polished edge won't cleanly slice a tomato, instead squashing it. I may have to polish some edges and see for myself.

Ben Dale of Edge Pro Sharpeners says not to polish kitchen knives. Interesting difference of opinions.

 

[changeofseasons]

I have read where a polished edge won't cleanly slice a tomato, instead squashing it. I may have to polish some edges and see for myself.

Ben Dale of Edge Pro Sharpeners says not to polish kitchen knives. Interesting difference of opinions.

It's true that you just need to try it. A knife's ability to cleanly slice a tomato is not hampered by having a polished edge. That being said, I have seen knives with polished edges not cut a tomato well. That has to do with other factors... i.e. improperly aligned edge, rounded edge, etc. I've sharpened my Japanese knives with an Edge Pro, polished the edge with 0.25 micron diamond on leather, and they can still drop through a ripe tomato months after being sharpened.

 

[unky_gumbi]

Yeah, I have never had a problem slicing a ripe tomato with a polished edge either It could just be that my polished edge isn't all that polished though, but it sure looks like it under a 10x loupe

 

[stitchawl]

I have read where a polished edge won't cleanly slice a tomato, instead squashing it. I may have to polish some edges and see for myself.

Ben Dale of Edge Pro Sharpeners says not to polish kitchen knives. Interesting difference of opinions.

I'm with Ben on this one. :thumbup:
I love a highly polished edge on my EDC and my hunting knives, but not on my kitchen knives. This does NOT mean I don't want them very sharp. I want them to be very sharp, especially my chef's knife and my carver, but I want my paring knife to have a toothier edge. There is no middle ground with a tomato. The knife either has to be very, very sharp, or it has to have some tooth. This is why so many people found the cheap Ginsu knives to work so well for them. They aren't sharp, but they have a micro-serrated edge that can cut through just about anything.

Stitchawl

 

[pwet]

I There is no middle ground with a tomato. The knife either has to be very, very sharp, or it has to have some tooth.

Stitchawl

sounds like you dissociate sharpness and polish ? and edge should be sharp no matter the level of polish. and from my experience as long as the edge is properly formed there's no grit that will fail cutting a tomato. it just won't do it the same way. at 600 grit you'll have to use light pressure and a slicing motion while a 10k polished edge will both push cut and slice probably not as agressively but it will . those are the extreme but every part of the grit range between those two points will work.

there's just a very significant difference if you are doing this for a living, vegetables and fruits cut with a polished blade holds up waaaay longer than the same prep cut with a rough edge. try finely slicing a few basil leaves with two different blades and let it rest in a closed box with a piece of moist paper towel. one will turn black 3 times faster than the other.

other than the conservation issue it's all personnal preference from the way you use your knife.

 

[stitchawl]

sounds like you dissociate sharpness and polish ?

That's right. I do. They 'can' both be found, or they can be one or the other. It's up to the sharpener. We can put a very high mirror finish on a dull knife, or put a toothed edge on a well polished knife edge. A Ginsu isn't sharp, but if you slice with it it works very well in the home kitchen.

and from my experience as long as the edge is properly formed there's no grit that will fail cutting a tomato. it just won't do it the same way.

Your last sentence is the key. Of course it won't do it the same way. But then if you change your method of cutting, you aren't making a valid comparison. You are changing the ground rules. And in this case, the OP was asking about how to sharpen, not how to cut.

it's all personnal preference from the way you use your knife.

That's right.

The OP said that he wasn't getting a good cut on tomatoes. I'm not about to tell someone how to change their style of cutting when their question was about sharpening. I'll tell them how to adjust their sharpening to match their method of cutting. It seems to make more sense to me that way.

Stitchawl