Why are burrs so malleable?

[grepper]

You are spot on in every respect Mr. Mark.  If we all do our part and recognize the benefits of a well ordered and searchable forum we will make the Exchange a much more useful and valuable resource for all of our benefit.

One easy way to make this happen is when the opportunity to start a new thread presents itself, simply start a new thread and note in the original thread that you are taking up the conversation in a new post.  And, yes, posts can easily be moved to a new thread/forum if necessary.

Especially as the Exchange grows, it become increasingly difficult to keep up with every post in every thread, making for a daunting moderator task to keep things well organized.  

If we all participate in keeping the Exchange well organized, the problem will resolve itself effortlessly with minimal moderator intervention.

[Bud]

I received a very nice looking Japanese made kitchen knife for Christmas and have just gotten around to messing with it. Came in a beautiful box. The paperwork with it said it was HRC62. I expected this thing to knock my socks off sharpness wise but was surprised to see that it tested over 300. I'll take their word for the fact that it is HRC62 because it took some fair grinding to raise a burr. The burr raised was this super flimsy pain in the rear like we all have seen and is talked about throughout this thread. I use a Sharp pad in cases like this and experience tells me that the quickest way to get rid of these things is to use the rubber base of the sharp pad but even that took some time and effort with this knife. The edge got sharp enough for me 185 but it makes me wonder. If the burr acts like a piece of tin foil  and the burr is attached to the edge then what makes me think that the edge is any harder than the burr? Just makes me wonder whats going on here. Also makes me wonder if we are throwing money away on these expensive knives. Pain in the rear to sharpen and a big question mark in my mind about if they are any better or not.

[grepper]

I’d be perfectly happy with a 185 edge too.  I’d say, good job!

I don’t know if the steel in a burr is harder/softer than the blade and I doubt we have the ability to determine that.  But obviously, the flimsy burr is not part of the solid structure of the blade and very weak compared to the edge beneath it.  Regardless if it is as hard as the blade itself it must be removed as it will crush, fold and bend causing the edge to dull quickly if it is not removed.

Are expensive super steel, very hard blades worth it?  I have no doubt they have better edge retention, but how much better?  Is it worth it considering they chip more easily and are more difficult to sharpen?  Maybe, maybe not.  I think that depends on how the blade is going to be used, who is sharpening it, how often it will be sharpened and other considerations as well.

“Pain in the rear to sharpen and a big question mark in my mind about if they are any better or not.”  I think only you can answer that question after using it for a while.  Maybe you may end up deciding a blade that dulls more easily but is easier to sharpen fits your needs better.  Or maybe you may find the edge chips and a more malleable steel better fits your needs.  Or, maybe you will be amazed that the thing seems to stay sharp forever and rejoice in your beautiful new knife.  I (we) will be interested in hearing what you think after you use it for a while!

How much better is the edge retention?  I think Mr. EOU is working on a way to determine that.  

[me2]

Specifically related to high hardness Japanese knives, the couple I've had are typically very thin behind the edge. I'd recommend against any power sharpening. The initial rebeveling might take a while, but after that, a visible flat on the edge can be resharpened in as few as 15 to 20 passes per side, per grit. The thin edge can thicken very quickly if large foil type burrs are raised. Hand sharpening allows enough control to form the barest minimum of a burr and avoid having to remove those large foil burrs that area so frustrating.

[Bud]

Thanks for the compliment Mr. Grepper and thanks for the advice Me2. I used to be satisfied with edges a lot duller than 185 but now I turn 185 edges out easier and faster than I did 300 edges. Wish I had the same luck with stones that you do Me2 but it just doesn't seem to be in the cards for me so far. I'm going to make another run at it because Lord knows I've got plenty of them.

[me2]

What kind do you have?

[Mark Reich]

Guys, I would love to be able to find a thread about sharpening hard Japanese steel and thin edges.

I wouldn't be looking in this thread, which has meandered through all kinds of topics.

Please don't hesitate to start new threads according to different topics!

[me2]

Ah, yes, back on topic. Sorry about that.

The foil burr is floppy and irritating because it is so thin. Even glass is floppy when in a very small diameter fiber.

[Bud]

What kind do you have?

I do have I think close to 25 or 30 different stones and many are double sided. I don't think that you would be impressed because most were picked up at farm and garage sales. I'm going to have to get the box out and look  because I think that few are labeled or marked in any way and only a couple still are in the box they came in. It's pretty obvious that they are an assortment of grits. Some are so uneven and worn that they should probably be tossed and others look as if they've hardly been used. I was just reading your's and Mark's new posts here and as a result I think that I'm getting motivated to give it another try. Too many projects. I'm determined to get the wife's ceramic kiln up and running again so I can try my hand at knives made from files. Got the wrong parts the first time and now, hopefully, I've got the right ones on order. If push comes to shove I'll just leave another ink pen in my shirt pocket and toss it in the laundry basket like I did last week. When she got the clothes out of the washer she was plenty hot enough to melt steel over that.

[Bud]

Here's a picture of the knife I was talking about. Looked it up this morning and its about a $60 dollar knife which makes it about the most expensive knife that I own. The blade is really not any thinner than a regular knife. The listing I found for it says that it's a sushi knife. It will never get used for sushi at my house. I said it was HRC62 and the ad said 60-62. Let me ask a question. When you talk about behind the edge, are you talking about the thickness where the unground part of the blade meets where the bevel begins?