White #2 goes dull fast

Is it expected that acidic foods will dull white #2...the first three tomatoes seem easy to cut...then it just gets duller and duller. I am not rock chopping, just push cutting gently.

Oddly enough my Shun classic VG10 retains more bite on the edge than the White #2. My blue #2 gyuto keeps its edge longer than the both white knives. One white is workhorse, the other is laser. But the Shun...I hate to admit holds it's edge more predictably.

wire edge maybe? even for carbon that seems like fast deterioration.

Wire edge, almost certainly. White 2 does dull fairly quickly in an acid environment, but the only time I've had it dull that quickly is when I've had a wire edge. Stainless is going to be less susceptible to acid damage, than carbon. It's why I bought a Tanaka SG2, as my bad back (4 bulged discs, now) doesn't take well to sharpening, and I want a knife that will take minimal maintenance.

If you have a smooth steel or glass rod, try steeling it very gently a couple of times after you start having problems cutting the tomatoes. If the edge comes right back you have a wire edge. I have a couple of white 2 masakage's that hold a great edge.

+1 on smooth steel or ceramic between trips to the stones. Just a few lite measured strokes. Easy could dice a 25# case of tomato's for Lomi Salmon. Peeling pineapples not a problem with thin edged carbon gyuto's.

definitely wire edge.

Trick is using less pressure with fine stones? That's how I try to deal with my wire edges. It's a frustrating problem when you think you got it sharp and after half a salad the knife isn't cutting.

A trick I learned from Jon is to use the scrubby side of a double-sided sponge to remove the wire edge. Works great. I just swipe the edge on the sponge at a 45 degree angle.

EdipisReks said:

A trick I learned from Jon is to use the scrubby side of a double-sided sponge to remove the wire edge. Works great. I just swipe the edge on the sponge at a 45 degree angle.

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I do the same when removing the burr. wire edge in my experience comes from over doing it on the high grit stones.

I'm only using a 1k and an Aoto I bought second hand from a Sushi chef. I guess I'll have to try to get the wire off. But it seems frustrating. It's like I can get it to cut soft tomatoes but only with the 1k stone. When I move up in grits I get an edge with not enough bite to cut tomatoes.

I do believe I need to get a 500 grit stone in my progression to help set the bevels better. I was thinking about ordering one but for the price I might as well just get the three stone set offered by Dave...the 500, 1k and 5k...seems good for the price. Since I already have a 1k I could alternate the two to avoid dishing.

DaninMD said:

I do the same when removing the burr. wire edge in my experience comes from over doing it on the high grit stones.

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I don't make a particular distinction between them, myself.

^^ what he said...

A trick that I find helpful is to bang the freshly sharpened edge on a cutting board a few times, if it holds up then there is no wire. Saves taking the blade to food only to find out that you have to go back to the stones.

How about a couple of stops on your finishing stone? Or maybe run it through a bit of wood or hard felt. Also, there's the bend-the-edge-on-your-thumb test to check that you haven't gone too thin.

EdipisReks said:

A trick I learned from Jon is to use the scrubby side of a double-sided sponge to remove the wire edge. Works great. I just swipe the edge on the sponge at a 45 degree angle.

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The trick dulls my Misono Swedish a bit, but that's relatively soft. Needed after that a few strokes on a snow-white 8k. I tried with a few strokes along the edge. Not sure if that was what you meant, though.

Benuser said:

The trick dulls my Misono Swedish a bit, but that's relatively soft. Needed after that a few strokes on a snow-white 8k. I tried with a few strokes along the edge. Not sure if that was what you meant, though.

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I just kinda lightly swipe at the scrubby with a knife edge. Perpendicular to the edge, not parallel, as you aren't cutting in to the sponge.

EdipisReks said:

I just kinda lightly swipe at the scrubby with a knife edge. Perpendicular to the edge, not parallel, as you aren't cutting in to the sponge.

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Thanks! Will give it a try.

I've heard more than once that an aoto or in my case a synthetic aoto, isn't a good place to stop for hard steels. Works wonderfully with soft stainless, giving a long lived and very sharp but slightly toothy edge that cuts very nicely.

On hard steel I suspect you are sort of in no-mans-land, no longer sawtooth but not really cleanly apexed and sharp, either. Worst of both worlds, so to speak. Either stop with the 1K grit and strop on something, or get a finer grit stone to polish with.

I finish my Chicago Cutlery 440C on the "aoto" and strop with chrominum oxide on a smooth piece of wood, gives me knives sharp enough I have to watch handling them. Harder steel (Korean "cow knife" and my junk Santoku set of very hard but essentially square edged steel) get some time on 3000 and 6000 grit stones before I strop. Seems to work pretty well so far. That Korean "cow knife" is razor sharp and cuts developing pecans even after they get woody with no change in sharpness.

If you don't have access to a finer stone, strop on some writing tablet backing paper or newspaper with black print -- either will be abrasive enough to give you a little more polish than the aoto. You really need some finer grit stones for that steel, though.

All that is not to say you don't have a wire edge/burr problem, it's quite possible that the issue is a very fine and weak burr that will not come off on the aoto. Nothing more annoying that a freshy sharpened knife that feels really dull.

Peter

psfred said:

Nothing more annoying that a freshy sharpened knife that feels really dull.

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:rofl2:

That is funny.

been rocking a ginga white #2 for a over a year. In my experience it goes from really sharp to a bit dull pretty fast, maybe one short cutting session with scallions, but holds at 'usably dull' for quite some time, a few more days anyways

TheDispossessed said:

been rocking a ginga white #2 for a over a year. In my experience it goes from really sharp to a bit dull pretty fast, maybe one short cutting session with scallions, but holds at 'usably dull' for quite some time, a few more days anyways

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I have been using a Ginga in white #2 for about six months and this ^^ has also been my experience. I think it would definitely benefit from having a micro-bevel!

I have a Yusuke W#2 special thin that's use for herb mincing and it keeps its edge pretty well.

But because the steel responds so well to stropping, I find that's all it takes to make the blade sticky again.

I think generalizing that W#2 knives dull significantly faster than really harder steels might be going a little too far though. We all know the quality of the steel lies in the HT not the flavor of the steel. Having said that I don't have a lot of experience with W#2 so take my input with a dash of salt, a be it, Fleur de sel.

I defer to Jon B. and Dave M. for more insight.

Wouldn't a wire edge be more likely to happen on VG10 than white steel? If you are getting good long lasting edges on VG10 and blue 2, I am guessing that your sharpening technique is not the problem. Maybe poor heat treatment on the white?

I have a konosuke white #2, and it gets wicked sharp, and stays sharp for a long time, but not that wicked sharp, I'm going to try and run it on a smooth ceramic rod today, just sharpened it up 2days ago, and see how it responds to that

For the record...my sharpening technique is not great. The knives I have all have been oversharpened, bird beaked around the tip a bit. I'm learning to work the tips less, keep better angles etc...

I believe I need to get a coarser stone and set new bevels. The Shun VG10 knife has a totally radically different bevel than the factory, it's now highly convexed and not as thin as the factory grind...This I think really helped improve the chipping problems commonly associated with the Shun knives.

I took the knife to a cheap coarse stone, followed by a 1k treatment. I then banged it hard on the cutting board, and took it through a cork, and the dishpad...So far it cuts tomatoes nicely.

Honestly I like a good bite on my knives because I'm mainly doing mirepoix and veggies. I do believe sometimes that I am rounding my edges and I'd like to know a good way to avoid it.

The heat treat on the knife is not defective...unless Jon sold me a dud which he did not. I believe the knife needs thinning before it gets to be a real performer.

Sorry I haven't been following this thread, but if there's potentially a problem with something I sold, shoot me an email. I'm in the far north of Japan right now working from my cell phone, so it's hard to read this thread.