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Ultrasonic Chef's Knife

seattleultrasonics.com

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Re: Ultrasonic Chef's Knife

#681

Post by tedk-42 »

mapt wrote: post #665
Zigurd wrote: post #590

Earlier quoted context omitted.

How much mineral and metal grit does one consume on a regular basis? The ceramic material from a ceramic knife blade is, obviously from just looking at it, very small. I bet the amount of grit I've eaten from having a taste for raw oysters vastly outweighs what I'd get from a lifetime of using ceramic knives.

"grit" is usually spherical or close to it, because it has seen chemical and mechanical weathering. It is often calcium crystals of some type. This is neither. These are long dagger shapes, significantly larger than a diatom, very hard, sharpened to a fine edge.

They aren't giving you 'microcuts' in your gut, any more than anything else.

Why? The force applied isn't in a uniform downward direction like you would with a knife.

Re: Ultrasonic Chef's Knife

#682

Post by dyauspitr »

Zigurd wrote: post #590
mapt wrote: post #555

Earlier quoted context omitted.

They do not stay sharp. On hard material and when overloaded, they will chip in large, unfixable chunks. On softer material, they continuously sharpen their edges at a microscopic scale, fracturing away tiny chips as they're worn, to new glassy ceramic molecular edges. A well used ceramic blade becomes micro-serrated. This sounds fantastic until you think about what is happening to the shards of hard glassy ceramic w…

How much mineral and metal grit does one consume on a regular basis? The ceramic material from a ceramic knife blade is, obviously from just looking at it, very small. I bet the amount of grit I've eaten from having a taste for raw oysters vastly outweighs what I'd get from a lifetime of using ceramic knives.

Grit is shaped differently than ultra sharp shards.

Re: Ultrasonic Chef's Knife

#683

Post by bigiain »

citizenpaul wrote: post #678
bigiain wrote: post #415

Earlier quoted context omitted.

I have one of those "roller" sharpeners, in theory a "good" one, it's from Global (the Japanese knife brand) not just an AliExpress knockoff. It works reasonably well and is definitely quick. But its not even close to "95% as sharp) as when I spend 10 mins with my Lansky sharpening kit (which is really just a small set of graduated whetstones with a jig to keep the angle right while using it). Would I recommend every…

>But its not even close to "95% as sharp Admittedly I have not made a comparison but I've seem some youtube vids where they compete various sharpening gadgets vs the pro way. They all seem to do very well even at bottom barrel prices. I'm sure defects are higher though. That lansky looks awesome I think I'll pick it up. I think the crowd on here will see this basic life skill as too much "work".... so thats why I rec…

The roller/drag-through thing is worthwhile owning, I use mine a lot more often than I get out the Lansky kit. It's probably a couple of times a month I'll find my usual knife is smooshing ripe strawberries or tomatos a bit instead of effortlessly slicing them, and a few swipes through the fine wheel on mine will make that knife slice nicely again. Mostly I get out the Lansky tools when I've damaged a knife, then I'll sit at my workbench will all my knives and spend an hour or two in a Zen knife edge grinding trance making everything stupidly/dangerously sharp. The ultra-fine ceramic hone in my kit does an amazing job, but you need to work up to it through the coarser grade hones - especially if you've been using the roller sharpener on that knife for a bit - I'm pretty sure they don't get the edge angles right in a way the the ultras fine hone can take advantage of.

I really like my Lansky kit. In retrospect I might have shelled out the extra for the set with the diamond sharpening stones - but I doubt I'll ever come close to wearing down the regular stones with my use patterns.

Re: Ultrasonic Chef's Knife

#684

Post by xxs »

giardini wrote: post #605
dlcarrier wrote: post #352

Earlier quoted context omitted.

>People spend hundreds of dollars and many hours sharpening kitchen knives... What amazes me is how many people spend absolutely zero time sharpening knives, using decades-old knives that have never been sharpened and can't even cut through cucumbers.

Amy's Trick: ============ You can sharpen (really, burnish) steel knives on a stainless steel sink edge! Stainless steel kitchen sinks are very common in USA. Gently press the knife blade almost flat against the sink edge and pull the knife handle toward you while moving it to the right (or to the left if you're left-handed). Hold the knife at the angle desired for the blade edge (endless discussions of angle are pos…

Even better trick - you can sharpen knives on the bottom of a tea cup/mug (as long as it is ceramic)... or a piece of brick.

Re: Ultrasonic Chef's Knife

#686

Post by floppiplopp »

So, some tech business took something that is practical, robust, and low maintenance, and then added a deteriorating battery, delicate electronics, and the need to constantly charge a f-ing kitchen knife. Bullshit innovation is reinventing things, but worse. I wouldn't be surprised if they at some point added AI powered cutting modes and a subscription service, because the target audience clearly is gullible morons that are easily fooled by fancy ideas of vaguely sci-fi concepts.

Re: Ultrasonic Chef's Knife

#687

Post by Jataman606 »

omnicognate wrote: post #586
aenis wrote: post #435

Earlier quoted context omitted.

I spend hours every 6 months or so sharpening knifes on whetstones. I like the excuse to have some me time, listen to an audiobook or just do some thinking. Akin to meditation. I also dont like the blades ruined through automatic sharpeners - the knifes are made of good quality steel, were made to order in Jp, and have sentimental value. I also sharpen the cheap knifes this way, tho - I like manual work.

Do you not sharpen them in between? I've had to spend hours sorting out knives that have been left far too long without sharpening, but my routine is to spend about 15 minutes sharpening them every weekend. Then they're always sharp and never get into a terrible state and need remedial work. My knives get noticeably suboptimal in a couple of weeks without sharpening, so if I left it 6 months they'd be blunt pretty mu…

Usual advice is that you need to straighten your blade every week or two and then you can sharpen it every 6 months or even a year (depends on usage of course). To straighten the blade you use honing rod which many people mistake for sharpener.

Re: Ultrasonic Chef's Knife

#688

Post by omnicognate »

Jataman606 wrote: post #687
omnicognate wrote: post #586

Earlier quoted context omitted.

Do you not sharpen them in between? I've had to spend hours sorting out knives that have been left far too long without sharpening, but my routine is to spend about 15 minutes sharpening them every weekend. Then they're always sharp and never get into a terrible state and need remedial work. My knives get noticeably suboptimal in a couple of weeks without sharpening, so if I left it 6 months they'd be blunt pretty mu…

Usual advice is that you need to straighten your blade every week or two and then you can sharpen it every 6 months or even a year (depends on usage of course). To straighten the blade you use honing rod which many people mistake for sharpener.

I have a steel honing rod but it's never seemed to have much effect. Perhaps my technique isn't right.

I also have a ceramic sharpening rod, which I use to sharpen my breadknife. That's very effective, but different as it actually removes steel. I give my straight-edged knives a few strokes on each side on a 3000 grit whetstone every weekend, which seems to keep them nicely sharp. That will slowly wear them down but it hasn't done so noticeably yet so I expect the knives to last many years.

Re: Ultrasonic Chef's Knife

#689

Post by lightedman »

thebenedict wrote: post #673
lightedman wrote: post #550

Earlier quoted context omitted.

"The innovation here is making ultrasonic hardware compact enough to fit in the knife handle." I was using ultrasonic scalpels back in 2002. They were smaller than this knife.

Were they standalone devices, or was the ultrasonic hardware in a separate enclosure connected by a cord?

Standalone but bulky, about as thick as a dry erase marker.

Re: Ultrasonic Chef's Knife

#690

Post by UltraSane »

Kirby64 wrote: post #680
UltraSane wrote: post #679

Earlier quoted context omitted.

AUS-10 is basically 440C, and is an excellent steel for cutlery (and was once considered at the very high end of stainless steels). Very stainless, reasonably tough, and honorable slicing edge retention if heat treated to a relatively high hardness (60-61HRC would be on the mark). It will sharpen OK, but may have a bit of a gummy feel on the stones and not be as easy as carbon/low alloy steels.

Again, it’s not that it’s bad per-se, it’s that it is easily outclassed by numerous other more modern steels. It’s cheap compared to more exotic stuff, and feels almost insulting at the price you’re paying for the knife. If the knife we’re discussing was sub $100 I’d have no issue with AUS-10/440C, but we’re talking about a $400 knife.

So what steel do you feel is appropriate for a $400 knife?

Some steels might work better with ultrasonics than others.

I would like to see a ceramic version.

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