Sharpening a Top Chef knife.

I was asked to sharpen a 'Top Chef Knife'. I just finished and it has been a strange experience. The steel is X30Cr13. I don't know what that means but it is 'ice tempered at -300F' to a Rockwell hardness of 53 (+\-2). So this knife could be HRC 51?

This is easily the worst knife I have ever tried to sharpen. I was able to raise a burr. I flipped it and removed it. Even off of a 500 grit stone there is no bite to the edge. I took it to 2k and and it didn't really feel any different. It slices paper ok. But the three fingers test is not scary at all.

I am guessing the owner will perceive my sharpening job as an improvement but I am at a loss for how to feel about this experience. The kitchen aid knives at Target take an edge much much better. btw this knife is used by a professional.

If this knife is Rockwell 53 how hard is the average, say, bench scraper? Cause I feel I could get a better edge on a bench scraper.

Is there a best method to use when faced with a blade like this? Would you pro sharpeners refuse to touch this one?

I could be wrong but I think that kind of steel is more responsive to norton oil stones. I recently sharpened a few crappy knives at work on some pretty fast cutting stones I have and it still took a while.

Ahhh the Ol' oil stones...

LH7 will chip in at some point and recommend silicon carbide. He's right. And 2k is too high for finishing, in my experience. I sharpen my family's knives on silicon carbide, polish on 800 and strop on newspaper. It's actually not so bad. It doesn't fix the appalling geometry of the knives, but they do at least cut.

Silicon carbide AND a lot of pressure.

As I always say, **** knives need cheap stones, not waterstones(except for finishing). Silicon stone to grind and raise burr, then finish off on your best finishing waterstone. Every single 1USD stainless knives in my house are scary on fingertip tests, they BITE after finishing on oil stone and alumina strop, pops hair and push-cut paper like butter, so I wonder how this 'top chef knife' can't get to that basic level...

Chuckles what stones were you using? I had a similar problem with wustofs I foolishly tried to sharpen them on naniwa superstones... Bad idea . Switched norton oil stones then no problems at all.

I just think Chuckles doesn't know what he's doing.
I'll bet the hunky "Chef" Curtis Stone or the "Self-Proclaimed Master of the cooking universe"-Sir Alton Brown could get that thing sharp in no time. You just need some Emeril Calphalon Kitchen-Aid Cuisinart stones, that's all!
Know when you're beat Chuckles.
Resistance is futile.

Our oyster shucker has these, the look like rebranded cutcos. The scissors are pretty nice, actually.

I used a beston 500, king 800, gesshin 2k.

I'll have another chance on these in a couple hours. I will use the king 800 as the finishing stone and start with the a 220.

Sounds like heavy pressure is the way to go. I'll google silicon carbide.

See if you can end with the 500, perhaps with a few strokes on split leather, denim, linen, cardboard or whatever you have.

Gimmicky knives are great :rofl2:

Yeah, another abrasion resistant soft steel knife.

These do not sharpen like hard carbon steels (or any of the more esoteric knife steels) because they are both soft AND very difficult to abrade. You are probably pushing a burr back and forth -- the hard chrome carbides in the knife edge will move in the soft steel and produce a rotten edge.

Oilstones are one alternative, but I've had pretty good luck with fairly normal sharpening on waterstones with the proviso that you must take a great deal of care to actually remove the burr, not just reduce it to a tiny one that flops back and forth. You don't need huge amounts of pressure, but the knife will behave much differently that harder steels do. Soft stainless is the only material that I have trouble getting rid of burrs on. I do suggest raising the absolute minimum burr you can detect on each stone, and don't bother even trying to draw one on a 2k stone, just assume you get one with four or five strokes -- at that point with that steel you are polishing. Lots of "honing" strokes seems to remove the burr better than flipping and cutting into the stone, too.

Time to get a magnifier and check the edge, this will tell you quite a bit. I would also use a knife steel (very gently, as they should always be used) and check again -- if you have a burr it will show up as a ragged edge.

Another thing -- if this knife has been "sharpened" with a pull through sharpener, you will likely have serious micro-cracking even on soft steel, plus a very wavy bevel, and you may have to grind it all out.

Avoid drawing a burr on very coarse stones with these knives, you tend to end up with a sawtooth edge which will NOT respond well to fine grit stones.

I sharpened a Wolfgang Puck knife for a friend of mine, probably a similar steel although it's not labeled, and ground a new bevel with a 300 grit stone, cleaned it up with a 700 Bester, sharpened it on the 1200 Bester, and finished on a synthetic blue aoto -- very sharp. That synthetic aoto seems to do a great job on soft stainless for some reason. I've not examined the edge closely to see what the differences are between that and my harder carbon and high carbon stainless knives are, but my friend is happy.

And try to persuade the owner to go lightly with a steel -- easy to deform the edge with one on steel that soft.

Peter

I actually think for these kinds of knifes an edge pro works better than hand sharpening. You can't do anything about the geometry anyway (the usual big weakness of an edgepro) but the edge pro basic stones are mostly silicon carbide for example but I am told a cheap silico n carvide stone like this works very well for cheap crappy steels (never tried it however)

http://www.amazon.com/gp/product/B0016J5OFU/?tag=skimlinks_replacement-20

I just think Chuckles doesn't know what he's doing.

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Well, so happy your coming to town Chris. Just in time for a backhand accross the face. :clown:

I didn't realize when you guys said silicon carbide you meant 'that stone I've moved accross the country without using that is gathering dust in the basement.' Why didn't you say so!

It is basically the same as the link in the previous thread and it worked well. It feels like a cinder lock but a little coarser. I used both sides of the stone, transitioned to edge trailing only on the 'fine' side. I finished by stropping on a stone I found under a workable at the restaurant. (Maybe the 1k side of a small king combo?)

Anywho, it turned out much better. There is an edge although I don't think I would consider these knives to be 'usable' in any serious way. They seem more like gift shop souvenirs than tools. They retail at Walmart for $39.95 for three knives, a steel and a knife roll. The roll is easily the best part of the set.

Thanks for your input guys, I wasn't expecting to learn so much from this!

Humorous and instructive journey Chuckles. Perfect story for a Friday afternoon. What does Chris know?

Lol, those look a lot like the cheap set I bought to try out -- mine were $13 for a set of three in a blister pak. They had the worst of both worlds of cooking knives -- super hard abrasion resistant steel and a joke of an edge at about 40 degrees a side and a sawtooth finish.

I have still not managed to draw an actual edge on the large one, it's so darned hard I can barely make a dent in it with my King Deluxe 300, and I put a huge gouge in a Naniwa superstone 220 trying to re-grind a decent bevel. Finally ended up out in the garage with the bench grinder and a soft pink wheel to remove enough steel to get down to about 15 degrees on a side. Amazingly hard.

Advertized as "never need to sharpen", which may indeed be true if I ever get them sharp in the first place.

Get your hands on a magnifier and see what the edge looks like after you get it to cut decently, I'm interested in what you find.

Peter

I start a lot of knives like this on 120-220 belts before finishing on 500 to 1k stones . Better than new, never gonna be great.

Advertized as "never need to sharpen", which may indeed be true if I ever get them sharp in the first place.

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You just reminded me of a 'made in China' knife I saw here, "Never needs sharpening", what kind of claim is that??:running: Maybe some kind of new technology/super steel which the knife sharpens itself when it cuts?

Get your hands on a magnifier and see what the edge looks like after you get it to cut decently, I'm interested in what you find.

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I'll take out the loupe when I get home tonight and see what I can see. The scratch pattern from the silicone carbide stone was intense.

Mrmnms said:

I start a lot of knives like this on 120-220 belts before finishing on 500 to 1k stones . Better than new, never gonna be great.

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:goodpost:
Thats the way to go with those kind of knives, they should not come near any good stone...
I just raise a burr with 120grit belt and strop on a old leatherbelt 2-3min tops!

The edge on that cheap knife set was frighteningly bad -- very coarse grind at a very shallow angle. They would indeed saw through most anything, and as hard as they are, I'm sure would never lose what edge they had in normal use, but it was a horrible edge. You could see the serrations with the naked eye. It would, I'm sure, SAW through anything, but cut? Only with help from a hammer on the back edge.

Maybe this winter when I need a project to use up a couple snowy evenings in the basement I'll actually get them sharp. Very light, crappy hollow plastic scales, I don't like the shape, but I'll see what they do sharp.

You can put a really nice edge on soft stainless if you put the time and effort into it, but it won't last long, and if the user doesn't know how to keep the edge formed properly with a steel, will become blunt fast. A very rough sawtooth edge from a coarse stone will saw better, but it's not really sharp and will still not come back with a steel very well.

This is one type of knife where pull through sharpeners are somewhat useful -- it's impossible to put a decent edge on them anyway.

Do take a look at it though -- it's always possible it's much harder than you think. Cryo treatments can do strange things to steel.

Peter

i use this
http://www.amazon.com/gp/product/B0016J5OFU/?tag=skimlinks_replacement-20
and then finish on gessh 600, but only because i already had the gessh, otherwise i would use another cheap silicone carbide 600 grit stone.

It is amazing to me that people buy these crappy knives when my local Costco is selling a 10" and 8" Tramontina Pro set with a geometry and steel similar to Victorinox Forschner for $13.79 for the 2(!) or 2 tramontina santaku's for $11.79 or even a Komachi HD set with all the basic knives for about $20 (The steel in the latter is also pretty crappy and not as good as the steel in the tramontina's I think but they are sharpenable because I think the steel is like 440a or some such.)

An example of marketing at work

My 1$ 7" made-in-Japan Gyuto beats this crap.

Be honest. Tell them to get a better knife.

I am giving this person a Wustoff 8" chef knife and a forshner parer that I have sitting around. After seeing this knife up close I can't in good conscious let someone go to work with these things. It's not even one of my employees.

But it's top chef!!