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obtuse
09-26-2011, 04:19 PM
Have you ever sharpened a knife that would not get sharp? I just spent 15 minutes on my girlfriend's cheap-ass, chinese-made chef's knife. I went through a full stone progression etc. I noticed while deburing that it would make one slice into the cork and quit--dull as a butter knife. I added a 45 degree micro-bevel to the already obtuse edge and noticed the same behavior. I guess the bur was the only thing doing the cutting :tooth:. The blade is rather thick, but still bends easily. It makes me wonder if the steel is even hardened. A few minutes wasted on a knife that won't cut paper. I wouldn't even use it as a cheese knife. I guess I have justification to buy her a new knife :D. "A knife like that is dangerous", that's what I'll tell her when she finds out I've spent more money.

tk59
09-26-2011, 04:27 PM
I have a knife like that. Got it at the supermarket to use as a sacrificial knife to mess around with. I couldn't believe how hard it was to get a clean edge although the last time I saw it, I wasn't nearly as experience as I am now. Lesson learned. At least it only cost me like $5. I think it was a Hampton Forge knife, but don't quote me on it.

EdipisReks
09-26-2011, 04:31 PM
i have farberware knives that i can wear down to nothing, but cannot get sharp. they are great if you need some iron filings, though.

Amon-Rukh
09-26-2011, 04:37 PM
I've got a trio of paring knives from an unknown maker that fall into this category. I inherited them from my grandma after she passed away; I don't think they were ever sharpened or even steeled in their lifetimes. I had some spare time and tried to sharpen them 2 weeks ago, but only managed to get a *barely* passable edge out of one (which is luckily the one I like the best for sentimental reasons). I couldn't tell if my efforts did anything to the other two at all though.

Lefty
09-26-2011, 04:48 PM
Maybe the wire edge is hanging around and getting doubled over on the edge....

geezr
09-26-2011, 05:05 PM
I have a 4.5" Kyocera ceramic knife received as "payment" for sharpening a relatives knives - because I was not able to get a sharp edge on this knife :rasberry: - still trying, occasionally :bashhead:
How to sharpen this kind of knife? :tongue:

obtuse
09-26-2011, 05:08 PM
I chassed it on the stones, micro beveled it, stroped it on felt and leather, cut cork after each stone... if the bur is still hanging on there, it certainly isn't worth any more effort to remove it. If I ever decided to "sharpen" This knife again, I'll finish it on a beston 500 and leave a giant wire edge hanging there. Then I might be able to slice paper. It truly makes you a appreciate the nice steels most our knives are made of.

EdipisReks
09-26-2011, 05:11 PM
I have a 4.5" Kyocera ceramic knife received as "payment" for sharpening a relatives knives - because I was not able to get a sharp edge on this knife :rasberry: - still trying, occasionally :bashhead:
How to sharpen this kind of knife? :tongue:

diamond stones are the way to do it. you can get them reasonably sharp with a coarse and a fine DMT, stropping on diamond paste.

geezr
09-26-2011, 05:26 PM
diamond stones are the way to do it. you can get them reasonably sharp with a coarse and a fine DMT, stropping on diamond paste.

:thankyou: will try the diamonds, then maybe return to previous owner :viking:

Benuser
09-26-2011, 05:52 PM
A lot of us are used to follow the same proceedings with every knife that comes into their hands. High grits are useless with soft steels. In fact you can't get them sharp, so let's make microsaws. Thin a much as you can, build a 12 degree bevel with a J400, and get your 800-1000 for very light stropping and deburring at 17 degree. The result will be what most people call 'sharp'.

Dave Martell
09-26-2011, 06:14 PM
Hampton Forge & Farberware type knives are awful junkers, maybe even worse than Chinese bombshell steel, probably recycled Indian coke cans. The best thing I can do with these knives is grind the tip off and flatten the edge and toss them in the bin. The world is a better place without these things in it. :)

Eamon Burke
09-26-2011, 06:14 PM
Ah this is a fun thing to show a knife nut.

Those knives can be sharpened, they'll cut like crazy. But you can OVER sharpen them, and it sounds like that's what happened.

Take the chinese chef's knife you babied and put it on a 1k, build up a huge burr, flip it, deburr it. Then put it back on the 1k a little more gently and raise a small burr and deburr again. It'll cut just fine. If you've got a belt sander, put it on a fairly fine belt(doesn't really matter what grit), raise a burr, flip it once, hone it on a ceramic rod. It'll shave, it'll breeze tomato skins. Not for long mind you, but you can only ask so much.

Crap steel = Crap edge. It's how they like it.

The best thing about this is that you get to see how much the DESIGN of the knife is holding it back. The edge can cut, but the knife itself sucks. Worst I've ever seen was a Farberware Chef's...Worst. Cutter. Ever.

EdipisReks
09-26-2011, 06:29 PM
maybe even worse than Chinese bombshell steel

is this different from the Taiwanese bombshell steel? i've wanted to try a Maestro Wu knife...


The best thing I can do with these knives is grind the tip off and flatten the edge and toss them in the bin. The world is a better place without these things in it. :)

:)

Dave Martell
09-26-2011, 06:51 PM
is this different from the Taiwanese bombshell steel? i've wanted to try a Maestro Wu knife...



:)


LOL, that's actually what I meant. I have a saying about those knives...."they don't touch my stones". :D

EdipisReks
09-26-2011, 06:56 PM
LOL, that's actually what I meant. I have a saying about those knives...."they don't touch my stones". :D

well, there you go!

Dave Martell
09-26-2011, 07:05 PM
I haven't sharpened one of these (Maestro Wu) knives in years but the two that I did do back when they were first discovered were less than impressive. I was using Shapton Pros at the time and can distinctly recall the crunching noise all the way to 8k! I'd belt grind them now but I'm not bothering to hand sharpen something like that ever again.

EdipisReks
09-26-2011, 07:06 PM
well, you've saved me the trouble, Dave. :)

olpappy
09-26-2011, 07:35 PM
The best thing about this is that you get to see how much the DESIGN of the knife is holding it back. The edge can cut, but the knife itself sucks. Worst I've ever seen was a Farberware Chef's...Worst. Cutter. Ever.

this leaves me a little confused, if you have crappy design + crappy steel, I would think you'd have a hard time attributing how much of the poor performance is because of the design, vs. the bad steel.

stevenStefano
09-26-2011, 07:50 PM
I'm gonna try and get some sort of sharpness out of the crappy Victorinox house knives in work and my plan is to thin them like crazy then use a 220 and 800 stone to get some sort of bevel on them. It should be interesting, none of them have ever ever been sharpened, just steeled to death

99Limited
09-26-2011, 08:19 PM
My neighbor has a 6" Chicago Cutlery chef that I've never been able to put a very good edge on it. The last time he gave it to me to sharpen, I tried thinning it and it seemed to help but I still wasn't very happy with the results. I ended up buying Vertigo's Carter SFZG Funayuki and gave that to him so I'll never have to see that CC knife again.

Eamon Burke
09-26-2011, 09:17 PM
this leaves me a little confused, if you have crappy design + crappy steel, I would think you'd have a hard time attributing how much of the poor performance is because of the design, vs. the bad steel.

Well, the trick lies in understanding how cheap steel is intended to be sharpened. I'm getting a good loupe in the mail, and I do plan on investigating the cause of this, but cheapo knives are easily over-sharpened. You give them love, they die on you. They are like a cactus--you water it, fertilize it, keep it cool, and it dies. The steel is designed by engineers to provide results for minimal effort. A great case in point is Dave's earlier statement that Shun's SG-2 takes a screaming edge off a belt sander--they are made to be sharpened that way at the factory, and Shun has the money to find and develop the steel to do it right.

You can get a $6 knife to knock any cutting test out of the park...but cutting food shows you why it was $6. I carry a $6 knife around to show to potential customers, like "Don't believe me? Try this versus anything you are using right now.", because it is sharp as heck, for a little while. Cheap steel can be easily sharpened, but bad design is not worth fixing.

Opposing case in point: the CCK 1303. Cheapo carbon steel on a good design. Cuts like crazy for about a day, and needs to be touched up, but you can use it pretty dull because the design is good. The steel just won't stay sharp for long.



The reason why cheap steel responds so poorly to over-buffing, I have yet to deduce. But I've gotten a knife to shave arm hair and wouldn't get through a carrot.

Seb
09-26-2011, 11:50 PM
Make a bevel/make the planes meet (more or less) using a coarse or medium-coarse stone, and then use an Idahone to swipe off the stubborn burr and make a micro-bevel. I do this with all my cheap-ass beaters (of which I have quite a few, especially Kiwis which make handy steak knives among other things).

stevenStefano
09-29-2011, 08:41 AM
Just to add to this post, I tried sharpening a couple of the crappy Victorinox knives in work yesterday. There is basically no bevel on them, just a vague wavy line. Tried grinding one on a Naniwa 220 stone for about an hour and the bevel pretty much looked the same. Tried thinning it as well but it made little difference. I just gave up, guess I need something coarser or a belt sander. Not worth the hassle basically

NO ChoP!
09-29-2011, 10:40 AM
I have this little Mexican lady who works my garde manger station; she brought this fake Shun looking, single bevel chefs knife in, and tried using a Wusthof pull through sharpener on it... needless to say, the damn thing was ruined. I put it on a 220grit to return it to single bevel for her, but it didn't fix the fact it's still a POS!