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Best way to sharpen my knives - Page 2

post #31 of 49

don't know if Galley Swiller is an engineer or other - but his facts are straight.

 

metals do certain things at certain temperatures.  boiling water (aka 212'F / 100'C) is not one of those temperatures.

 

"heat treating" a metal involves bringing it to a high temperature and then cooling the metal at a controlled rate.  depending on the metal/alloy/inclusions/pure state/etc/etc/and things way over most peoples' head.... the cooling phases affects how the metal "crystallizes" and how various atoms within the "metal" react.  there is zilch comma zero question that "heat treatment" drastically how a metal will perform, and in this case, "as a knife"

 

should you encounter some company espousing the superior degrees of metallic "....ites" (various apply) - RUN - they're so full of BS you'll never get to anything of "truth"

 

"tempering" a metal involves bringing the metal to a high enough heat that it "relaxes" and allows any internal built up "stresses" to dissipate.   there are a lot of "words" that get associated with "tempering" - annealing / lehring / etc.  "engineers" recognize that these are all pseudo-terms for the same physical process / thing.

 

marketeers otoh depend on the general public being w-o-w-e-d by big words / terminology - basically "if I can't baffle you with brilliance, let me at least befuddle you with bullsh*t."

 

a "knife" has to be hard enough to take and keep a good edge, and "soft" / "flexible" enough to not snap in half when you use it.

 

discounting the "BUT WAIT!  THERE'S MORE!" 2-3 AM tv hucksters, all those pesky "top name" companies have figured this stuff out.

post #32 of 49

We're running far afield of the OP but just for the sake of accuracy I'll correct myself.  I thought I had heard that boiling temperatures could ruin the benefit of crygenic heat treatment but this is not true.  CT is used to break down any austenite formations left after quenching, it breaks the austenites down to the desired martensite structures.  Once done it would take high heat to change things.

 

Rick

post #33 of 49

Daniel - sorry to disappoint you - but I can't claim to be an engineer - I'm just a (retired) former title examiner.  My former job did require me to look up esoteric information, and required me to be able to write up a summary which could be followed by others.  It also required a significant level of accuracy, with dire consequences if I failed at it.  I did work with civil engineers on an extremely frequent basis - so mebbe that's how things rubbed off onto me.  And that's all I will want to claim.

 

Dillbert, I share your skepticism about marketeering - but I think it's more important to be able to recognize and point out the BS and move around it, rather than run screaming from it.  Clarifications, corrections and mutually educating each other is what these forums should be about.  If we do it right, we can at least counter some of the BS.

 

As for heat treatment, that is a critical point of difference between the various manufacturers and bladesmiths.  But it shouldn't be much of a mystery as to the general process, either.  It's just 3 parts: annealing, quenching and tempering.  And since each manufacturer/bladesmith does it differently ("trade secrets"), that's one of the comparative points which keeps forums like this alive with people like us constantly comparing and criticizing the end products.

 

...nuff said

 

 

Galley Swiller

post #34 of 49

I am an engineer.  in fact, a civil engineer - but spent the majority of my career in "process control"

secondary metal processing.  cutting/turning tube / forged blanks to shape; heat treating, annealing, grind, polish and finish.

 

I'd wager there's not more than 2 members on this board, if that, who can define the difference between austinite, martensite, and googlesite.

 

that's why when one encounters the huckster vendor telling the crowd that: ". . . and everyone knows higher martensite makes a better knife" it's time to run - liar liar tent on fire.  nothing but a high-commission parrot on display.....no idea/clue what he's talking about, just gets the crowd nodding "yes, yes" and an able assistant to collect credit card info.

 

fwiw, the various steels used in knife making require different approaches to heat treat...and following process.  and even if using the identical steel - rare in the knife business - can be "treated" with more than one single set of "time&temperature" parameters and achieve, in the end, an "equal" result - even if a scanning electron microscope (required) finds steel X with more dddd...ite than steel Y.  and, making life even more interesting, I have never ever seen any published engineering standard that establishes X-ite this or Y-ite that or X% vs Y% is needed for "the best (which is undefinable, anyway) knife"

 

life does not fit into a 140 character Tweet.  bit more to it than that.

 

bottom line:  99.999% of the huckster's techie stuff your never heard of are absolute BS - knives and "waterless cookware" being the most popular topics.

 

 

post #35 of 49
All that being said, it doesn't need a high level of knowledge to state boiling water won't modify steel properties.
post #36 of 49
Quote:
Originally Posted by Dillbert View Post
 

 

fwiw, the various steels used in knife making require different approaches to heat treat...and following process.  and even if using the identical steel - rare in the knife business - can be "treated" with more than one single set of "time&temperature" parameters and achieve, in the end, an "equal" result - even if a scanning electron microscope (required) finds steel X with more dddd...ite than steel Y.  and, making life even more interesting, I have never ever seen any published engineering standard that establishes X-ite this or Y-ite that or X% vs Y% is needed for "the best (which is undefinable, anyway) knife"

 

life does not fit into a 140 character Tweet.  bit more to it than that.

 

bottom line:  99.999% of the huckster's techie stuff your never heard of are absolute BS - knives and "waterless cookware" being the most popular topics.

 

 

 

 

Ahaha, you must have heard some of Bob Cramer's hype in particular.  My field is engineering machine design, obviously not that familiar with heat treatment though.  Not meaning to go OT again, but there are areas where specific heat treatment is critical, it took decades for other companies to duplicate Johannson's stress releiving procedure in the making of precision gauge blocks.

 

 

As a creative designer I have learned not to discount any possibilities untill having done adequate research, even purely faith-based beliefs can have validity.

Rick


Edited by Rick Alan - 10/10/13 at 6:16am
post #37 of 49

>>Bob Cramer . . .

 

not really - I'm not "into" knives except to keep mine sharp.  my own experience with heat treat was on an industrial scale - thousands of pcs at a clip - much thicker section than a knife.  furnaces the size of small houses.....annealing ovens 300 ft long.... the assignment was to develop and document - then 'control' all the 'details' of how that equipment was operated so every piece from first to last had "identical" structure - a slightly different world than custom knife making.

 

I recall a TV (PBS?) show about "master craftsmen" - and if I remember right it was Bob Cramer.  I rather suspect every custom knife maker has their own preferences -

making knives one at a time like that certainly involves a lot of experience to avoid producing a boo-boo. 

 

my job was to get the process so well under control that producing a 'perfect' batch every time was merely ". . . and then push the green button."

post #38 of 49

I've found that a lot of these knife discussions especially concerning the asian stuff are totally overwhelming and choose not to read them much.  They come across like an infomercial.  Hmmmm.   And I'll go elsewhere to split hairs.  Still, though, I love my Sabatiers!   :smoking: 


Edited by kokopuffs - 10/12/13 at 6:17am

Best and I'm a foodie.   I know very little but the little that I know I want to know very well.

 

-T

Brot und Wein
(1 photos)
 
Reply

Best and I'm a foodie.   I know very little but the little that I know I want to know very well.

 

-T

Brot und Wein
(1 photos)
 
Reply
post #39 of 49
idaho kosher,
here is a quick and easy way to keep your knives sharp. the investment is low. you use silicon carbide sandpaper and a mouse pad or piece of sorta soft foam rubber. here is a better explanation of how to do it: http://zknives.com/knives/articles/sandpapermousepad.shtml
the ideal here is what touches your knife blade is thrown away when you are done, so you should not have any issues with Kosher Law. you should be able to get a basic kit together for $25 or so.
the sandpaper is available in grits to 2000, more than fine enough for any knife. you can find it on ebay or any industrial or auto body supply site.(the finer grits are used between coats of paint or varnish).
hope this is helpful,
the old sailor
Scott just a tired old sailor glad to be home from the sea
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Scott just a tired old sailor glad to be home from the sea
Reply
post #40 of 49
Quote:
Originally Posted by Scott Livesey View Post

idaho kosher,
here is a quick and easy way to keep your knives sharp. the investment is low. you use silicon carbide sandpaper and a mouse pad or piece of sorta soft foam rubber. here is a better explanation of how to do it: http://zknives.com/knives/articles/sandpapermousepad.shtml
the ideal here is what touches your knife blade is thrown away when you are done, so you should not have any issues with Kosher Law. you should be able to get a basic kit together for $25 or so.
the sandpaper is available in grits to 2000, more than fine enough for any knife. you can find it on ebay or any industrial or auto body supply site.(the finer grits are used between coats of paint or varnish).
hope this is helpful,
the old sailor

 

Once finished using my oilstones, I followed the procedure listed above using wet-or-dry (aka carbide) sandpaper and achieved about the best edge I ever got.  And it was thanks to the local automobile body shop that provided me with  a variety of wet-or-dry papers.

Best and I'm a foodie.   I know very little but the little that I know I want to know very well.

 

-T

Brot und Wein
(1 photos)
 
Reply

Best and I'm a foodie.   I know very little but the little that I know I want to know very well.

 

-T

Brot und Wein
(1 photos)
 
Reply
post #41 of 49
In my experience sharpening with sandpaper is great as long as you're dealing with basic carbon steel. Expect serious burr / wire edge issues when you do this with stainless.
With basic carbon the burr will fall off when you go to a higher grit and reduce pressure. With stainless, whenever it falls off, it leaves a damaged edge. With a lot of stainless, it will never fall off, and has to get abraded away. That requires a much more precise movement than I can perform on sandpaper, and I do need the response of the stone in feeling and noise to know how far I am.
post #42 of 49
Quote:
Originally Posted by Benuser View Post

In my experience sharpening with sandpaper is great as long as you're dealing with basic carbon steel. Expect serious burr / wire edge issues when you do this with stainless.
With basic carbon the burr will fall off when you go to a higher grit and reduce pressure. With stainless, whenever it falls off, it leaves a damaged edge. With a lot of stainless, it will never fall off, and has to get abraded away. That requires a much more precise movement than I can perform on sandpaper, and I do need the response of the stone in feeling and noise to know how far I am.

Well that's helpful to know, which gives some justification to keeping this thread going, but as to the OP:

The need for separate sharpeners is not even a moot point, the article cited early on is very clear that separate sharpeners are not needed if they are drenched in water during use:

"Is there a kashrus issue in taking knives to be sharpened to a sharpener, knowing that the sharpener also sharpens non kosher knives? In our experience, the knife sharpeners are constantly bathed in water so they do not get hot. Therefore, as long as the sharpener is clean, it is permitted to sharpen on a sharpener that is also used for non-kosher knives. (Butchers sometimes subscribe to a knife-sharpening service. The butcher must ensure he is getting back his own knives after sharpening.)
Can one use the same knife sharpener for meat and dairy knives? If the sharpener gets hot (more than 120F) during sharpening, one should use separate sharpeners. If the sharpener does not get hot, then one can use the same one for meat and dairy. The knife should be washed in cool water before and after sharpening and the sharpener should be rinsed in cool water after use.
Copyright © 2009 Star-K Kosher Certification."

I pointed this out way back and gave further evidence of why it is sound according to the certifications guidelines. Interesting we haven't heard from the OP in a while, but in all fairness it took me 2 months to follow up on my "Why isn't it Mayo" post. ;-)~

And actually to regular water stones already mentioned we can add much more expensive powered wet-grinders, and also the $70 takes-no-skill MinoSharp, which even Boar d Laze found adequate enough to buy for a not-into-hand-sharpening family member:
http://www.amazon.com/Global-Stage-Sharpener-Minosharp-Plus/dp/B000WZFBOS/ref=sr_1_2?ie=UTF8&qid=1381891318&sr=8-2&keywords=minosharp+plus

Rick
post #43 of 49

Sandpaper works great on carbon steel.  When it comes to stainless, jettison that stuff.

Best and I'm a foodie.   I know very little but the little that I know I want to know very well.

 

-T

Brot und Wein
(1 photos)
 
Reply

Best and I'm a foodie.   I know very little but the little that I know I want to know very well.

 

-T

Brot und Wein
(1 photos)
 
Reply
post #44 of 49

actually on the vein of using sand paper, there is an addition to using sandpaper that works really well and involves nothing more than stropping motion.  Its a 3M product call Trizact, and it comes in 3x9 sheets.  I have used A5 and A3 after 2500 grit sand paper good success before heading to a balsa strop with CrO.

post #45 of 49
And how do you deal with burrs? That's my problem with sandpaper, when dealing with other than very basic carbon stuff.
post #46 of 49
Quote:
Originally Posted by Benuser View Post

And how do you deal with burrs? That's my problem with sandpaper, when dealing with other than very basic carbon stuff.

 

Actually I don't see why sandpaper should pose trouble in burr removal, unless its made of a relatively soft abrasive or perhaps the way it is glued down.  Trizact is silicon carbide held in film of resin and should cut fairly aggressively.  3M also makes an aluminum oxide impregnated mylar in something like 12x12" sheets that when stuck to a hard backing, like a granite surface plate, and used wet, it can be used much like any sharpening stone, though it does wear very quickly and likely requires a little extra care to avoid cutting into it.  Because of the nature of the matrix the 3K grit produces a mirror finish.  Apparently much the same for the Trizact A5.  Neat thing about the Trizact is that they have it in sanding belt form also. You might try sticking Trizact to a hard surface and see what it's like.  Now if they would just start offering more in cubic boron nitride...

 

Rick

post #47 of 49

If you are comfortable with the stropping motion, on high grit sand paper I have taken off the burr using that technique.  On Trizact I have used the same stropping motion on the foam backed A3 and A5 pads and had some amazing results.  For a lot of my knives stropping to 3 micron Trizact is good enough to have a working edge and isn't time consuming and touch-ups are easy.  But it does come down to learning curve, it will take some time to learn to sharpen on SiC wet/dry paper and Trizact.  Again this is the budget minded option, all it really costs you is a granite base to use the pads on.

 

Simar

post #48 of 49
I had to deal with the more basic w/d high grit sandpaper, and couldn't perform the motions along the edge I prefer for deburring with difficult steels. For edge trailing sandpaper is great, but it isn't the way to get rid of burrs, it's rather the way to raise them. But, again, I'm sure with better technique one may obtain much better results.
post #49 of 49

I'm a professional sharpener.  I use Japanese waterstones exclusively.  I threw away everything else.

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