An Existential Hardness Question

tiguy7 said:
I agree with most everything you say except my EDC is hardened to HRC 67 and sharpens easily on Shapton Glass Stones which are Aluminum Oxide. I don’t consider Al203 stones to be special equipment. The Spyderco Sharpmaker Stones also make short work of sharpening my EDC.
Click to expand...

You are a knifemaker. I said folks like you could do it with their specialized equipment.

The average home user does not have your equipment. He has a simple stone at best. Rc67 is going to be hard to sharpen for most anyone who isn't a knifemaker.
 
My softest abrasives are Limestone and Quartz, and they would have a problem 67HRC steel. I guess the exposure of the average homemakers to Al203 would be crock sticks at the hardware store.
 
For quick touch ups I use a 600 grit diamond crusted steel. As long as one is careful with the angle it works very well on my hardest knives.
 
DeadboxHero said:
This is Spicy White Steel, 26C3.
at 66rc.

This knife has a fine array of iron carbides with very fine grain with a good HT, very high edge stability steel.

There are many benefits to higher hardness as seen in the video.
Click to expand...

That is very impressive. I saw another demonstration of yours with Spyderco Rex 45 and a brass rod, also impressive. On paper these seem like very different steels; how do they compare in use? How does the optimal geometry for each differ?
 
Stacy E. Apelt - Bladesmith said:
I buy 3/8" and/or 1/2" by 8.5" long ceramic kiln rods in bulk and turn handles for them on the lathe. The rods cost around $2 each in 5 and 10 packs (ebay and Amazon). Glue one in the hole and you have a great ceramic strop rod for less that $5. They don't sharpen a dull knife, but will restore an edge in a few passes if the edge is still servicable. They can be made even cheaper with the shorter 4.5" sticks. Make some and give them away with a high end knife.
Click to expand...

That sounds like a great idea but "ceramic kiln rod" isn't bringing up much in search. Could you help me find these?
 
Mr.Wizard said:
That sounds like a great idea but "ceramic kiln rod" isn't bringing up much in search. Could you help me find these?
Click to expand...
Also try a search on "ceramic radiant rod" (for BBQ grills). these usually come back with hollow-core rods, but the outside surface is the same, and should work just as well

Stacy's comment on these is brilliant. I have made and given away several with short (4.5" or so) rods glued into 1" dowels for handles. In my own kitchen I actually just keep a bare 8.5" rod (no handle) and use it frequently....
 
I wonder how these inexpensive rods compare to an Idahone? I am biased to expect the Idahone is better because of the price I paid, but I am pleased with it.
 
Mr.Wizard said:
I wonder how these inexpensive rods compare to an Idahone? I am biased to expect the Idahone is better because of the price I paid, but I am pleased with it.
Click to expand...
I do not know ... but my guess is that the difference (if any) is in the surface texture ... the hardness of alumina does not really (I dont think??) vary much ... and as long as it is harder than the steel - it will still cut it. It would be interesting if you bought some plain old ceramic rods and let us know how they compare to the idahone??

I would tend, though, not to pay much attention to the price of a bought product. As a manufacturer - buy a rod in bulk for say $2, buy handle material for maybe another $1, put labor and overhead into putting the thing together (including the metal loop on the end) and you will add maybe something like another $6. packaging is surprisingly expensive .... that box it comes in (along with appropriate packaging and cushioning to protect that brittle ceramic from breakage from the dock workers (if shipped by sea) and the Fedex handlers, adds maybe another $3 per sharpener. My cost is then something like $12. I want to make a good profit, so I sell it to the store for something like $24 (yes, markups really are that high - actually usually higher). The store then wants to make a profit to make up for their storage/inventory/overhead costs - so they add maybe another $10-$15 to the price ..... and you are starting to push the price you paid for that Idahone. Sorry - through history the middlemen have always made a HUGE profit and the cost of production is a small amount of the cost to the final buyer....
 
Oh, I get that. I am not intentionally biased, it's just hard not to subconsciously want/expect something you paid extra for to be worth it. I have tried several ceramic products including a couple of rods that superficially look similar to ones you linked, and they are not of the same quality as the Idahone Fine Rod or Spyderco Fine Tri-Angle. Surprisingly the Idahone Fine bench stone was also not of the same quality at least in terms of finish. I wrote a bit about that here: https://www.bladeforums.com/threads/stone-photos-chinese-ruby-and-idahone.1707538/ I did not image the other rods I have but I think I will soon since I've got the time.
 
Mr.Wizard said:
Oh, I get that. I am not intentionally biased, it's just hard not to subconsciously want/expect something you paid extra for to be worth it. I have tried several ceramic products including a couple of rods that superficially look similar to ones you linked, and they are not of the same quality as the Idahone Fine Rod or Spyderco Fine Tri-Angle. Surprisingly the Idahone Fine bench stone was also not of the same quality at least in terms of finish. I wrote a bit about that here: https://www.bladeforums.com/threads/stone-photos-chinese-ruby-and-idahone.1707538/ I did not image the other rods I have but I think I will soon since I've got the time.
Click to expand...
Interesting. Do your sharpeners have a smoother, or more, rough surface texture?
 
My favorites, the Idahone Fine Rod and recently Spyderco Fine Tri-Angle, are very smooth with no roughness and a very fine velvety matte finish. The lesser products are noticeably bumpy/grainy by comparison. I think the cheap rods are from a CRKT Slide Sharp but I'm not positive.
 
Mr.Wizard said:
My favorites, the Idahone Fine Rod and recently Spyderco Fine Tri-Angle, are very smooth with no roughness and a very fine velvety matte finish. The lesser products are noticeably bumpy/grainy by comparison. I think the cheap rods are from a CRKT Slide Sharp but I'm not positive.
Click to expand...
got it. thanks.
 
Not a necropost, but rather an update to the thread :-)

I went ahead and got some ceramic rods and have been using them on my harder blades. They do indeed work on the harder blades without damaging them, BUT they have their limits. A couple weeks ago I was slicing some nice ripe heirloom tomatoes for a tomato salad, and two of my favorite knives were really struggling - more tearing instead of effortlessly cutting(the knives are a nakiri I recently re-ground the bevels on, and an old Sabatier "Nogent" (I love the feel and balance of that knife)):
upload_2020-9-16_11-34-2.png

So .... I took the ceramic rod to the Nakiri (definitely not the first time, but the most recent of many such touch-ups). the result was a little bit of an improvement, but definitely not where I would want it to be:
upload_2020-9-16_11-35-56.png

So .... I went after the Nogent knife with a steel: it basically performed just the same as the Nakiri with the harder blade:
upload_2020-9-16_11-37-18.png

So .... both knives hit the point where in-kitchen touch-ups just would not bring them back to "effortless sharp". Both were fully sharpened on my grinder at about the same time, and they both hit this "I have got to really sharpen this knife" point at about the same time .... but up until that point I was ok with the ability of either the ceramic rod or steel to touch up each blade in the meantime... So, I am still somewhat stuck with the question of, from an in-kitchen maintainability and usability perspective ... should the statement "harder is better" really be such an absolute statement????

Now, that said, I did last night take the Nakiri to the grinder (I was cutting up a lot of vegetables to grill), and I do have to admit that right off the grinder, the harder steel with the shallower bevel and much smaller BTE thickness is an absolute pleasure to use .... but over time the two more or less converge in performance. So unless a user is truly able to immediately and consistently sharpen a blade ..... is the difference really that absolute?? (for reference, it took me almost 3 weeks between saying "I need to sharpen this" and actually doing so ......)

aside - I am in the process of replicating that Nogent profile in 0.07" thick S35VN. I'm really looking forward to seeing how that blade turns out....
 
Necropost necropost
Get him Stacy ;)
 
Cushing H. said:
Not a necropost, but rather an update to the thread :)

I went ahead and got some ceramic rods and have been using them on my harder blades. They do indeed work on the harder blades without damaging them, BUT they have their limits. A couple weeks ago I was slicing some nice ripe heirloom tomatoes for a tomato salad, and two of my favorite knives were really struggling - more tearing instead of effortlessly cutting(the knives are a nakiri I recently re-ground the bevels on, and an old Sabatier "Nogent" (I love the feel and balance of that knife)):
View attachment 1419998

So .... I took the ceramic rod to the Nakiri (definitely not the first time, but the most recent of many such touch-ups). the result was a little bit of an improvement, but definitely not where I would want it to be:
View attachment 1419999

So .... I went after the Nogent knife with a steel: it basically performed just the same as the Nakiri with the harder blade:
View attachment 1420000

So .... both knives hit the point where in-kitchen touch-ups just would not bring them back to "effortless sharp". Both were fully sharpened on my grinder at about the same time, and they both hit this "I have got to really sharpen this knife" point at about the same time .... but up until that point I was ok with the ability of either the ceramic rod or steel to touch up each blade in the meantime... So, I am still somewhat stuck with the question of, from an in-kitchen maintainability and usability perspective ... should the statement "harder is better" really be such an absolute statement????

Now, that said, I did last night take the Nakiri to the grinder (I was cutting up a lot of vegetables to grill), and I do have to admit that right off the grinder, the harder steel with the shallower bevel and much smaller BTE thickness is an absolute pleasure to use .... but over time the two more or less converge in performance. So unless a user is truly able to immediately and consistently sharpen a blade ..... is the difference really that absolute?? (for reference, it took me almost 3 weeks between saying "I need to sharpen this" and actually doing so ......)

aside - I am in the process of replicating that Nogent profile in 0.07" thick S35VN. I'm really looking forward to seeing how that blade turns out....
Click to expand...

You need to be hard enough not to roll. You get some extra wear resistance from hardness, but Larrin’s testing has shown it’s never going to get you to PM mid carbide steel wear resistance. You will have a hard time even getting to aeb-l wear resistance. You can go thinner with harder, which holds its edge longer. Maybe the harder knife can be ground thinner yet to increase edge holding?
 
You must log in or register to reply here.
Back
Top