Lapping a Spyderco Ultra-Fine ceramic

theonew

theonew

Joined
May 16, 2006
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The idea of upgrading my edge sharpening performance without having to buy a new stone was too tempting to me and I finally succumbed. I have a single ultra-fine sharpmaker rod I only occasionally use in the field and a well worn DMT Fine mini-sharp I've used a lot in the field, but is beginning to slow down a bit. I did some sharpening on the UF rod until it was loaded. I then went to the sink and lapped the rod with the DMT using dishsoap and running water until all evidence of the metal particles had been removed. Then did some more sharpening and lapping the metal away, and on and on. I've done this now probably about 20 times.

The results: The stone feels noticeably smoother then my other UF ceramics. It loads more evenly and more thoroughly across its surface. Gives me a higher degree of polish and makes a palpable difference in edge sharpness. My CPM M4 is sharper than I've ever felt it. It took the tiniest micro-curls off of a hanging hair. Freaky sharp. Even though the stone is smoother it seems to almost cut faster and load slower since more of the surface is being used.

This definitely is an improvement and soon I intend to lap one side of my UF bench stone with an aging 8" X 3" DMT extra-fine hone.
 
It is truly amazing results, try it on some CPM-D2, VG-10 or BM S30V, if it was not for my obsession to strop I would just stop at the stone.
 
I have mostly tool steels but I think I'll try it on some nicely done AUS-8 next :eek:

ETA: Done, Al Mar Falcon in AUS-8 is psycho, demon laser sharp now :D

I'm also noticing much, much better feedback from the stone.
 
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theonew said:
I have mostly tool steels but I think I'll try it on some nicely done AUS-8 next :eek:

ETA: Done, Al Mar Falcon in AUS-8 is psycho, demon laser sharp now :D

I'm also noticing much, much better feedback from the stone.
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No CPM-D2, no VG-10 :eek: how does this happen :D


You reminded me, I have a lonely AUS-8 blade that has been sitting untouched for a while. I just touched it up on my UF and its a hair splitting champ without any stropping, but....I....must..........strop! :) I think I need help.
 
Could this be done in reverse, using a coarser diamond stone on the medium Sharpmaker rods? Maybe a cheap alternative to the diamond rods.
 
Brutus013 said:
Could this be done in reverse, using a coarser diamond stone on the medium Sharpmaker rods? Maybe a cheap alternative to the diamond rods.
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When I lapped my medium ceramic I used a DMT XC, it brought it back to like new but that's not very coarse to begin with. Short of milling grooves into the surface I don't think its gonna get any coarser.
 
theonew, I've noticed the difference lapping makes as well. I started using a EZE-LAP fine diamond in decent shape. Its now well worn and the stones I've used it on(Spyderco's fine ceramic) puts a real nice finer edge on the knife. I think it was Hardheart that said in another thread, by lapping you don't change the grit, you change how fine the stone cuts. Good. DM
 
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What are my options for lapping? IOW, short of a DMT Fine, can I use Silicon Carbide sandpaper on a surface plate? If so, what grit(s) should I be looking at?

Thank you.
 
Okay, I bit the bullet and began lapping my UF bench stone using my essentially new DMT Diasharp Coarse 11x2.5.

I went this route because the UF is not truly flat. Neither of my two Fines are either. So I am both bringing the stone to true flat and refining the surface.

I know this is an UF stone, but under magnification even the DMT Course is laying down a much better and finer finish than the original one on the UF. Once it is dead flat, I may go over it with my XFine DMT of the same size.

Also, re some other comments, I am still not sure why this is supposed to ruin my DMTs. If they are harder than the ceramic, what is the problem?

Thanks.
 
the ceramic is very hard and tightly bound together, the lapping could pull the diamonds out of the nickel. The diamonds would be fine, just no longer mounted in your plate.
 
Say "theonew"? What do you think is happening to the stone which gives it superior abrading/polishing properties? Is it getting impregnated with sub-micron diamond dust? Or is the small particles of diamond actually polishing the Ultra-fine Spyderco stone?

Interesting needless to say :) Spyderco's ceramic stones truly has superior properties to any other ceramic stones I've ever used. I've not yet got to try out any of Shapton's ceramic stones but I would be surprised if they were any better than Spyderco's.

I have noticed one thing on any final finishing I've done on my blades. I do get more of a polishing effect from my Arkansas "Blue-Black" stone which is as smooth as glass than I have from ceramic stones. But I'm sure that technology with newer whetstones will soon surpass any other sharpening stones.
 
knifenut1013 said:
No CPM-D2, no VG-10 :eek: how does this happen :D
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I do have one blade in VG-10 but it's currently in pieces waiting for me to figure out how to remove a stripped screw :grumpy:
I have a few examples of regular D2 that I intend to polish up soon. I've never had trouble polishing those large carbides :D

JD Spydo said:
Say "theonew"? What do you think is happening to the stone which gives it superior abrading/polishing properties? Is it getting impregnated with sub-micron diamond dust? Or is the small particles of diamond actually polishing the Ultra-fine Spyderco stone?
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I'm pretty sure it has nothing to do with diamond dust and just works better since the surface is smoother.

hardheart said:
The diamonds would be fine, just no longer mounted in your plate.
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I intend to give them to my wife as an anniversary present :thumbup:
 
Thank you for the answer.

But wouldn't dislodging the diamonds be more a matter of using too much pressure, rather than how hard the ceramic is? Also, the stones are both pretty darn flat, so it is not like scraping a sharp edge into the diamonds. I see it more as a matter of abrasion--which means the diamonds win--than a test of the bond's strength.
 
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John Frankl said:
But wouldn't dislodging the diamonds be more a matter of using too much pressure, rather than how hard the ceramic is?
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My answers are by no means definitive, just speculation. I would say that the hardness of the ceramics or other such stones would be the only way for the diamond bond to 'see' too much pressure. If you epoxy a faceted stone to a plate and plow it through a block of styrofoam, there won't be high force against the epoxy bond because the styrofoam will not resist much and just break down. But, if you go from a block of styrofoam to a block of white oak, maybe then the wood resists the stone enough to stress the epoxy bond until it fails, even though the stone is much harder than the wood.
 
hardheart said:
My answers are by no means definitive, just speculation. I would say that the hardness of the ceramics or other such stones would be the only way for the diamond bond to 'see' too much pressure. If you epoxy a faceted stone to a plate and plow it through a block of styrofoam, there won't be high force against the epoxy bond because the styrofoam will not resist much and just break down. But, if you go from a block of styrofoam to a block of white oak, maybe then the wood resists the stone enough to stress the epoxy bond until it fails, even though the stone is much harder than the wood.
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Very well put :thumbup:

The synthetic diamonds are applied in a nickle plating process IIRC and with the ceramic not being far off in hardness of the diamonds its only a matter of time before all the diamonds are ripped off.
 
Yes, the diamonds get broken away, is what I've noticed.
JD, I've noticed that as well when sharpening on my Arkansas stones. (Translucent and black hard) Yes, they sharpen nicely (even vanadium), yes, their slow and yes they polish well. On the V steels they're slower and do remove the burr but then when you take the blade to the strop, wow. A nice edge results. DM
 
I trust both of you, and thank you for your answers. And I will be careful with my DMTs.

But I still do not get the analogy. My UF ceramic is quite smoothly sliding back and forth over the entire surface of the DMT without much downward pressure by me. It it can wear down the diamonds, that is a different matter. But the hardness of ceramic should not really be putting a stress on the bond that holds the diamonds in place.

Think of it in reverse. I could take a material much softer than the diamonds, say mild steel, but hold it at a 45 degree angle to the face of the stone and apply tremendous pressure. This would put a lot of stress on the bond, though do nothing to the diamonds themselves.
 
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