Spyderco Ultrafine stones... disapointing?

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bubblewhip

Joined
Dec 18, 2009
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It seems my 6000 grit ultrafine stones are running into issues when I polish a blade. My steps go like this (120 grit XXC, 250 Grit whet, 1000 whet, 6000 ultrafine)

The bevel looks polished and sometimes I take a very sharp edge but for some specific knives like SAK's, S30V, or even VG-10 blades They tend to feel more dull or completely dull once I hit 1000 grit. 120 was very toothy as to be expected but sharp, 250 was toothy, 1000 was somewhat toothy and somewhat polished but 6000 was zero teeth but not very sharp. For the purer steels it seems like when you polish it that far it tends to loose all it's bite but why isnt it sharp? It can barely slice paper at times. I did a beat up (older) Old timer knife out of 440C i think it was back then and also BM 154CM's and because their not very pure I think they tend to put on a better edge in 6000. Is this normal? Am I doing something wrong? The bevel is completely mirror polished as far as I can tell that must mean the edge has been polished, but the blade just feels not very sharp.
 
my theory is that at that level of polish, there is virtually no "tooth" left in the blade. It should push cut well, but wouldn't slice or draw cut as well as when sharpened to a lower grit.
 
bigbcustom said:
my theory is that at that level of polish, there is virtually no "tooth" left in the blade. It should push cut well, but wouldn't slice or draw cut as well as when sharpened to a lower grit.
Click to expand...

I dunno feels like I can rub my thumb over the edge literally.
 
Just like stropping you can roll your edge with fine grit stones. One stroke too high of a angle on one side and it will mess up the edge you have worked to get. You basically create a microbevel to one side and because its something you really don't notice all the following strokes go back to polishing the main bevel leaving the micro untouched.

Water stone or ceramic? (when I hear UF I think ceramic)

If water stone are you using edge leading or edge trailing strokes?
 
I think the Spyderco UFs are ceramic, and if you don't keep any ceramics sparkely clean they don't perform well at all. A good way to clean ceramic is to let the acid in Bar Keeper's Friend work on the metal embedded in the stone. Make a strong concentration of powder to water (kind of like a runny paste), and let it sit on there for only about a minute. Should rinse right off. Also use very very light presure with all ceramics.
 
knifenut1013 said:
Just like stropping you can roll your edge with fine grit stones. One stroke too high of a angle on one side and it will mess up the edge you have worked to get. You basically create a microbevel to one side and because its something you really don't notice all the following strokes go back to polishing the main bevel leaving the micro untouched.

Water stone or ceramic? (when I hear UF I think ceramic)

If water stone are you using edge leading or edge trailing strokes?
Click to expand...

The UF is ceramic from Spyderco. I work all my bevels until I can clearly see the scratch marks of the next grit above it. 120 leaves a very evident scratch mark, then 250 I wait until the scratches become tighter all the way till the edge and then 1000 I wait until it becomes polished on the entire bevel and then 6000 until I see a mirror like surface all the way to the edge. I run my Ceramic stones with water laced with soap, makes a very good lubricated surface. Sometimes I occasionally mess up my reprofiling and the one side has a higher bevel than the other, but I don't believe I'm causing a micro bevel to occur since my polishes are through the entire bevel. Weird enough my family's cheap kitchen knives take a very razor edge with the UF and my high quality spyderco's do not.
 
My mistake, I should have looked at the title again :o

The 6k messed me up, the UF can't really be graded as a grit but if you wanted to it would be closer to a 8-10k water stone. 3 micron is its more accurate grading.

Water or soapy water does noting for a ceramic and may even hurt your efforts. use them dry and clean with bar keepers friend when needed.

Skipping from 1k to a UF ceramic is one of the issues, until you get a middle stone try just using the UF for microbevels. A well formed 1k edge microed with the UF will give utility razor like sharpness.

What are your 250 and 1k stones?

Stainless steels will yield best results from the UF and especially SAK's and VG-10, do you have any close up pictures of the edge?
 
Never mind. I think I did something wrong. I was redoing my Leatherman TTI in S30V to show you a picture since after 6000 I brought it back down to my sharpmaker fine stones since they would actually make them sharp. Now on 6000 it's taking a razor edge!
 
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