About ready to spring for the Spyderco ceramic stones...

[arnman]

I just typed up a long post and hit Post, and it disappeared!  I will try to follow up soon.

Here is the abbreviated version of my post that went Poof!

I received the stones back from Spyderco, and decided to try using them as-is without flattening.  If I decide to flatten later, I have two options available: Coarse EZE-lap diamond stone or silicon carbide grit on a thick piece of glass.

I first tried free-handing a plane iron that was already ground on the Tormek.  Results were okay, but at least as good as my previous methods with sandpaper.

Second attempt was done using an Eclipse jig.  Results were much better.  I may not have spent enough time on the UF stone.

I thought that the stones cut quickly.  It was very nice not having to worry about worn sandpaper, and not having to perform stone maintenance (for now).  I expect these two stones to be my primary users, and these two grits should be exactly what I need 95% of the time. 

Other than that, I don't have much to report.  I have been immersed in some other projects.

I want to set up a method to establish a consistent blade / iron extension, to achieve repeatable bevel angles, using the Eclipse jig.  This should also help speed things up.

I would also like to combine this with repeatable primary grinding on the Tormek, so I can switch from grinding (when needed) and quickly mount the iron in the Eclipse jig at the correct angle.

Also, I want to try using these stones to prep card scrapers.  I have never really had consistent results previously.  I will probably need a new burnisher - I am looking at the Hock burnisher.  My Lee Valley elliptical burnisher seemed to get scratched very easily when trying to turn down drawn-out burrs.

[Mike Brady]

Thanks for that feedback.  I have one of the Spydercos, but do not know which grit it is .  If color makes a difference, its white.  Its wa-a-ay out of flat.  What I also have is some Sc grit and a cast iron lapping plate.  I find the Spyderco stone to not polish particularly well.  Perhaps that is why they  are sold by a knife maker,  as cutlery sharpening often calls for some "tooth" to the final edge.  I have found waterstones, though a hassle, to be the only way to get a mirror polish on A2.

[arnman]

I believe that the Fine and Ultrafine are both white.  Have you tried flattening it using the silicon carbide grit?  I have heard that the Medium stone is easier to flatten than the Fine or Ultrafine.

I did not really compare the finish left by the Ultrafine vs the 2000 grit sandpaper I used to use, but they seemed to be similar.  Maybe I should do a comparison when I get the chance.  I don't know if I have any 2000 grit left.

[arnman]

I decided to try flattening the Spyderco stones.  Previously, I only measured flatness along the stone.  I did not check transverse.  In hindsight, I wish that I had done so.  I think the Medium may have been crowned very slightly transverse, because I don't think the middle of my plane irons were being polished by the middle section of the Ultrafine.

For flattening, I used 80 grit silicon carbide on a piece of 3/8" thick glass.  I used about a half teaspoon of grit, sprayed some soapy water on it, and moved the stone in a figure 8 pattern.  After it seemed like the grit was breaking down, I refreshed the grit.  And then repeated as necessary.

I started with the Ultrafine.  This took a while, but it now seems to be very flat.  Yes - I can see a sliver of light under the steel ruler.  From experience, I know it does not take much of a gap to pass light.  My thinnest feeler gauge (0.0015 inches) is much too thick to pass under the ruler.  When I place the ruler over the gauge, the ruler can rock noticeably.

I then moved to the Medium, which was already fairly flat (dished about 0.0015 inches in the middle).  This did not take as long.  Judging by light passing under the ruler, it appears to be as flat as the Ultrafine.

I know Derek said he sees no light passing under the ruler when he checks his stones (in his post above).  I don't think I have ever seen anything so flat that it would not pass some light.  Time will tell if I have achieved flat enough.

Now that I think they are flat enough, I will have to use some finer grits to try to restore the original surface sheen.