Santa brought me the 30,000 Shapton Glass stone. Here is a report from doing my first chisel. I took a 1” LN chisel that I had already “flattened” in the past and went through the whole sequence again. I did this because as I observed the back, I recognized that I really didn’t work that hard on it the first time I did it. The chisel has been wonderful as is, but I thought it deserved some more TLC. I started with 320 self adhesive sandpaper on one of those ludicrously flat granite blocks - just because there was a small spot where I had not gotten all the way out to the tip, nor had I worked as far towards the handle as I wanted to.
Then I went through a Shapton Glass stones, which were 1000, 4000, 8000, 16000, then 30,000. I worked the back for about 1 minute, then would re-flatten the stone on a DMT Dia-flat stone. I would work through the grits and reflagged each stone approximately 4-5 times before moving on the next grit. Then I worked the bevel side, with the LN honing guide quickly (20ish strokes per grit) all the way up to 30,000 at 35 degrees.
Conclusion, I am one of those dummies that likes to see that a blade can shave hairs, but I have never been able to sharpen where the blade can pop hairs off that are suspending (not having to cut at the base towards the skin). That chisel could cut every hair, as I hovered through them. I haven’t said “Wow” in a long time. I have no clue if this will retain an edge longer or if it makes a hill of beans difference on performance, but it was really cool to see. The back is probably 10-15% more mirror-like than a 16,000. I have a cheap jewelers loop and looked at the scratch patter at the cutting edge and there is a pretty decent difference between 30,000 and 16,000.
Is it worth the money…eh? I have about 50 tools to work through and a lot of projects to hopefully make throughout my life so time will tell. But since I have it - I’m glad I do. I hope this helps.