Vitrified Diamond #400 & #3000 Passaround

[Justinv]

Some more comments on the 3000 vitrified stone. I’ll address different topics from other posters. I'm not sure exactly what grit it is, I thought it felt coarser than 3000 but I don't know. It can make an excellent finished edge which is all that matters. I sharpened a variety of steels: Carbon steels Blue #1 and Blue #2, and several PM steels: SRS15, Hap40 (66 hrc), K390 (64 hrc), Rex-121 (67 hrc). Plus a few other basic stainless and carbon steels. I had no issue getting any steel paper towel slicing sharp. However this wasn't a magic stone that would get Rex-121 steel as screaming sharp as I can get Blue #1 steel. It works well as a 1 stone solution which is very convenient.

I observed the 3000 having a trait of getting a blade mostly sharp quickly, particularly with heavier pressure, but final edge refinement takes time. I noticed this being quite different from other stones I use where final refinement is faster. I have no idea why this differs, but I noticed on all steels including carbon steels. Maybe its just coarser than other stones I compared it to. My impression is that this stone can make excellent results but will take technique development and much time to master.

An annoying trait of the 3000 is the swarf on the stone is very abrasive and will abrade the finish in areas away from the edge. This is an issue with etched blades or anything with patina. I have etched blades that stayed perfect for years and then when I put them on this stone, it abraded the etching in spots. Some new shiny spots appeared that were as much as 1cm behind the edge despite these areas never touching the stone. Extra care on damascus blades is needed. Perhaps rinsing the stone and knife more frequently. I can post pictures if anyone is interested.

Something else I noticed is debris forms on the 3000 stone surface at times. Its like the little rubber bits that come off a pencil eraser. I think I noticed this on only one of the 400 grit stones, i’m not positive but I think it was the one with modified binder and I did not observe this on the hard or soft 400.

More comments to come…

 

[Justinv]

Some comments on the 400 grit diamond stones:

I had no use for these on edges as I have nothing chipped to repair. I only used the 400 grit for thinning.

My use of the three 400 grit stones was to just pick one up and grind some steel. All worked well. I had no issues with any of them loading. First task was a mono carbon-steel knife and I spent an hour or two on it. This steel is not the intended use but I wanted to evaluate them. I think I preferred the hard 400 over the modified binder version but they were not that different. I spent very little time with the modified binder stone. The soft 400 felt awesome but I'm not sure it was any faster. All of them just cut and any could get the job done. For this knife I also tried a shapton pro 220 grit stone. I think the shapton 220 was faster. To polish the scratches I went from the 400 grit diamond, to a shapton 1000, then went to the 3000 diamond. None of that was eventful and a final polish is still needed but that is for another day.

The next knife I tried was a better use. I thinned a wide bevel stainless clad hap40 knife with PM steel at about HRC66. I only had time to evaluate the hard 400 as it just went way faster than I expected. It just ate the stainless cladding and got business done. I had a zero grind with a burr forming in a few minutes. I cleaned up with a shapton 1000, diamond 3000, then finger stones. It went way faster than I expected and I never had a chance to compare the other 400 stones on this steel. For the edge I did a couple swipes on the 400 to remove the burr and make a small bevel and then finished it on the 3000 diamond. It ended up screaming sharp, easily pushcutting paper towels.

The soft 400 definitely felt different and I liked it. The hard 400 was the only one of the three that didn't absorb water which is nice. I don't think soaking for a couple minutes is a big deal before a thinning session that will take a while. I think I'd be fine with any of the three. For serious thinning of high carbide mono steels a lower grit would be nice.

 

[NickMinton]

Hey gang, giving the stones a whirl tonight (finally) after a really insane last week.

As others have mentioned, these things EAT metal! This was me doing some thinning and bevel work on a custom HVB.

Scratch pattern is after a total of 20-30 min on the different 400 stones, ending on the softer one

These stones have me really interested in getting a 220-400-800-1500 combo of some sort just to prep for polishing

These seriously cut down on the time needed to even out bevels for foundation work