Cnat (Adaee #12000) -v- Hard Black Arkansas Using Very Hard Stainless Steel SRs

[Chandu]

I dressed all the stones with my Atoma 600 and still resulted in different resistance on the surface.

I can see that happening. Stones have different hardnesses and grit sizes. Diamond trumps anything they are made of, but how deep it digs and the resultant surface is going to be different depending on if something is made of something like garnet or novaculite or whatever else.

Then too as soon as you use the newly 600 grit diamond lapped stones they start to change because they wear. Even when we try to make things identical, we largely can't.

 

[Chandu]

Tomorrow I will start comparing the black Ark against my Adaee #12000 Cnat with my hardest-steel SRs, the Titan ACRO T.H-70.

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Both SRs are of Japanese stainless steel having a hardness in the late 60s RHC and were refined on lapping films of 5μm, 3μm and 1μm. The black tail was then finished on the black Ark and the green tail finished on the Adaee #12000. Both whetstones are very hard and slow "cutters" (probably better described as slow polishers). Surprisingly both stones have similar densities of 2.72 (Ark) and 2.77 (Cnat) although of course they have different mineralogical properties.

For finishing, each SR was given (without slurry) about 400 laps with water followed by about 200 laps with lather (I told you they were slow), all using just the mass of the blade as pressure. Lapping with lather was finished with a few short X strokes.

I will report back here with my observations during the week.

I have never tried the RHC, but someday I might. I have a 12x3x1 Dan's Hard Black that I have never used. I might sit on it as an investment. Honestly, if you look at what Arks have done price wise, it probably isn't a terrible idea. I could get the RCH and have the same result on my edges.

I did recently pick up one of the last Norton 8x2x3/4 Translucents. Its a different machine than Dan's Translucent. Dans is finer at least in how it's cut. Will be interesting to see how the Norton goes over time. I have a small slip stone type of Norton Translucent from my grandfather that had the little grooves in it for sharpening dental tools and other things and it's much finer than the Norton bench stone.

 

[SliceOfLife]

I don't think you're gonna do anything to a Dans Hard Black that's gonna hurt its value (unless you drop it).

The later era Norton translucents I've owned were faster stones than real old vintages. Is it the stone or is it years of the surface being worked to take all the tooth out of it... that's the question.

 

[Chandu]

Is it the stone or is it years of the surface being worked to take all the tooth out of it... that's the question.

That is my exact thought. I think the answer might be both. I would say just as we know washita varies a lot in quality etc, so could translucent or other grades too.

 

[rbscebu]

Over the past week or so I have been trying to max out the Titan ACRO T.H-60 (black tail) on the HBA. I was seeing how keen I could get the edge, ignoring shave comfort. For about 6 or 7 days of lightly refreshing the edge after each daily shave, I reach a plateau where I noticed no further improvement in the edge's keenness.

I then spent a few more days shaving with this SR without is touching the HBA. I was a little surprised that the shaves were becoming more comfortable with what I thought was no loss of keenness.

This morning I did another comparison shave with the two T.H-70 SRs. The Adaee (green tail) SR had not been touched since the last comparison shave between the two.

From this morning's comparison, I found that the Adaee SR still had more keenness in its edge than the HBA SR but the HBA SR was definitely the more comfortable to shave with, except when performing my CdM.

I might try this again one day but the opposite way around, maxing out the Adaee SR and then seeing if it becomes more comfortable without refreshing.

Natural stones can be fun and interesting.

 

[Steve56]

From this morning's comparison, I found that the Adaee SR still had more keenness in its edge than the HBA SR but the HBA SR was definitely the more comfortable to shave with, except when performing my CdM.

If it feels sharp, it’s dull. If it feels dull, it’s sharp.

 

[Wid]

If it feels sharp, it’s dull. If it feels dull, it’s sharp.

Never really thought about it in this way but it’s a fact.

 

[rbscebu]

If it feels sharp, it’s dull. If it feels dull, it’s sharp.

Very true, particularly when performing the CdM.

 

[Mitzie]

Don't SRs like to be rested, hence the reason for seven day sets in the old days?

 

[rbscebu]

Don't SRs like to be rested, hence the reason for seven day sets in the old days?

Yes, very true. It was the custom for centuries to rest your SR for a few days or more between each shave. It was in 1911 when Dovo did a thorough peer-reviewed scientific study. That study determined to most effective rest period for carbon steel SRs was 35 hours 19 minutes.

In 1932 Dovo did a further scientific study that found "safety" razors also benefited from a rest period, with the most effective period being 27 hours 42 minutes. (No mention was made of a rest period for the blade.)

Unfortunately I left the study's technical report in Cebu when I moved to Australia .

So far, I know of no definitive scientific study covering a rest period for a stainless steel SR. However, due to Dovo's findings above, I try to rest my stainless steel SRs for at least 23 hours 14 minutes (because it sounds about right ).