Gap in Progression: Too much?

As someone else said here, or elsewheres: the thing that really matters is what you fininsh on.

Here is a progression I did as an experiment. It may need to be repeated, as the razor in the end did not keep a shave-ready edge, apparently there was something wrong with the temper/etc.

Anyhow, it does show the idea of what you finish on as having a strong effect on your final edge moreso than what you have in-between. Although perhaps the edge could have been more linear if smoother in-between hones were used? As I said, the wildcard in this experiment was that there was something not-right about that particular razor.

progression:

DMT1200
DMT8EE (8000)
Chromox on a hanging strop

All these images are at 200x

Seraphim, are those all taken at the same spot on the blade?

Quote:

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Originally Posted by holli4pirating

Seraphim, are those all taken at the same spot on the blade?

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That would be pretty difficult to do.

No they are not.

Quote:

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Originally Posted by Seraphim

That would be pretty difficult to do.

No they are not.

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Ok. Because, as we've all experienced, there can be inconsistencies along the edge when honing, so I would find it most interesting to see shots of the same part of the edge. I have no idea how one would go about doing that (I've not worked with such high magnification since high school biology), but there must be some way to mark the blade above the bevel or something...

Meh, still interesting photos that tell quite a bit.

Quote:

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Originally Posted by holli4pirating

Ok. Because, as we've all experienced, there can be inconsistencies along the edge when honing, so I would find it most interesting to see shots of the same part of the edge. I have no idea how one would go about doing that (I've not worked with such high magnification since high school biology), but there must be some way to mark the blade above the bevel or something...

Meh, still interesting photos that tell quite a bit.

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There IS a way to do it :)

Take a fine sharpie and put 2 marks like \ / on the blade just up above the bevel, then find that spot in the scope. Being away from the bevel, it shouldn't get wiped clean unless you have a heck of a slurry going on :)

I routinely use the 1200 to EE gap. About 20 laps on the EE will usually be enough to smooth out the 1200 marks, depending on the razor. Works fine.

My normal progression is DMT 1200 => DMT EE => barber hone/Thuringian/pink translucent Arkansas/Spyderco UF. Rarely, followed by 0.3u honing film or chrome oxide. Almost always ending with newspaper.

After considering things, I think we are asking the wrong question. We talk about grit, when what we should be discussing is the scratches. Seraphim's pics have emphasized this for me as well as my own fiddling around at 100x-200x.

Up to a certain point in our progression we are setting the bevel as Lynn stated. He does this at around 1000 grit. I think that means he has found the best combination of speed and ending up with a usable edge using this. If he used a coarser stone it might set the bevel faster, but the resulting scratches would take more time to get rid of on the next hone. If he used a higher grit, he would take more time getting the bevel set, but the scratches would be easier to get rid of at the next hone.

The next step in the progression is further sharpening AND getting rid of the scratches from the hone used to set the bevel. Going from the 1200 DMT to the 8000 DMT CAN be done because, for an 8000 git hone, the DMT is an aggressive cutter and using it will sharpen and smooth without a lot of extra strokes. Having used this progression, I can say it works. I have tried using a BBW between these steps and found it didn't make a whole lot of difference. That's not to say, you can't improve your progression, it means that I don't think the fineness of the grit tells the story of the problem.

As you go higher in grit the scratches become narrower. Through the "Sharpening" portion of the progression, this is mainly what one feels as improved cutting and increased comfort. Somewhere between 1200 and 8000 cutting stops being what we feel and becomes less important. From that point, the smoothness of the edge is what one feels. What happens from then on is polishing.

With microscopic images, I am seeing is deeper scratches from the DMT's than from the naturals. That means it takes more polishing to get rid of them.

I have found this discussed in a number of forums, and web pages that can be about sharpening tools, knives, swords, etc. One has to take into account that the goals of sharpening in other areas may be different (sharpness yes, but also durability, beauty, etc.).

But my synthesis of what I have read is that somewhere around 3000-4000 grit one moves from sharpening to polishing. This , of course, is much like Lynn has said. Also, because what you are doing has changed, so should the tool. At this point it becomes more important to get rid of the scratch pattern from the previous stage so you can move on to the next stage. The depth of the scratches becomes more important as you progress into higher degrees of polish. The argument is that the synthetics mostly cause deeper scratching and the naturals shallower.

In general, those who follow the Japanese style of sharpening advocate switching from synthetics to naturals in the 1000-4000 range. I don't know if this applies to all synthetics as the Super Stones or Chosera since I believe they are engineered to more closely emulate the sharpening from the naturals. I suspect it surely does include the DMT's.

So, from Japan Tool, has commented (I can't remember where, I ran into his posts regarding sharpening in a variety of forums as well as on his own site) that if he wants a really sharp result, he switches to naturals earlier (around 1000) because the shallower scratches permit him to get a sharper more durable edge. This was supplemented with some micrographs.

I have NO experience on which to base these conclusions - just my conclusions from my reading. I plan to experiment with using naturals after the 1200 DMT.

One thing that strikes me about Seraphim's photos is the difference between the last 2 pics. there are still deep appearing scratches from the DMT's that don't extend all the way to the edge. Probably because the strop works most strongly on the edge.

The jump is only from 9 micron to 3 micron. The 8000 mesh DMT is about the same abrasive size as a 4000 grit Japanese stone already. Personally, I would put another stone after the 8K, not before it.

Py, I think what you said about the BBW between the 1K and 8K DMT is interesting for two reasons. One is that it's very slow and the other is that, with just water, I think a BBW is right around the 8k mark but much smoother than the DMT. As such, if you go BBW to DMT 8k, you'll be at around the same grit, but your edge will be rougher. You were right on when you said that below that synthetics tend to scratch deeper than naturals. Scratches will also tend to get shallower as you move up, in addition to narrower.

I think a big part of the reason the Japanese switch from synthetics to naturals at a relatively low grit is that they have centuries of experience with naturals and know which ones are good. There was also a time when a statement like "all synthetics over 1k are terrible" was true, and I think there are still those who remember those times and continue with the same saying.