Thread: How sharp is sharp?

Originally Posted by Steel

Look at the persons post who you want to reply directly to and in the bottom right corner of their post you will see a button "Reply With Quote". Tap that and it will open a box with their post already copied and within quotations. You can then type your reply before or after their quoted post. Hope this helps.

Thanks Steel, much appreciated.

Originally Posted by BobH

There obviously should be a point past which you can't make a razor any sharper. I would bet for most people that before you reached that point the razor would become uncomfortable to shave with. So really it does not matter if you can eke out the last bit of sharpness from a blade or not because it probably would not be usable.

I think Jimmy alluded to it in his post when he said "That razor got so sharp by the time I got done that you touched it to your cheek with any pressure/carelessness and you were cut. That is probably the sharpest I ever got a razor. Very like a Feather DE blade and I'll never deliberately do that again." To me that is way past the sharp you need for a smooth comfortable shave.

At the bottom of the post you want to quote there is a reply with quote option if that is what you mean.

Bob

Doesn't matter to you Bob, but the way I figure it, first you need to work out how to get a razor as sharp as it is possible to get it. After you've achieved that you can control how blunt you want it, but not the other way around. Thanks for showing me how to reply with a quote, much appreciated, kind regards.

In the metallurgical sense, the limit for "sharpness" has to do with the types of carbides (of course including composition), and their sizes. Or their size in the metallic structure, if it does not contain Carbon, or Iron.
Generally, a martensite rich structure can offer a sharper edge than perlite, ferrite austenite etc. For that, carbon content and heat treatment are the most important factors.
A piece of plain iron, no matter how you sharpen it, WILL NOT shave. I have tried it many times. It will feel sharp but won't shave.
For the elements that are added to the steel, the smallest the crystals they form with Carbon, the sharper and less brittle the edge will be, generally. Chromium forms large crystals. Vanadium forms one of the smallest, if not the smallest.
And, the purer the steel from unwanted elements it is, like Sulfur and Phosphorus, the better. On everything.
I'm sure there are people who know more about the details, but that's my understanding on how things work.

For me, too sharp is when I get weepers, my face bleeds tiny spots on my face, not cuts just imperfections on my face weep blood. A cold water rinse usually stops them. That and the shave is uncomfortable, my skin burns after shaving. The edge is so sharp it is removing skin, we are always removing some skin, but here another layer is removed.

After a shave like that, I look at the edge under magnification and if there is no micro chipping, the edge is just too sharp. Stropping on plain leather or linen will dull the edge enough to make comfortable again. If not some .50 Diamond laps will.

I have experimented with paste and found for me excessive laps stropping on some paste can easily develop such an edge, on some razors.

The weird thing is, too sharp for me, may be just fine for you.

Originally Posted by Euclid440

For me, too sharp is when I get weepers, my face bleeds tiny spots on my face, not cuts just imperfections on my face weep blood. A cold water rinse usually stops them. That and the shave is uncomfortable, my skin burns after shaving. The edge is so sharp it is removing skin, we are always removing some skin, but here another layer is removed.

After a shave like that, I look at the edge under magnification and if there is no micro chipping, the edge is just too sharp. Stropping on plain leather or linen will dull the edge enough to make comfortable again. If not some .50 Diamond laps will.

I have experimented with paste and found for me excessive laps stropping on some paste can easily develop such an edge, on some razors.

The weird thing is, too sharp for me, may be just fine for you.

Yes sir, just keep improving the edge till it gets unbearable to your face and back off two strokes. That is not a universal standard as every ones face is different. There really is no way to answer the OPs question in any practical way. I mean how far is infinity?

Bob

Originally Posted by Geezer

Sharp is formed at the lower grit stones, all later stones do is polish the bevel of that sharpness and make a smoother edge.

Originally Posted by puketui41

and WOW! smoothest shave I've ever had. I only needed one pass to get BBS.

Notice something there ???

Looking at the upper limit of sharp isnt important to me. Whats more important imois if its sharp enough. Shave technique will allow you to increase an edges cutting power with a slicing stroke. Im not talking about using a dull edge now. But being able to use a plenty sharp edge the right way with proper prep and technique. If you can get a bbs shave from one, its definitely sharp enough. Dont let me rain on your parade gentlemen. I went through a similar phase a while ago. Endless quest for super sharp came with weepers and irritation. Im a happy man now. Lol.

No doubt the 1K stone does 95 percent of the sharpening as well as flatten the bevels and produce a straight edge. The other hones polish the bevel by removing the deep 1K stria with progressively finer stria and a less serrated edge making a smoother shaving edge and possibly adding 1-2 percent of sharpness.

When I began experimenting with paste several years ago, my theory was, if the stria was finer the edge would be straighter, less serrated and smoother. I was after the elusive squeegee smooth shave.

I thought if one removed all the visible stria, (at 400X magnification) the edge would be straighter and smoother… and it is, up to a point. But it also thins, lengthens and sharpens the edge somewhat, perhaps that elusive 2-3 percent. Some blades can take it, some can’t.

You can test this yourself fairly easily. Chrome, Cerium, Ferrous Oxide and High grit Diamond and CBN will remove all visible stria from a bevel. So will fine metal polish, MAAS and Semi Chrome, as well some others. The Oxides will take many laps 2-300, Diamond and CBN less so. Metal polish about 2-300. Depending on your level of polish with your finishing stone, it may take more or less laps.

You can make a 12 X 3 in paddle strop from 4mm Craft Foam or Foam Core Poster board or fine weave Nylon Strapping for a hanging strop and some metal polish.

This is also a good test of your honing. My goal in honing, after bevel setting, is to remove the stria of the previous stone with each progressive stone. 4k removes 1k, 8k removes 4K.

If you polish out the stria, you will see any deep stria you did not remove, as the finer stria is removed first. That deep stria will result in a microscopic chip at the edge.

Now I am not saying, you do have to remove all the stria to get a good shaveable edge, this is just an experiment.

What I found is stropping to this extreme also can, on some blades sharpen/polish the edge to an uncomfortable level, for me causing weepers and uncomfortable harsh edge. The only paste/spray that does not cause this is CBN, it will remove all stria.

So while pasting is done for comfort, too much or to excess can go over the line.

Try it, see what happens. At the least you may learn something about your honing technique.

If you can achieve excess, you can dial it down to a level that is best for you. You do not have to strop to this level to get a BBS shave, you just have to get the edge to a level that works for your face, however that is for you.

Let’s face it 99 percent of my shaves are “Get out the door shaves”.

Not looking for an argument but, I dont think you can have a bevel scratch free with plenty of light from multiple angles. You can manipulate the light and viewing angle somewhat, but that doesnt mean theyre not there. The absence of scratches at all would mean a perfect mirror. Would love to see some photos of these at multiple angles and with ample light. Of course I am talking about at 400x or even 200x.

Originally Posted by Euclid440

No doubt the 1K stone does 95 percent of the sharpening as well as flatten the bevels and produce a straight edge. The other hones polish the bevel by removing the deep 1K stria with progressively finer stria and a less serrated edge making a smoother shaving edge and possibly adding 1-2 percent of sharpness.

When I began experimenting with paste several years ago, my theory was, if the stria was finer the edge would be straighter, less serrated and smoother. I was after the elusive squeegee smooth shave.

I thought if one removed all the visible stria, (at 400X magnification) the edge would be straighter and smoother… and it is, up to a point. But it also thins, lengthens and sharpens the edge somewhat, perhaps that elusive 2-3 percent. Some blades can take it, some can’t.

You can test this yourself fairly easily. Chrome, Cerium, Ferrous Oxide and High grit Diamond and CBN will remove all visible stria from a bevel. So will fine metal polish, MAAS and Semi Chrome, as well some others. The Oxides will take many laps 2-300, Diamond and CBN less so. Metal polish about 2-300. Depending on your level of polish with your finishing stone, it may take more or less laps.

You can make a 12 X 3 in paddle strop from 4mm Craft Foam or Foam Core Poster board or fine weave Nylon Strapping for a hanging strop and some metal polish.

This is also a good test of your honing. My goal in honing, after bevel setting, is to remove the stria of the previous stone with each progressive stone. 4k removes 1k, 8k removes 4K.

If you polish out the stria, you will see any deep stria you did not remove, as the finer stria is removed first. That deep stria will result in a microscopic chip at the edge.

Now I am not saying, you do have to remove all the stria to get a good shaveable edge, this is just an experiment.

What I found is stropping to this extreme also can, on some blades sharpen/polish the edge to an uncomfortable level, for me causing weepers and uncomfortable harsh edge. The only paste/spray that does not cause this is CBN, it will remove all stria.

So while pasting is done for comfort, too much or to excess can go over the line.

Try it, see what happens. At the least you may learn something about your honing technique.

If you can achieve excess, you can dial it down to a level that is best for you. You do not have to strop to this level to get a BBS shave, you just have to get the edge to a level that works for your face, however that is for you.

Let’s face it 99 percent of my shaves are “Get out the door shaves”.

On that, I have to add,,, seriously man, stria? C'mon! It doesn't even mean "underhoning" or "micro-serrations" or "overhoning-wire edge". I know it sounds cool like all Latin and Greek based words, but keep geology out of this.
It would be bad if "edge imperfections" were named "stria".
Think about it; if you saw a thread with content "I don't know what to do about the striae of my edge that doesn't shave" how would you answer?