Thread: Harshness and Final Bevel Shape

Originally Posted by Kingfish

Also, supporting the importance of having some degree of convex shape are some of the best razor honers using diamond spray on felt to finish off their bevels. Some of the naturals may also be creating a degree of convex bevel do to their slurries.
It now makes some sense to me that a perfect edge with no convex shape interacts with the skin giving a harsh shave. A convex shape, by whatever means created, makes contact with the skin at the same time as the edge supporting it and giving a smooth shave. Does that make sense?

My last word on this just to restate, microbevels were not even the main point of the post. Very few people can create a perfectly flat bevel on a flat hone even if they wanted to. Here are some reasons why:
1. Slurries pile up in front of blade, create convex shape.
2. Nervous system and skeletal system do not move in perfect lines, meaning that sometimes there is more pressure on the hone than others causing flex in blade, create convex shape.
3. Softer stones by their very nature give and release abrasives quickly, create convex shape.
4. Small imperfections on the surface of the hone contact leading edge first making it wear faster than behind, create convex shape.

If all the above factors are not valid, then my knowledge of sharpening is very flawed.(it could be)

Other factors that honers indulge in frequently also create convex shapes after razor is honed by stropping. Please, for me this is all in good fun, I made an observation, reported it and still am not trying to draw an elaborate conclusion, and if it came off that way, shame on me.
Mike

Last word; ohhh. Never
Matte Surface Mystery « The Sharpening Blog

be sure to continue on to part 2.

Originally Posted by kevint

Last word; ohhh. Never
Matte Surface Mystery « The Sharpening Blog

be sure to continue on to part 2.

Interesting read. So Harellson told Ron Hock that, “the very best natural waterstones top out at about 10,000 to 12,000 grit”. I am surprised at that having heard so much about the fabled J-nats going well beyond even the Shapton 30k. Of course that is only one man's opinion.

Edit, Kevin, I had to work to find part 2 here but glad I did. The natural edge looks 'better' to me at 3,000x. I wonder how the one will hold up as opposed to the other ?

Originally Posted by JimmyHAD

Interesting read. So Harellson told Ron Hock that, “the very best natural waterstones top out at about 10,000 to 12,000 grit”. I am surprised at that having heard so much about the fabled J-nats going well beyond even the Shapton 30k. Of course that is only one man's opinion.

Edit, Kevin, I had to work to find part 2 here but glad I did. The natural edge looks 'better' to me at 3,000x. I wonder how the one will hold up as opposed to the other ?

Are the stones used for woodworking tools the same as the stones used for razors? I am not convinced that a chisel needs to be finished on a razor quality stone to do its job properly, may be I am wrong

Originally Posted by mainaman

Are the stones used for woodworking tools the same as the stones used for razors? I am not convinced that a chisel needs to be finished on a razor quality stone to do its job properly, may be I am wrong

I know no more than you on the woodworking but the synthetic stones that we use to hone our razors, Shaptons, Nortons, Naniwas etcetera are made for woodworkers. We have adapted them to our pursuit and since steel is basically steel they work well..... IMO.

Originally Posted by JimmyHAD

I know no more than you on the woodworking but the synthetic stones that we use to hone our razors, Shaptons, Nortons, Naniwas etcetera are made for woodworkers. We have adapted them to our pursuit and since steel is basically steel they work well..... IMO.

What makes me suspicious is the fact that they have a grit rating for the nat stone.

Originally Posted by mainaman

Are the stones used for woodworking tools the same as the stones used for razors? I am not convinced that a chisel needs to be finished on a razor quality stone to do its job properly, may be I am wrong

It depends; so the answer is sometimes yes sometimes no. Most of the time an 8k edge is all one needs. Sometimes even a 5 or 1k is enough.

If you use the natural surface of the wood without any sort of protective finish, as in traditional architecture of Japan you want that to be very smooth. Not only does it create a natural shine, it weathers far better that say a 320(++++) grit sanded surface (or more coarsely planned)

As well using soft wood requires a much more refined edge than what is typically required for hard wood.

Originally Posted by kevint

It depends; so the answer is sometimes yes sometimes no. Most of the time an 8k edge is all one needs. Sometimes even a 5 or 1k is enough.

If you use the natural surface of the wood without any sort of protective finish, as in traditional architecture of Japan you want that to be very smooth. Not only does it create a natural shine, it weathers far better that say a 320(++++) grit sanded surface (or more coarsely planned)

As well using soft wood requires a much more refined edge than what is typically required for hard wood.

Thanks,

I am not sure what type of finsih is needed for a chisel/ plane to get the best of it in the most demanding situation. There are fine finishers such as what we use for razors , and then there are medium finishers, which are finer than 10k (I have one of those) but nowhere near a quality Asagi. In that blog there is no mention of what type of stone has been used, I wish they were more specific, because their statement is pretty bold.

Originally Posted by mainaman

Thanks,

I am not sure what type of finsih is needed for a chisel/ plane to get the best of it in the most demanding situation. There are fine finishers such as what we use for razors , and then there are medium finishers, which are finer than 10k (I have one of those) but nowhere near a quality Asagi. In that blog there is no mention of what type of stone has been used, I wish they were more specific, because their statement is pretty bold.

By boldness I asume you mean the grit. That it was stated to be around 12k or HStanley reporting that nat abrasive tops out at such a low figure. One of those perhaps.

You can follow or add to some more discussion of the blog at japansestoolsdotcom forum.

Personally I am happy when i can improve the edge given by my coticule. That happens off my suita and again from asagi. I dont have synthetics of sure grit to know whether i can tell the difference between 12, 16, 30k. But I have nats that may (or maybe not) in that range.
I think I know) that a hard stone like an Escher or Asagi give a super smooth edge. Whether this is a result of very minimal slurrying or an ultimate fine grit rating I am unsure. I have seen Escher's rated at 12k on the conservative end. Asagi sometimes nearer 45k than 30. But I think it entirely possible if we could find an asagi singular grit it may well measure 10-16k shapton particle size-which is not the important thing.
In the end what we get depends a great deal on the razor. Ultimately I accept the fact that I dont know what finish is needed to get the best of it in the most demanding situation, even though i go on and on. I am my own biggest variable, so I do what I can, hoping for better than last time.

Originally Posted by mainaman

Thanks,

I am not sure what type of finsih is needed for a chisel/ plane to get the best of it in the most demanding situation. There are fine finishers such as what we use for razors , and then there are medium finishers, which are finer than 10k (I have one of those) but nowhere near a quality Asagi. In that blog there is no mention of what type of stone has been used, I wish they were more specific, because their statement is pretty bold.

I asked So what he thinks of the post in that blog, after ll he probably has dealt with more Natural stones that the combined membership of the forum, here is his answer:

Konrad's stone is actually from me (his friend got it from me and sent it to him as a gift), an Okudo Suita. It is about #22000~25000 in my opinion. So the finest ones are even finer, but because woodworking tools don't need such keen edge, I recommended Okudo because they are fine enough and very fast.

Fineness judgment is very tricky, because many factors are involved. Easiest to understand situation is when the honer has not yet pulled out the max potential of the stone, then of course the finish will be coarser than the potential. Also, I'm pretty sure that these guys haven't experienced fully all the natural stones. So, it could just be that they don't know yet.