[OP]
Member
OK, I know my King waterstones aren't really defective. However, I simply cannot get a mirror shine from my G-1 (8000 grit). I clean it, flatten it, use a nagura, don't use a nagura. Everything I can think of. My chisels and plane blades never get a mirror shine.
That being said, I have a Norton 8000 stone at work that I can get a mirror shine with.
What's up??? I'm at a complete loss here.
Member
I have had this same problem. I was fortunate enough to have gone to visit Gary Rogowski in Portland, and be the subject of "A trip to the sharpening doctor" for Fine Woodworking.
During our 2 days, Gary was able to get a mirror polish on his King 6000, while my Norton 8000 left a dull "polish".
Gary recommended, and I am now using "Herb's Yellowstone" Honing compound, available from Craftsman Studios. It gave me a great polish using it on a leather strop.
My input? Sometimes you may get the shine, light touch, more fine particles, etc. When on that file a stone, the edge will work well, regardless of polish. A final stropping will shine it the way you like it.
Member
As you finish polishing, let the stone start to go dry. It will turn black from the steel remaining on the surface of the stone. A few strokes more and you will be polishing "steel on steel". (It is interesting to note that natural stones often will not polish as bright as the synthetic stones. Different stones have different qualities and may not yield exactly the same result.) If you still don't get a mirror finish, you may not be getting all of the coarser scratches out. What is the grit of the previous stone? BTW, the nagura is only used at the start to bring up a slurry.
David DeCristoforo
Contributor
The thing to worry about is whether your tools are sharp and performing well, and not whether they shine or not. If the shine is important to you, get some green honing compound - you can get it at your local wood store (I get it at Woodcraft) - and use that on leather or just on MDF. That will put a shine on your tool bevels.
The green honing compound is cheap. I buy it in large bars because I use it on my carving tools, and I think I pay about $10 for the bar. A large bar lasts me for years and I use it a lot. If you only use it on plane blades and chisels, a large bar is probably a lifetime supply.
Mike
[Attached is a picture of the large bar of green honing compound. I included the glasses just to give a size perspective. This bar is partially used.]
Last edited by Mike Henderson; 03-09-2009 at 9:26 PM.
Go into the world and do well. But more importantly, go into the world and do good.
Member
I know some will look at this as heresy, but a mirror shine does not equal sharp. So don't worry about it.What you want is a clean intersection of the back and bevel of your tool.
Here's a picture of a ridiculously sharp Japanese chisel (not mine, though). Clearly, there isn't a mirror finish on it.
In fact, Japanese tools have a well-deserved reputation for having extreme sharpness, but overall they do not have that highly polished appearance that is seen more often in western tools.
I've used natural Japanese waterstones and Shaptons. Both will give me a very sharp edge, but the Shaptons will give me a shinier surface than the natural waterstones, on both western and Japanese tools. Since both types of waterstones will give me very sharp edges, I've come to believe that a mirror finish has nothing to do with it.
[OP]
Member
I do realize that mirror doesn't equal sharp and a non-mirror can be lethally sharp. However, and I should have stated this earlier, my tools certainly get sharper on the Norton than on the King stone.
Member
That is a weird issue on a man-made stone, especially that fine in grit. I have yet to see a synthetic waterstone over 8000g that wouldn't produce a mirror finish, even with scratches from 1-2 stones prior. Either your technique could use some improvement or you could in fact have a defective stone. It isn't unheard of to have a stone batch get contaminated.
Originally Posted by James Carmichael
Member
While I agree in principle, the mirror provided by the highest stone can serve as a good indicator of whether you have finished with the last stone. For me, I have a 4000/8000 Norton, and the 4000 leaves a grey finish, while the 8000 a mirror. That mirror lets me know when I am getting close to finished, then I remove the burr. done.
Member
I am certain that a shiny edge is a sharper edge. The absence of a polished surface indicates a surface of micro scratches. The edge needs to be as free of scratches as possible. The term razor sharp is somewhat open to personal interpretation. That is a problem here. Look at the edge of a razor blade. You will never see one that has a dull finished edge. That should tell something.
Member
Here's another picture. This is one of my Japanese chisels, which does not have a mirror polish. Next to it is an end grain pine shaving I made with it.
If mirror polish is all there was to it, we'd all be singing the praises of Two Cherries bench chisels.
I think that mirror polish is a result of a very even scratch pattern, and is not an absolute measure of sharpness itself. Probably what is happening with natural Japanese waterstones is that you get a spread of scratches, which results in a matte finish on the tool, but the range of the sizes of the scratches is smaller than the scratches that you would get on, say, an 8000 grit man made waterstone, so the edge is at least as sharp as that coming off of an 8000 grit Norton.
Just to clarify: I do think you can get very sharp edges with tools with a mirror finish as well. It's just that there is more to getting a sharp edge than a mirror finish, and with certain sharpening methods, a mirror finish seems to be unnecessary for a sharp edge.
Last edited by Wilbur Pan; 03-10-2009 at 9:43 PM.
Member
High polish is not all there is to it. Polish gotten by buffing is apt to be too rounded and blunt an edge. I only advocate a last stroping which maintains the acute edge,not excessive polishing such as you see on factory edges of some chisels and carving tools. It cannot be logical to deny that a polished edge is less serrated than a matte edge. If applied correctly,it will give a smoother microscopic edge that is also acute as it should be.
On the other hand,if you are happy with whatever edge you have,by all means use it.
Member
It is completely logical that a matte edge can be sharper than a polished edge.
If the polished edge has even scratches of 1 micron, and the matte edge has a range of scratch sizes ranging from 0.1 micron to 0.5 micron, then the matte edge will have a sharper edge, as all the scratches are still smaller than the tool with the polished edge.
Member
Why are all razor blades mirror polished on their edges? Surgical instruments also.How much time and development in a competetive market has been spent on these type of items,where the smoothest and most comfortable shaves will win the customers? How are you measuring your microns? I do not advocate high polish with deep scratches.That is not finished craftsmanship. Only high polish with no scratches.
Obviously,a matte chisel can cut. It is a matter of degrees which will cut the smoothest.
Last edited by george wilson; 03-10-2009 at 10:35 PM.
Contributor
Could I throw a question in here?
"How many angels can dance on the head of a pin?"
Mike
Go into the world and do well. But more importantly, go into the world and do good.
Member
It's not that esoteric,Mike,though I agree it is similar to many discussions that seem to go around and around,in spite of real and logical evidences that are presented.
As a machinist,I use gage blocks,which are accurate to millionths of an inch. Their surfaces are lapped to extremely flat and polished degrees so that they will stick together as if they were magnetized,but are not. They would not behave this way,or be as accurate with matte,unfinished surfaces.It should be abundantly clear that a polished surface is smoother than a matte one.
It is not logical to say that a polished edge will be less smooth than a matte edge.
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