I just bought a set of Japanese waterstones (250,1000,4000 & 8000). After going through the sequance I noticed that the blade wasn't that polished in that I couldn't exactly count nosehairs, as I could with scary sharp. I did a few laps then on 1000 and 2000 wet/dry, and my edge was a mirror.
Now my question, is it my technique, or is 8000 on a waterstone not fine enough?
TIA Glen
"Sharp" is measured by cutting ability, not shine. I use a ceramic stone followed by black arkansas for finishing. I tried scary sharp and the result sure looked pretty but didn't cut very well. A few strokes on the black arkansas took some of the shine off but the cutting ability was back.
8000 on a waterstone is fine enough for just about any purpose--after that hone with a strop if you need sharper.Strop with Chromium oxide after a fine Arkansas and count all the hairs you want.
How's the edge work?
Hey Glen,
The 8k should be adequate for a mirror smooth polished blade. What type of steel blade are you working? Some take longer than others to tune (eg carbon vs cryo).
Cheers and good luck,
aw
4000 on a waterstone should be a mirror (although I go to 8000 for woodworking tools).
Fine waterstones are usually hard, which means that they don't easily generate a sluury, and it's the slurry that does the work. Are you using a nagura stone to build this up before honing ?
A new synthetic waterstone may also have a surface "skin" to it. They may even have had a glue-based size applied deliberately - especially those that are then signed with a brush. It can take a little use before they really start to work properly. I've stones that work OK without a nagura now, but they needed one to begin with.
Thirdly, forget worrying too much about the mirror - it's not the shine that cuts, it's the edge.
Do shine and edge not go together, regardless the technique?
It is my understanding that the more flat and smooth the two surfaces are that meet to form an edge, the stronger and sharper that edge. While our goal is to get a good sharp edge, not mirrored surfaces, one begets the other.
/rick.
A ball bearing is pretty shiny, but cuts poorly.
Handsome is/handsome does.
Good Golly, I am out of my league here, but:
I thought for plane blades, we were to use dual edge bevels. Did this change?
The micro-edge bevel was supposed to be for quick touch up sharpening. No matter how sharp you start out with, it is going to get dull, and with a second micro- bevel you can get a quicker edge than polishing the entire bevel.
Again, did this change?
Phil S.
Well, I did say " and smooth" (emphasis added).
But you do raise a valid point; a point that makes me somewhat skeptical of claims that the Scary Sharp sandpaper on glass method is at least as good as waterstones. While Scary Sharp will result in mirrored surfaces, I remain concerned that the padding of the paper under the abrasive produces a very slight "curved hill" right at the very edge of the iron/chisel, which would likely be most pronounced while honing the microbevel (since such a small surface is "digging" into the sandpaper, thereby producing a bigger hill -- or valley, if you prefer).
The action of this hill on the edge will not produce your ball bearing, but it must be somewhat curving the bevel (and the flat side of the iron to a lesser degree) right at the point of the edge, deterring sharpness.
I would think the hard, flat, non-giving surfaces of waterstones would contribute to sharper, better cutting edges.
(Despite all this, I continue to use sandpaper on glass -- since it is much cheaper than the cost of good high grit waterstones -- and I have been getting results that are at least satisfactory for my needs.)
/rick.
Shiny != flat. I remember a couple of students trying to make optical flats. One was getting them incredibly shiny but the interference patterns were all over the place. The other wasn't getting so shiny but his interference patterns were nearly perfect.
First you want the edges to meet at the right angle, then you want them flat, then you want them smooth IMO.
No.
The microbevel, while very, very thin, is still hopefully a flat, smooth (and therefore shiny) surface.
/rick.
it applies to some blades more than others....
Of course, I was tweaking about the word shine, which is why I used it.
I've been using Arkansas and ceramics forever, because I do most of my honing on carving tools, which are not likely to keep waterstones flat for plane irons. Most important is to clear the wire edge. Finer hone and a quick rap into a piece of pine can do it, but the shiniest bevel suffers if the slip isn't applied, or the back of the iron lapped.
Bet I've spent less overall in the last 20 years or so than you have on sandpaper, though. Haven't thrown any of my four stones away.
You are probably right, George.
All else being equal (which they are actually not since I have only been in this game for a short time -- certainly much less than your 20 years), the sandpaper replacement costs do add up. But I look at $50-70 for a 8000 grit stone against $3 for a small pack of 2000 grit wet/dry, and I go the cheap route. I never was very good at investments.
/rick.
An alternative to a fine stone for finishing an edge is the green honing compound from Lee Valley. Rub some compound on a flat, smooth hardwood block much the way some use diamond paste, and use that as a sharpening stone. I've been using this since December with great results - I usually start with 1 000 grit, then 4 000, maybe 6 000, and for something I want to sing, the honing compound. Thanks to Ben and Doug at Shepherd Tools for this tip.
Jeffo
Take up sword polishing. I realised I'd spent more on a stone than I paid for a Norris plane !
No, only if the technique is right,.
For one thing, I can easily give you a mirrored bevel on an old refurbished chisel. But if I didn't flatten the rust-pitted back properly, the edge will be rubbish.
but it does work ; ^ >
yes the paper does have some give in it. not much, but more than the stone. under the microscope I'd ecpect to see the last few thousandths to be at yet *another* microbevel (submicrobevel?)
Been using Chromium Oxide for almost 20 years. My carving teacher favored it. It also works well on a powered disk or a felt wheel.
No. Shine and edge sharpness are not related. Once I used Scary Sharp to re-establish the edge of my plane irons. When I got up to 600 grit I noticed the edge was taking on a nice polish. Then, when I went over to my waterstones to hone I noticed the edge on the 4000 grit stone wasn't nearly as shiny as the 600 grit sandpaper but, the 4000 grit stone was much more sharp.
I surmised that the slurry of tiny metal particles and the quick dulling of the aluminum oxide sandpaper contributed to the polishing effect of Scary Sharp. FWIW, once I'm done honing on my 8000 grit stone the edge looks like chrome and can shave off the fine hairs on my knuckles. My chisels and plane irons are so sharp I've often cut or knicked myself while hoing without even knowing!
Layne
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