So I've seen this 30,000 grit waterstone floating around the web lately. Anybody use one? Is it really worth 300 bones? What grit to most people use otherwise? I dont see more than 8000 most of the time, though Shapton makes a 16000 as well.
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Member
So I've seen this 30,000 grit waterstone floating around the web lately. Anybody use one? Is it really worth 300 bones? What grit to most people use otherwise? I dont see more than 8000 most of the time, though Shapton makes a 16000 as well.
Member
I use a 1000/8000 Norton for all my honing. Haven't found a need for anything above 8000. I think some people even stop at 6000. I've heard the Shapton's are great, but don't specifically know anything about the 16,000 or 30,000. Curious to hear what others think.
Guest
I have used the 16000 (two of them now) and 30000 glasstones, and in my opinion, the answer is no.Originally Posted by Bobby O'Neal
The 16000 glasstone a very fine stone, fine enough that you really aren't going to have a wire edge to deal with even on A2.
I also can't tell the difference between a surface planed with a 30k stone and a 16k stone, even when looking across the board into a light source.
If you want to go finer than a 16k glasstone, put down green chromium oxide stuff on a strip of 3/4" MDF that you cut into a piece roughly the size of a large honing stone, and lubricate with a little bit of light mineral oil (that takes some of the aggression out of it). The edge will be every bit as good as the 30k stone and the total cost will be about $15.
I use such a strip as my strop for chisels, and it lets you strop with your sharpening technique, so you don't lose geometry of the edge.
I know that the buddy of mine who bought the 30k stone wouldn't buy one again. Curiosity killed him and he just wanted to try it. I didn't really discourage it at the time either, because I also wanted to try it, just not on my own dime.
Member
Up to 16000 (basically 1000 and 16000) hit my blades. I took a Cosman class a while back and he used 30000 and was impressed by it. I don't think the big sell was in the quality of cut but the edge retention. A 30000 blade will hold an edge longer. Is it worth it? Only you can judge that. For a hobbyist woodworker who doesn't sharpen but once a weekend (or longer) I would say no. However, if you are going to your stones several times a day it may be worth it over the long run. What is 300 bones worth to you? How much is your time worth? I do know it will probably last a lifetime.
With skill and tool we put our trust and when that won't do then power we must.
Guest
I think that there needs to be a stroke test before we start describing the edge retention as that much longer. It may be that 30 strokes across a board degrades a 30k edge to where a 16k edge would be, and it may be less than that.
With a new-as-of-last-year LN iron, it took me 1100 strokes across the edge of a hard maple board 18 inches long with a .002" shaving before the plane decided to no longer cut.
I think the difference for edge retention between .9 micron particles and .5 micron particles is way overstated, and I probably wouldn't believe that there was a material difference without doing the test myself, and i'm not about to take 2200 more strokes across a maple board to find out when even if it is better, an MDF strop with green stuff will get you to the same level of sharpness for $10-$15, and with a better freehand feel than the fine shaptons.
Member
Why is this? I know when I sharpen my kitchen knives to a finer grit (done with a belt grinder, usually) they seem to dull more quickly. I know the conventional wisdom for turning tools is much the same--finer edge will dull more quickly.
I've heretofore sharpened with 3m microabrasives and a granite machinist's plate, but I just ordered a set of 2k, 5k and 8k shaptons. I decided to pass on the 16k because I figured that if 8k is fine enough for Christopher Schwarz and the folks at Lie-Nielsen then it should be fine enough for me.
Guest
One aside, there are other things that determine edge retention more predictably at that level of sharpness than 0.9 to 0.5 micron. First and foremost, good quality steel that's properly heat treated.
When I was pushing around A2 irons, the order of durability went directly with which iron was going to be first to let go of some carbides and leave lines on the work. If an iron let go of a few around 200 strokes or so, and a lot of them do, you start seeing tiny lines in the work. Guaranteed the iron will not last 1100 strokes like the one I mentioned above, no matter what stone is started with.
On the flip side, if the steel is high carbon, and it's good quality, it should wear more evenly, but it will wear more quickly. The wear bevel will be longer, and you'll run the 0.4 micron difference out in the wear bevel really fast...really really fast.
Spend the first $$ on strop material or 0.25 micron diamond powder ($15) or something like that and check the edge retention before spending $300 to find out that it's a difference in theory and on paper, but one that doesn't materialize in real world work because 1) it's marginal and 2) it's not the reason for the edge failure most of the time to begin with.
Not trying to be a jerk, just trying to save people some money on sharpening material when money is finite...and I say that as someone who has spent close to $4k on just stones of various types (hope my wife doesn't read this).
Guest
My only defense of a 1 micron stone (16k glass or 15k pro) is that it's pretty much immune to wire edges on A2, at least for practical purposes. Sharp is sharp with it, and not false sharp where you still have some wire edge hanging on that gets knocked off in work and makes an uneven edge.
The issue with finer grit and edge retention is that when an edge fails, it doesn't usually fail uniformly across the edge if it's not abused. If you can make the edge as uniform as possible to start with, you have a better chance of it wearing uniformly, too. A jagged edge always has unsupported bits of metal on it somewhere, and they are going to wear at different rates and get dull faster. It probably also has a better chance of losing impurities because they'll be presented in ways that they're not supported from all sides as well as they would be in a nice uniform edge.
Contributor
I have long thought of "sharp" being better defined as "smoother", that is, a smoother edge is a sharper edge.
One of the more common thoughts is that an edge with less serrations will also last longer. In other words, a smoother edge is a longer lasting edge.
Recently I have been working with a computer microscope and photographing the edges of different steels (at different cutting angles). This is still in its infancy for me, and I have to improve the resolution, but one thing I have noticed is that a worn blade is not smooth/rounded but serrated.
Here is a 200X resolution following 100 shavings ..
So back to the Shaptons. Smoother means a sharper and longer lasting edge. I do not have the 30K stone. I do use a 12K and finish on .5 micron green rouge or .5 micron Chromium Oxide micro abrasive on glass (both from LV).
Regards from Perth
Derek
Guest
Derek - it'd be interesting to find out how many shavings you had to get through a plane to make a 30k sharpened edge degrade to or past a 16k sharpened edge.
Your experience is similar to mine, though I'm not using as much magnification (but I have 20/8 vision, so I can see quite a bit at 30x or 75x). Edges that wear evenly feel sharper for a longer time, even if you can see that they've been abraded farther from the edge.
Check out the edge of a 25 degree bevel up chute plane iron under the microscope. At high magnification, it looks like the attached picture..
.. well, not quite, but sort of.
Member
I may be a mediocre woodworker, but I can put a mirror edge on a baseball bat. I keep opining on the subject of sharpening because I am so satisfied with my method, and there seems to be so many that are unsatisfied with theirs.
I use the straight razor approach to plane irons and chisels and serves me very well. I sharpen the tool to 8000, then strop on a rouged paddle strop, then strop on the leather. There may be 10 ways to sharpen, but as far as I'm concerned this is THE way to properly sharpen. Its unbelievable how much leather stropping makes a difference. You also prolong the life of the tool and the stones by whetting the edge often on the strop.
Anyone who shaves with a straight knows that. You can only get so far on the stones, but the leather lines those microscopic teeth up like nothing else. The hanging hair test just doesn't work with stones...its the stropping that makes it work.
Member
Can someone who is a big believe in the leather strop please describe their technique to me? I have tried stropping plane irons with the "green crayon" and have felt like I always make them LESS sharp. I have tried a leather belt on my belt grinder and that ruins a plane iron edge in short order (but works very well on kitchen knives). I have also tried pieces of leather free-hand and have also felt that it is not an improvement, but does not necessarily degrade the edge like the power stropping. I understand that the power stropping is probably not a good idea, but what is the proper hand technique?
(sorry for thread hijack)
Member
It looks like it has bugs on it.
Guest
Yeah, those are the super-rare chute board mites
Contributor
Check out the edge of a 25 degree bevel up chute plane iron under the microscope. At high magnification, it looks like the attached picture..
.. well, not quite, but sort of.
David, more so than you realise ..
Here are two recent images, both blades honed at 25 degrees and used for 100 strokes on a shooting board into hardwood endgrain.
What you need to know is that both blades still continued to plane endgrain quite well. At this stage they both did not feel like they needed attention (ordinarily, at this point, I would strop the blade).
Keep in mind that 200X magnification tends to exaggerate the serrations.
The first blade is A2 ...
Second blade is CPM 3V ...
Its unbelievable how much leather stropping makes a difference. You also prolong the life of the tool and the stones by whetting the edge often on the strop.
Exactly John. That's how I principally employ a strop - to maintain an edge, not create it.
Regards from Perth
Derek
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