Shapton Stones (how high can you go?)

[Pedro Reyes]

Hello all,

I have recently aquired some Shaptons (1000 & 4000 glasstones, 8000 Pro series). Long story why I have 2 glass and one Pro...for another day.

Before that, I used mostly scary sharp and most of my blades had a mirror finish, not just you can see yourself or you can read print, a finish that was no different than a mirror.

Now when I went for a touch up I realized that my 8000 actually hazes my previous mirror finish, I can still see myself and read print, but it looks hazy.

This may not matter but that is beside the point ;).

Do you guys (Shapton users) go higher than 8000 or is my stone dirty or am I doing somehting wrong?

any help appreciated.

/p

[Mike Henderson]

I can't give you any feedback on how shiny the 8000 stone makes an edge but it might be better to judge the stone by how well your edge cuts, rather than how shiny it is. If you find that your edge is not cutting as well as it did before, or the edge is not lasting as long, then you should start investigating. But as long as you're getting a good, long lasting edge, I wouldn't worry about how shiny it is.

You can always strop the edge with some honing compound to bring the shine up.

Mike

[Jim Koepke]

I was wondering about this my self.

Just now had an epiphany. You mentioned sand paper or scary sharp. When I was sharpening with a power set up, I would get a mirror with 9 micron paper. With the 8000 stone, it is a little hazy.

I think the sandpaper dulls as it is being used and does not have sharp edges to make the scratches resulting in a hazy look. The stone keeps presenting a fresh surface with new sharp edges to leave distinctive marks which appear as a hazy surface.

I am not sure, but thinking about the question, this made sense. Maybe someone else has a better idea.

It seems my edges are a little sharper off the stone than they are off the paper.

my 2¢,

jim

[Johnny Kleso]

The thing with grit is the faster it moves across the cutting edge the finer the finish..

But your talking with 9mic power and hand sharpening with a 8,000 (1.2 micron) water stone I would think they would be pretty close to the same finish..

You can check it out on my grit equivalencies page

http://home.comcast.net/~rexmill/sharpening/grit_sizes/Abrasive_grit_sizes.htm

[Pedder Petersen]

Hi Pedro,

on a german forum a member tested many stones and his statement is, that the shapton 8000 doesn't polish but leaves a sharp edge allthough. To understand that I had to understand that polished does not mean flat. Look at the new LV Blades they come as flat as can be but are not shiny at all.

Cheers
Pedder

[Pedro Reyes]

Thanks Johhny, So I used to go to 2000 wet/dry on granite (or glass). However I have seen other grit charts that place 2000 Si Carbide paper as less fine than an 8000 stone.

That aside, Mike I know that ultimately the way it works is what matters, but we could use shininess (sorry came up in a dictionary) as a measure of how fine the scratch pattern is, and we can also say that the finer it is, the better the edge. To me this qualitative (by eye after all) measurement is easier and faster to gauge than sharpness (also qualitative when we measure it based on how easy we shaved our arm or the miniscule difference in "feeling" when pushing a plane). Not trying to start any argument, mostly wondering if anyone has used 12000 or 16000 and achieved mirror off the stone.

/p

[Pedro Reyes]

Hi Pedro,

on a german forum a member tested many stones and his statement is, that the shapton 8000 doesn't polish but leaves a sharp edge allthough. To understand that I had to understand that polished does not mean flat. Look at the new LV Blades they come as flat as can be but are not shiny at all.

Cheers
Pedder

Pedder,

Thanks for chiming in (are our names equivalent? :)).

I think that with Johnny's help my question has been answered (in theory anyway). Sandpaper at 2000 is finer than an 8000 Shapton glass stone. Now just curious to see if anyone uses 16000.

Agree, polished (or shiny) does not mean flat, but it does mean that the scratches are smaller, which under magnification appear as peaks and valleys at the edge, and weaken it over time.

The reason I am being so stubborn is that shininess is easy to measure, the eye is an amazing tool, you would be amazed at how many different visible wavelenghts our eye can distinguish better than some measurement equipment.

/p

[Pedder Petersen]

Are our names equivalent?

[...]
Agree, polished (or shiny) does not mean flat, but it does mean that the scratches are smaller, which under magnification appear as peaks and valleys at the edge, and weaken it over time.


Hi Pedro,

there are many varations of Petrus (Simon) all over the world, two meets here. :)

Flat means sharp. Polished doesn't mean sharp and does'nt mean flat. I've got a set of two cherries chisels. They are polished but not sharp.

But I've to agree that the easiest method to control sharpness by eye is polishing. ;)

Cheers
Pedder (swedish form of Petrus with a mispelling by my father)

[Charles Shenk]

as a point of reference, my 8000 Norton waterstone leaves a polished mirror finish.

[Joel Goodman]

2nd that on the Norton 8000 -- irons and chisels seem pretty shiny to me after using it. I wonder if the weaker binder on the Norton -- just my supposition as I gather they get out of flat sooner -- means the grit somehow breaks down more easily than the Shapton and on an 8000 Norton after a while the grit in the slurry is finer. Can anyone with both stones compare them?

[David Keller NC]

I use the Norton 8000 (as well as the 1000, and 4000). The 8000 will leave a mirror if (and only if) I've been using it a while without flattening it, or I've been flattening it on 400 grit silicon carbide wet-dry paper. If I use the Norton "stone flattener stone", the surface returns to what it was when I bought the stone originally - it leaves a slightly hazy finish.

My interpretation is that the abrasive particles in the 8000 stone are getting broken down and packed into the pores, and the resulting surface is very, very smooth - chisles and plane irons stick to it by surface tension so that they can't be removed by pulling them directly off of the stone. After using the stone flattener under running water, the surface is slightly porous by feel - I get the impression that the stone flattener and the running water is removing all of the swarf from the re-surfacing.

Point here is that I'd expect the Shapton to behave similarly - if you flatten it on a surface plate, piece of glass, mdf, etc... with a piece of SiC paper where the resulting slurry isn't flushed away and is in direct contact with the stone, I'd suspect you'll "convert" it into a much finer abrasive surface, though one that's slower cutting.

[Wilbur Pan]

I've found that the 8000 grit Shapton leaves less of a shiny mirror finish than the 5000 grit Shapton, although the edge definitely is sharper. What I see is a bit of a "oily" sheen to the bevel, sort of like when I go too long before cleaning the inside of my windshield.

Another data point to suggest that mirror finish does not necessarily equal sharpness: my natural Japanese waterstones leave an edge that is at least as sharp if not sharper than the 8000 grit Shapton. However, it leaves a fairly hazy appearance to the bevel -- almost like a semi-matte finish. This is nice for Japanese tools, as it makes the lamination between the hard and soft layers really stand out. With the Shapton, the bevel becomes so shiny that you can barely see the lamination lines.

[Zahid Naqvi]

I guess the real test in terms of sharpness is the tried and trusted "shaving the hair off the hand test". So if you can do that with the Shapton 8000 shine, or lack of it, really doesn't really mean anything. I only go as high as the 4000 followed by a strop.
So can you shave the hair after finishing with the 8000.

[Will Blick]

Great thread, some comments....

Polished means the small grooves are lessened. The smaller the grooves, the clearer the reflectivity....to the point, the metal resembles a mirror (1/4 micron paste) The more reflective the surface, the smaller the grooves are, caused by the abrasives. However, as mentioned previously, a SHARP edge is a combination of a polished surface (to a given level) and two FLAT surfaces which is mandatory to form a SHARP edge. But surfaces must be flat and preferably honed to the same grit. (which is why a flat abrasive is ultra critical)

If you want a shiny DULL edge, often improper stropping and buffing wheels will do a good job at this .... so beware... we all learn this the hard way.

How shiny the metal becomes, is often a function of the metal type, in addition to what girt level the surface was honed.

I agree with the "shave the arm test".... human hair is a tough test for a thick blade.... the flexibility of human hair, due to high protein content will resist cutting when not held by another metal member, such as scissors. I have found, any blade that cuts your forearm hair with ease (there is different degrees of "ease" of cuts) is a joy to use for cutting wood.

As for stone grits. I used to think 8000 stones produced a sharp edge....and by most peoples standards, they do. But some of us suffer from OCD when it comes to sharpening. So next, I went to the Shapton 15k stone, and it is superb, a significant sharpness jump (the Pro, not the ceramic). Then, I went to Shapton 30k ceramic stones, and while it will produce true mirror reflections, the added sharpness is not equal to the 8k to 15k jump.... but still slightly noticeable.

Then, I bought some 1/4 micron diamond paste.... this was a step up from the 30k stone, probably more trouble than its worth, as you always need a clean surface and the swarf waste becomes the limiting factor in how long an area can be used, hence the beauty of the water stones. One big improvement I adapted is keeping a constant trickle of water over the stones while in use, this continuously removes the swarf, so your edge is only contacting the "right sized" abrasive material..... with out this, your edge is limited by the size of the swarf waste particles, which are also capable of scratching the edge, so we should consider the swarf an undesirable abrasive, as its size is not controlled.

Another interesting finding, and sometimes documented...is which stone types work best with a given metal alloy. I have not done enough research in this area, but its well known that certain metal alloys should be married with stone types..... it seems the ceramics are most sensitive in this area....however, ceramics, from what I have gathered, is generally acceptable with wood working metals, mainly A2 and O1.

Also, one of the best lessons learned about plane blades is on a web site by Brent Beach.

http://www3.telus.net/BrentBeach/

Brent discusses the need to put a bevel on the flat side of a plane blade. IMO, this is a critical component of creating an equally sharp edge after re honing. He mentions how a new blade, honed to a certain grit will be ultra sharp....but after re-honing, the blade will only be "sharp" vs. ultra sharp, meaning a fall-off in sharpness. Same technique, yet, the blade is not as sharp? This is a result of, the front edges micro nicks were not removed, as the edge was not pushed back far enough to rid the micro nicks. The secondary bevel (approx. 3 degrees) on the flat side allows you to push back the edge far enough to remove the nicks, in less time, as you are removing much less material. This refers mostly to BU blades, and i think Derek Cohen has addressed the application of this for BD blades.

I plan to start implementing this into my sharpening protocol...another project....

[Pedro Reyes]

Will,

Thanks, very useful information. I'm glad you posted this because I didn't want to start an argument about how polished surfaces do in fact mean that an edge is sharper provided the two surfaces intersect at a line with close to zero raius, BTW these surfaces could be far from flat (imagine a curved gouge).

Very useful post, both from theory and empirical perspectives.

/p

[Will Blick]

Pedro...yep.... flat surfaces IMO is the hardest to control, specially on micro bevels. The two critical factors as I see it are.... a FLAT stone (which requires constant maint. to keep it flat) and a consistent bevel-to-stone angle. IMO, this is the beauty of the honing guides vs. free hand. I have seen some good free hand honers, but its so easy to be "slightly" off, and never know it. Part of the problem is, none of this is visible...
I do use a nice 100x magnifier, and it is helpful, but only shows tiny areas, so you can never see the full edge to monitor your true progress.

[Greg Muller]

I understood the 'flat side bevel' explanation and actually believe the argument, however I think the same effect can be had without creating a noticeable (to the eye) flat-side bevel. I usually run the flat side across a strop a few passes before my final 5 or 6 strokes on the actual bevel.

Greg