Re: Water Stones
Schtoo
Hi Roger,
Normally I would take this to email, mainly because I am intensely unwilling to show any bias that may make you sway your purchase. That's because yes, I do sell stones, namely Sigma Power (ceramic and Select II) Shapton (Pro, Glass and M5), Naniwa (Chosera and Superstones) Bester/Imanishi (many different stones, none labelled as 'Imanishi' so not the same as LV) King (Deluxe, Neo and soon Hyper) and soon, a few 'off brand' stones that have merits, but are a bit of a dead end if you're looking for a 'set' of stones. Good stuff, but mostly out there on their lonesome.
What Joel mentioned about the FWW article is true. The article does have flaws, but against all odds, the end results were surprisingly accurate with regard to the results that were required. Really very interesting how ugly it started looking, but how well it turned out.
To your original question.
A2 isn't much of an issue for most of the current crop of waterstones out there. The King Deluxe are struggling (and their design is 50 years old or so now), Superstones will struggle with a full bevel, but nearly everything else really doesn't care that the edge is A2. They're designed to cope with at least blue steel, which is probably no tougher than A2, but blue is usually significantly harder and poses more of a problem for a stone.
What you'll want to be considering now is which stones are going to get your blades sharp with the least fuss, trouble and the fastest. Cost can also be an issue for some, but I try to avoid much mention of that.
The points to consider are speed, dish resistance, ease of use (soaking, flattening, general care, etc.) and the resulting surface/edge on the blade.
In general terms, here's how they all stack up. (some of you may wish to save this. I don't write it very often, and never in public.)
Bester tend to be quite good. They stay flat and work fairly well. I find issue with my #1000 to be too hard, my #700 and #1200 to be too soft by comparison. I can manage that, but not everyone can. The higher grit stones are quite good, but my experience is very limited and I can't say they're 'that good' that I feel the need to pursue them for sale.
Chosera are excellent. They work VERY well, all the time. They do dish a little more than some, but they are very easy to use and work very quickly giving good surface finish/edge. Only quibbles are they're not that nice to flatten (sticky mud) and they can be somewhat fragile and problematic to soak at times. Small concerns, but still they exist.
Superstones can be summed up in one phrase. "They grind slowly, but exceedingly fine..." Grit for grit, it's nearly impossible to get a nicer finish off a stone than the SS gives. But, nearly every stone commercially available works faster. If you can stick to very narrow bevels, no problem. I find they tend to stay reasonably flat and work ok. Not my favourite stone, but if you work within their limits, they're nice and quite user friendly (no soaking, some feedback).
Shapton Pro are very good. The 1000 stays flatter than anything else out there. Needs no soaking, works fast and is easy to use. It's the star of the lineup IMHO. A lot of folks love the 1500 and 2000 as well, which I can agree with. The problem is that the other stones in the lineup are good, but not great. The #5000 can be a right PITA at times, needing a very gentle touch (unless you soak it, giving it some flexibility, literally), the #12000/15000 is nice enough (and nicer if soaked), but IMHO outclassed by a few stones in the outright edge it gives. Overall, not bad but not perfect by any stretch of the imagination.
Shapton Glass are odd. The low grit stones are really very good. But once you go beyond 1000, things start coming off the rails. They get progressively more recalcitrant to use, and while they can give very good results (better than the Pro ultimately), the envelope of operation is very small. If the Chosera are like an open roller door, the Shapton Pro are like a small, open window and the Glass are like a mail slit. They are compact however, tough and for travel, unbeatable. You just have to learn how to use them, and I, for one, am unwilling to bend to their idiosyncrasies because I have better options available to me. And no soak, but also very thin (and the stuff doesn't last!).
Sigma Power ceramic are very good. Second in dish resistance to the Shapton Pro at 1000 (places reversed at 5000-6000), easy to take care of and easy to use. The Chosera feel nicer, the Shapton Pro stay flatter, the Superstones give a better finish, etc, etc. At almost every point I can give you a stone that will do something better than the Sigma ceramic. The reason why I like and use these stones is that I can usually only pick a single stone that does something better, but in another area, the 'better' stone is something different. Rarely/never "the best" at anything, but usually second or third best at everything.
Sigma Power Select II, maximum overkill. In FWW testing they did 'poorly', but the testing was geared more toward the conventional stones, and did no favours for these things. Used correctly, the fastest stones available. Not so easy to use, since they do dish rather quickly and it's difficult to compare them to anything else because they're unlike anything else out there. If you want to consider these, google the heck out of them and communicate with folks who've got them and use them. Folks who have them usually fall in love with them, but they've also learned to 'tame them' somewhat as well.
You must also take into account what you'll be sharpening (in this case, A2) and how you'll be sharpening it. If sticking to microbevels and ruler-tricked backs, then all of the above are quite user friendly and will work very, very quickly. If more than a postage stamp worth of steel, that's where the stones mentioned as being 'not so user friendly' start causing some concern.
In short, there are so many variables and so many options out there it's becoming increasingly difficult to make a choice. A lot of the time the difference between one stone and another is only measurable under strict testing conditions. In the real world, it's nearly impossible to tell what stone did what if they're at all close in performance.
I think that the outright performance of a stone will become less of an issue in future, and more a case of "how nice is this stone to use?" It's already starting with a lot of people considering oilstones with their low maintenance, easy use and still good performance.
A lot of folks will not give up their waterstones though. But they will be looking more at 'how they work' more than the speed and outright edge, especially with more choice out there meaning you don't need to give up one desirable trait to gain another.
None of these stones should really be flattened with sandpaper. You can ignore that, and likely never have a problem. However, I've been specifically told by reps from Naniwa and Shapton to not use 'sandpaper' with the above stones, Sigma Power says "not a good idea". Bester, I don't know what they say. Softer stones like King Deluxe and Norton, it's an approved method so go right ahead.
I've been trying to work out why sandpaper isn't a good idea, since I was told that 'contamination' was the problem, and I don't think I understood correctly from what I was told (in Japanese of course) or those informing me may have been somewhat in the dark too and simply following the company line.
I think I've workout out why it's a problem, it's not what I originally thought was the problem, but the result is the same.
On softer stones, the sandpaper holds up well. Anything dislodged won't be stuck fast into the stone. On harder, denser stones, more particles can be dislodged from the paper, and with more of them rolling around, chances that some will embed in the stone is much higher. Because the paper is 'soft', it can more readily catch and lodge the particle into the stone. Loose grit on a hard surface tends to roll more easily, and particles don't lodge into the stone. Diamond plates hold their abrasive more solidly, so nothing other than stone material is present, and there's no harm.
I'll try and find out exactly what causes the concern, but really diamond plates are easier, loose grit is ultimately cheaper. I've never used sandpaper for stone flattening, and never will. The thing is, flattening should be done just before sharpening with the stone wetted down. Loose grit and diamond plates don't care about water, sandpaper (even W&D) does care about water and may give problems. I don't know what sanding screen will do, so I'll check that out too.
(But I know folks who'd be horrified about flattening a 10K stone with something so coarse!)
There's no reason you can't use steel on the diamond plate directly. The things to keep in mind are that you must let the diamonds do the work, which means little or no pressure. On a good stone, you can really lean into it which can make the work go faster. For flattening backs, diamond plates are good. Also know that working steel and flattening stones wear diamond plates differently, and combining the two tends to make the plate wear out a lot faster. It won't fall to pieces immediately, but the wear is pronounced significantly. You might also notice that the plate actually works faster with steel since the stone cleans the plate (which is partly why they wear faster). I've used diamond plates in both capacities, and will do so in the future but I tend to lean toward stones because A: I've got them and B: I prefer the feedback and ease of use a stone gives.
Also know that a diamond plate essentially gives you what it says on the box. If it says "10 micron/#1200 mesh/whatever!" that's what you get. The surface it leaves will be clean, but full of very sharp valleys, at least until the plate has significant wear on it (and at which point it's slowed right down). The next sharpening device should flatten out the peaks to the level of the valleys to the best of it's ability. A stone will leave more rounded valleys (but still rather sharply v-eed) and will also push metal around more than a diamond plate will. The simple version is that a diamond will sharpen your tools, but in a different way to a stone. There's a case for stones doing a better job, especially when taken beyond the #5000/2 micron level. Fewer sharp valleys, smoother edge. I've talked with some folks here about this, and the general consensus is that diamonds are ok in some cases, but none of them will use them for the final edge on anything but HSS and carbide. I tend to agree, and hopefully can do some testing to find out if there's any truth to this at all.
I don't know everything and I don't do as much sharpening as I really should. I don't have enough experience with every sharpening method available, but I also won't sell something for sharpening (at least) unless I've tested it thoroughly and decide it has something to offer that's worth the price demanded.
But, I hope the above helps. I hope it's not too biased in any direction, and the above are my genuine thoughts on the matter. Copy it down, but don't make it gospel, it's always subject to change.
(Especially when folks who make the stones send you samples to test. Apparently there's something new coming that might make some of the above null and void. But I don't know yet!)
Stu.
(I don't know why I wrote all that out. It's going to get attacked, manipulated and probably come back to haunt me. Merry Christmas...)