Question on flattening ceramic water stones

[Tony Wilkins]

I have one question (simple I hope) as I consider moving from King water stones to 'dish resistant' ceramic water stones (e.g. shapton, sigma). I'm used to flattening my stones at least once during a sharpening session (usually at the beginning or end).

With 'dish resistant' ceramic water stones (say Sigma for instance), how often do you flatten the stones?

[David Wong]

I have and use all the stone brands you mentioned. I tend to flatten all the stones more or less the same. Perhaps flattening the shaptons and the sigma 400 a little less frequently. I sharpen by hand, attempting to even out stone wear, but will lightly flatten frequently.

[Malcolm Schweizer]

I have noticed that the Shaptons do not dish as fast as the Nortons. I still flatten them each major use but just don't have to do as much each time to flatten them. If I just use them to touch up a blade I don't bother with the flattening ritual.

[Frederick Skelly]

I flatten my shapton after every use. It doesnt dish much, but doing so also seems to refresh the cutting surface. I just run it over some wet 400grit paper on a very flat surface until its fully white again.
Fred

[Stuart Tierney]

Depends on what you're doing.

Normally I put away my stones rinsed off, but dirty. Wet and flatten before use IF they've had a hard time the last use, or if not, I leave them be. Mess and all, saves me generating that messy stuff again.

Let me explain a little further, but still quickly.

Recently I've had to prepare a handful of plane blades from factory grind to fully sharpened, ready to use.

I started with a #400, splashed with water and given the once over with the diamond plate, but the leavings of flattening left on the stone. A little more water and a rudimentary back flattening. Not completed, just started. These are not my blades, and I don't flatten backs any more. If it were my blade, I'd catch up on the flattening over multiple sharpenings. I'll go down one side, then the other until the stone stops cutting rapidly and/or gets heavily loaded. If the blade needs more work, I'll rinse off the loading and keep at it a little further. This particular #400 that I use tends to stay very flat, so no need to flatten.

Then, the blade goes into a generic honing guide, and I'll adjust the blade so I'm working the entire bevel and raise a burr along the entire edge, detectable with a fingernail (or plastic pen barrel, etc.).

Next, the #1000 hard (as these blades are laminated, and the hard is the best stone for these blades), I'll splash some water on, rub the diamond plate over it to check for flat AFTER it's wetted, then get to work on the bevel, adding water as needed. I've told lots of folks to soak this particular stone, but I'm not following my own advice...

(Splash and go seems to be hip and cool. So I must be hip and cool too!)

Once the burr is reduced in severity, I'll get down the #6000, and work the bevel until the burr is reduced again (but still present, just) and most of the scratches are gone. Note the splash not soak in the previous step? As the #1000 finishes it's job, it tends to refine the edge a little as well, making for less work for the next stone, the #6000 in this case.

Next, #13000. The 6K and 13K might get flattened after several blades, but really when the stone is covered in 'black' and I think it needs a flattening. Also note I do not use the entire surface of the stone when I sharpen with 6K and 13K, just a small area at a time. Again, as the stones load, they get a little finer in their action. Also, no soaking, just a splash of water so the entire surface is damp (the areas I'm not using supply water to the area I am using), not wet.

(At the moment, the 6K and 13K are in one stone. I rinse off the honing guide when I flip the stone over, but don't worry about contamination. Anything that ends up on the 13K side is pre-worn 6K, made of the same stuff as the 13K and won't cause more than a second or two of extra work. That doesn't mean than cross contamination is a 'nothing' thing, just that it's not a concern with this particular stone.)

Once the burr is effectively erased, I'll take the blade out of the honing guide, and work the back. I'll not use the diamond plate on any of the stones from this point on, and don't even flatten them before working the back. The #1000 works what the #400 did, the #6000 and #13000 are used with a ruler to create a small back bevel (ruler trick) and get the edge sharp. Once I've got an even finish from the 13K on the back, I'll work the very tip of the bevel on the 13K and then the back one more time. Very small amount of work, just to erase any sign of burr. Then a strop on my palm or jeans, a wipe down with oil and a dip in plasti-dip, let that dry then blades back into their packages and out the door.

The process for a new blade of this type takes about 5-10 minutes. The next batch through should be better, and the 40mm wide blades I've prepped take 2-3 minutes maximum. It doesn't take long, but that also comes from knowing what I can and can't get away with from the stones. It also comes from not being afraid to push blades into the stones, not afraid to run the sides of the blades way off the edge of the stones, I don't count anything and work until the job is done, no more, no less. In short, almost everything that has been said to be 'verboten' at one time or another, I actually do.

Mess is limited to a little black slurry on the tray I use and what's on the stones that gets washed off before they're put away. Or not, depending on how much mess there actually is. Very rarely, I know a stone needs some attention and I will flatten it while it's still damp/wet.

If it's one of my own blades, the process is much faster as I don't use a guide every time, and my blades are already in good shape for sharpening. I might get a few to a few dozen sharpenings between flattenings/cleanings, but at the same time I don't flatten religiously, nor do I skip it when it's needed.

Sounds complicated perhaps, and I know someone will come in here and tell you their stones/methods don't take so long, don't need so much effort, etc, etc.

I don't have time to play with stuff that isn't effective and fast, especially not at the moment. And I don't have time to 'hand hold' stuff that needs special attention and whatnot. I need stuff that is predictable, reliable and efficient. I don't care who made it, I don't care where it comes from, just so long as it works.

Stu.

[David Weaver]

I generally refresh those stones that there are fresh particles before I would ever need to refresh them due to flatness. If the sP 13k is soaked, it's been my experience that it will not load because it sheds just a little.