Perhaps I have been a bit naive about buying things, but I sort of assumed that new sharpening stones would come in pretty flat. Imagine my surprise when basically every Arkansas stone I've gotten has been wavy or fat in the center. Sure, I get that we're not buying reference standards, but still... Not even close.

I suppose it is sort of like chisels and planes, flattening sharpening stones may be another one of those rites of passage, but I need another hobby like I need a hole in the head.

Is there any way to flatten oil stones that doesn't involve spending yet another pile of money and hours and hours of time? Maybe it's just the ones I bought, but still....

I sure hope it gets easier once they're flattened that first time.

So... I started going through my Arkansas stones, and so far, I'm o-fer on them showing up flat. (Granted, I have a Dan's on the way, and I hear they're good.).

The Norton soft had a smile. Concave on one side and convex on the other.
Both Natural Whetstone softs came in weird and wavy and low on opposite corners. (one was sold as a hard... but it was softer than the soft.).
The Smiths was wavy and low in the corners.
The Norton Hard translucent is thin on the ends and fat in the middle.

The Smiths was the smallest, and also the easiest to flatten, as in objectively easy. I was done in less than 20-minutes. I didn't measure the density (it's glued onto a plastic base) but I would guess low.

The Norton soft was the next easiest, but easy here is relative. I probably burned 3-hours on it. It is also the lowest density Ark I've measured so far at 1.97. Still, it's almost 0.030" thinner than when I got it.

The NW soft stones are where the problems kicked in. They're both wavy and fat in the middle. I've probably got 5-hours in them experimenting with methods, and I've only got one side of one pretty flat to the last half-inch of the corners (low), but all the other sides are still sort of wavy.

The Norton Hard/translucent... I think I'm going to punt on this one and send it out to get it lapped. Yikes, it's both really hard and fat in the middle on both sides. It would probably be ok if it wasn't that far out, but it's almost 0.030" thicker in the middle.

If this is typical of the breed, it's got to be one of the reasons people esteem water stones so highly. A hard stone, like an Arkansas, coming in out of whack makes sharpening take even longer.