Thread: Ozuku Jnat lapping with DMT 325?

The thing to remember with DMT's is that they don't recommend using anything finer than the 325 for flattening. In fact they recommend the extra extra coarse for hard Arkansas stones. The 1200 DMT can be easily turned into plain steel bar with excess use on hard stones.
On the other hand the 1200 Atoma plate works great as a slurry stone & light lapper. I have personally seen a 1200 Atoma which is still in use after approx 10 years.

alx!

How good do Atoma plates hold up with time? I would suspect you use yours regularly, how long does it take to totally wear out one? I have an Atoma 400 on the way for flattening, and heavy bevel work on problem razors.

So Yamashita told me that he only uses his Atoma (600 or 1000) for lapping and generating slurry.
And the thing with such stones is that they are finishers.
In other words, if you spend all that time lapping it, and then 20 minutes rubbing it with other stones, you're spending a whole lot of time just wasting time for no purpose at all.

Scratch lines in a hone do not matter, so that's not an issue, and if you just use it as a finisher, it will stay more or less flat and only needs a couple of laps to stay flat. Everything you do more, you're just wasting precious stone and precious time.

Originally Posted by jeness

alx!

How good do Atoma plates hold up with time? I would suspect you use yours regularly, how long does it take to totally wear out one? I have an Atoma 400 on the way for flattening, and heavy bevel work on problem razors.

If not abused and under normal everyday useage they will hold up for years and years, but they do wear down over time through attrition and the cutting action mellows out somewhat. The diamonds are mechanically fixed onto the plate by a heavy deposit of electroplated nickel which surrounds the diamonds like a bezel as they lay flat on the plate in the electrolytic bath. The plates are designed to grind flat items flatter and the diamonds take the brunt of the labor when used like this. It is when you try to grind a 3 dimensional items like I did with an axe head, this is when the nickel base can be compromised and you can end up with a bald spot on the plate devoid of diamonds. I still use the baldy plate for somethings.


Beyond exotic alloys like tungsten carbide there are no harder simple carbon steels used in edge tools then those of the Japanese and I wore out the center area an Atoma reshaping the face of an old japanese axe. It was the corner angle grinding work that ate up by undercutting the nickel base of the plate. But for flattening stones which are already generally flat or even for beveling the edges of a stone the Atoma hold up as well or better than most. I think it comes down to the thickness and quality of the nickel deposit holding the diamonds in place. Alx

For those that don't know the Atoma surface is very different to the DMT. Atoma pic below:
It's kinda raspy for want of a better word. I don't like the 400 Atoma on razors even badly damaged ones but it laps Shaptons pretty quick.