Thread: Getting a Natural Flat

There are many threads on this but I wanted to share my own experiences and seek the wisdom of the Tribe of the Stone.
I just lapped my Nakayama asagi on 1200grit and 2500 grit wet/dry on a glass window pane in my apartment which pivots to lay horizontally. I've done this before, starting at a lower and finishing on a higher grit, but today I tried something new.
After a few pencil grid checks on the 1200 paper I had a nice puddle of mud on the glass window so, reflecting on the three stone lapping trick Jim and Hide have shared from their visits with masters of the craft, I lapped my stone on the mud puddle. Essentially, my stone lapped itself.
Just to be sure I drew pencil lines again and lapped on the 2500 grit, the lines disappeared very quickly with no pressure, so I removed the paper again and lapped on the remaining mud. The surface isn't as refined as it will be with repeated honings and nagura conditionings,but it is noticeably smoother than the sandpaper alone would leave, with no scratches.
All that said, I did leave scratches and a slight haze on the glass. I wonder if the landlord will notice. This brings into question the idea of using grits on glass or granite over time, but with what I have available this more than suffices for now.
I was even able to do that gliding spinning hone trick I've seen in videos, which seem to prove the stones are lapped as flat as can be.

Haha, using hte apartment window. brilliant

I've heard of people using lapping grits before. Also, with lapping plates that don't strip (like the Norton or Naniwa plates), you can do the same thing by letting the grit from the hone you are lapping build up.

Definitely a good idea.

I'm curious about this stuff. Clearly you guys are using the nagura-type honing on a hard, high grit finisher. And equally clearly, this approach dishes the finisher so that you need to lap it, is that right? Or is this simply that people don't like nagura scratches on the surface of the finisher and so lap it more often?

James.

This was me correcting dishing caused by what I believe to be improper nagura use, over confident kamisori honing and just being new to how to treat a stone. Now that I've hit a certain stride with this set up and getting consistent results and information from the stone, I'm hitting the reset button on my past mistakes.
With proper use, I shan't need to lap too many more times. And as I improve my handling of the nagura the surface will get better with time, something I've noticed especially when using just water.

Go to a big box store and buy a square tile of granite or some other rock. They come in like 12 inch or larger squares. Even if you move it is a great thing to have around. I use it now for my bench planes.

Later,
Richard

Originally Posted by Jimbo

I'm curious about this stuff. Clearly you guys are using the nagura-type honing on a hard, high grit finisher. And equally clearly, this approach dishes the finisher so that you need to lap it, is that right? Or is this simply that people don't like nagura scratches on the surface of the finisher and so lap it more often?

James.

I haven't "lapped" my stones since their first use, so I wouldn't say this method causes significant dishing.

I remember ZethLent mentioned a mesh abrasive which worked well, but the meshes I've seen in local hardware stores are drywall and very low grit. And I'm lazy in NYC but the tile idea is a great idea.
Jim: I... Totally forgot what I was going to ask you.
Oh. Have you tried the three stone round robin flattening trick? And, if a beginner (like me) brought you a stone with mild dishing and minor scratches, how would you flatten it for them?

I probably couldn't answer, anyway.

Originally Posted by bassguy

And, if a beginner (like me) brought you a stone with mild dishing and minor scratches, how would you flatten it for them?

I'd use a worn off dmt 325, coticule, Jnat prepolisher and it is all set to go.