ESCHER Lapping and Slurry - QUESTIONS

Gents.....I recently acquired a decent sized Escher stone off eBay. This is my first Escher and I’m quite satisfied with the size and condition. It measures about 8” x 2.75” x1.10”. It looks liked someone tried to do a little breadknifing on it and it doesn’t look like it’s been lapped in a couple of decades, so it is going to require a bit of lapping. I’m planning to start with sandpaper and will finish on a 300 DMT. What size grit should I start with and how high should I go before I hit it with the DMT? Other than washing part of the stone down the sink, is there any advantage or disadvantage in lapping both the top and the bottom? (The Escher label is on the lid of its wooden box.)

Once the Escher is properly lapped, what should I use as a slurry stone? I hate the idea of cutting of an inch off the end, even though it’s probably long enough to do so. I have a couple of Coticule bouts. What about using one of them as a slurry stone?

Thanks in advance for your help and suggestions.

Freehand

I use my DMT 325 for just about every stone/hone to raise a slurry including my Escher... Unless you just want to do the extra work I can think of no reason to lap both top and bottom, many do lap one side of a hone for a thin hone if needed ....

Lapping for flatness I tend to start with the DMT 120 then the DMT 325 and done,,, many stones are close enough that I only use the DMT 325...

The grit of the sandpaper (only use wet/dry) can be pretty much whatever you have. Eschers lap fairly easily, but you can start around 180 or so. If you are going to finish on a DMT 325, then I wouldn't use any sandpaper more coarse than that.

I would not use a coticule to create slurry on an Escher. You'd just be mixing the two slurries. If you already have the DMT 325, that will work fine for creating slurry.

I have been jumped on for this in the past, but I'm cheap and waste averse, so here is another option...

When you lap your hone, do it in a bucket or deep pan so that you can retain and collect the slurry water. Store this in jars and dilute or concentrate it as you see fit. When you want slurry, shake up the jar, draw up a little bit of the slurry with a syringe (or whatever) and transfer it to your hone. This way you don't waste the lapping slurry, nor do you wear out your hone as fast creating additional slurry each time you need it.

Sounds like a great piece of rock:)

I would just lap one side. No need for two sides, and thus reducing size of it.
I lapped my Escher with a DMT 325, that worked out ok. Didn't take long at all.
For slurry on it, I use a Tomo-Nagura (Oozuku or Shoubudani).
They are much harder, and the released grit is all from the Escher.
In a pinch, I guess a DMT 1200 would do the trick as well.

I must say though, I hardly ever use slurry on it anymore.
My stone works wonders without it, solely as a finisher.

I agree with all of the above, but unless you hone professionally, you could lap all 6 sides flat and still have a few lifetimes of stone left.

Echoing the others. The DMT 325 should be sufficient for lapping and also raising slurry. Eschers are quite soft and lapping them only takes about 5 minutes.

I lapped mine on 1k sandpaper, took less than five minutes. I don't know what you have in mind for your stone, but I'd try it out purely as a finisher before playing with slurry. I presume you have a coticule and, IME following that with an Escher can be quite nice (YMMV etc).

The escher is so soft that I've been using the slurry stone for Chinese finishing hone. I'm not really worried about grit contamination because the Chinese is much much harder than the escher.

I would use a Chinese 12k slurry stone, if I had nothing else. Do not use a Coticule Slurry stone on an Escher.
Escher/Thuringian slurry stones can be had on the net still. I bought a few a while back, and I'm very satisfied with the results.