Well its not a LI for sure then!
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See: "Pierre a aiguiser naturelle des Pyrénées" on You Tube
https://www.youtube.com/watch?v=aw5fkyzYmr8
The have engines to flatten the stone!
Impressive.
--james
You could find a shop that has a Blanchard grinder with diamond bits or use a gem grinding rotary table. This would flatten your stone to the point where a subsequent simple hand lapping would give you the final finish you need.
Jerry
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P.S. You might also have luck with a belt sander to lap your stone.
Attachment 118823
This is the baby. Not as hard as I thought it might be, so can be lapped as normal. Not sure how fine it is yet.
In the video; Pierre a aiguiser naturelle des Pyrénées - YouTube
What is he putting on the stone at 7:15?
The paste is Colcothar mixed with sheepfat. Colcothar can be used as a paint pigment as well as for grinding and polishing. Contrary to what the name suggests, colcathar is non-toxic.
Colcothar is a red and purple dye, almost entirely consisting of iron oxide (Fe2O3) and clay soil. It is an artificial mineral pigment. It is extracted from weathered iron ore rock or clay by a process of washing and grinding.
Colcothar contains about 87% iron oxide and only 10% English Red. These pigments have been used since the ice age.
See page 41 Grinding and Honing: http://bosq.home.xs4all.nl/info%2020...ing_part_1.pdf
Colcothar mixed with sheepfat sounds like the red rouge we use for polishing jewellery.
I know "red rouge" sounds strange to anyone knowing a bit of french but they come in lots of colors and are all called "rouge", by tradition I guess!
I'm afraid to look at your papers Margeja, everytime I get stuck in them for hours...