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Hi All,
This is the first time I'm posting message to the list. And first of all I
would like to greet all of you. It's really so great when people share their
hardly won experience following the real ATM spirit.
In 1991 I was to pause my ATM practice due to specific economic and
social conditions (poverty and total disorder) in my country and collapse of
Soviet Union. I'm russian and I live in Tashkent/ Uzbekistan but
still I call this country Russia mostly because of my mind's inertia.
Nowadays things are going beter, so good that I decided to go on
with telescope making. The first surprise is that there are
no abrasive vendors left on the local market. Briefly speaking I can
not find even a simplest emery.
I have experimented with the ordinary sand and found out that this kind of
material is absolutely insufficiend for glass grinding. It breaks down after a
couple of strokes and seems to do very poor work on a glass. My
next idea is to use silica. As I remember from the university
mineralogy course - silica is 1.4 times softer than emery, and 2 times
softer than aluminium oxide. The difference is not too big. I found
out that the grit used in metalurgy for sand blasting and moulding is almost
pure silica. Now I'm almost sure that it will work but before I try
I'd be happy if anyone will confirm or deny this idea.
The same story with polishing materials. I can not find either cerium
oxide or the red powder (sorry I dont know what is it in
English). The idea is to use green chromium dioxide(Cr2O3).
This stuff is used for polishing metals. I don't have a fine grinded glass to
try it but I polished a 100 years old copper kettle - the result is very
impressive. All comments are wellcomed.
By the way sorry if I'm rising theme which is chewed and swallowed many
times ago, but I haven't found anything on the subject in russian ATM
literature.
Best wishes, Merry Christmas to all.
Dennis Nikitin,
Tashkent/Uzbekistan.
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