From: James Young (jamiehy@globaldialog.com)
Date: 07/16/01-11:38:13 AM Z
>I'm sure a chemical etch would work, but here's what I did:
>
>I got two pieces of glass (just ordinary window glass) of the size
>that I needed, put some automotive valve grinding compound between
>them and started grinding them together in a somewhat circular
>pattern. After doing this for a few minutes, I washed off the
>grinding compound, dried the glass and looked to see how uniform the
>grinding was. I then put more grinding compound on and put pressure
>on the areas that were still shiny.
>
>The first time I tried this, it took about a half hour to get a good
>5x7 ground glass. Later, I made a 4x5 in less than 10 minutes.
>The finish is a bit more coarse than modern camera glass, but that
>could be improved by using a finer grade of grinding compound, like
>the compound sold for making telescope mirrors. (600 grit, or so,
>in US terms. I think the 600 refers to the number of grains of
>compound per inch, so its probably called something different in the
>rest of the world) I used the valve grinding compound because it
>was easy to buy.
>
>Of course, be careful handling the glass since the edges are sharp.
>
>Bill
A good source for grinding grit is the local rock shop. Most rock
hops sell grit for polishing stones.
I just got some 600 grit material for about $4.00 -Way more than I need.
Jamie Young
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