From: ken watson (watsok@frii.com)
Date: 09/24/01-06:11:37 PM Z
The only UV clear "glass" is made from quartz vs silica. The green color is
Iron in the glass. It is possible to get Iron free glass that in either not
green or much lighter green as seen from the edge.
As for quartz glass ???? in large sizes
..-----Original Message-----
..From: Richard Knoppow [mailto:dickburk@ix.netcom.com]
..Sent: Monday, September 24, 2001 5:55 PM
..To: alt-photo-process-l@skyway.usask.ca
..Subject: UV Transparent Glass
..
..
.. Some time ago I aquired a Morse contact printer. This thing was made for
..printing from aerial survey negatives and has 39 little Argon UV lamps in
..it. Not intense enough for alt use, but useful for slow silver paper.
.. I got it cheap because the glass top had been dropped. I had a new top
..made from plate glass but its green and seems to have substantial blocking
..of UV (judging from the diming of the fluorescence of the brighteners in
..plain paper).
.. I was told that clear glass was available only on special order and was
..very expensive.
.. It seems to me that the UV transmission of glass is of interest to alt
..people. So, I am wondering what knowledge might exist on the list about
..kinds of glass available for, say, printing frames, which has better UV
..transmission than ordinary window or plate glass.
.. The current thread on making a printing frame made me think of this.
..----
..Richard Knoppow
..Los Angeles, CA, USA
..dickburk@ix.netcom.com
..
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