Re:Help with printing frame glass
j.r.anderson (j.r.anderson@mds.qmw.ac.uk)
Tue, 01 Apr 1997 09:16:44 +0100
>I recently purchased a used vacuum frame which unfortunately has a
>small hairline crack in the right hand corner. For now it seems to be
>usable, but I suspect that at some point in the future I will have to
>replace the glass. I called the manufacture, Douthitt Corp (Detroit,
>MI; USA) about replacement glass which they sell (and guarantee), but it
>isn't cheap.
>
>I was wondering if anybody here is a "glass" expert; being able to
>provide some guidance or point me to some references on glass for
>frames? Browsing through the archives I came across a post from Luis
>in which he warned about using glass that was not flexible enough in
>vacuum frames. Also, I stumbled upon a reference which suggests using
>"water-white glass" because it does not absorb as much UV (see quote
>below). Frankly, I have never heard of "water-white glass." Are
>there really glasses which are designed to transmit more spectral
>energy in the UV portion of the spectrum?
>
I am not a glass expert at all, but I do know of someone in the UK who
imported a very expensive glitzy UV source/vacuum frame for (primarily)
platinum work. When his glass cracked he just went to the local glazier (is
that how you spell it?) and got a piece of ordinary glass of the correct
size and thickness. He carried on printing with no discernable difference
to the results! Maybe glass type is not THAT crucial, provided the glass
does not haveany funny screening properties....
It occurs to me that if you are really worried about this, it might be
worth paying for new glass NOW, in order to avoid the risk of having to
make some sort of adjustments to all the exposure readings you made for
months'/years'-worth of printing, sooner or later the glass will finally
crack all the way across, no doubt spoiling a very large platinum print and
wasting lots of lovely chemicals...
Jonathan Anderson