Re: What do you think of...

Judy,

Keith Howard's book -Safe Photo Etching for Photographers and artists-
explains a cumbersome method of creating images on copper plates with a
gelatin bichromate solution as the etching resist. One of the methods of
application is by spraying on the sensitized gelatin with an airbrush. He
claims that the Alberta (Canada) Government occupational safety folks tested
the air in a room in which "a large copper plate was sprayed continually for
2.5 hours and the overspray tested. Results: overspray aprox "55 times lower
than the minimum acceptable standard level of the Alberta occupational
standard". The test measured the area for a ten foot radius around the spray
site. So I interpret that to mean that no exhaust hood was used. He mentions
using a spray booth but says its not necessary. His argument seems to be
that the bichromate is diluted in the solution. Since he is hardening the
gelatin with the bichromate the material is fundamentally the same as gum
bichromate solution.

I'm not sure I'm ready to start spraying the stuff around in my studio but
it is interesting...

Jack

> From: Judy Seigel <jseigel@panix.com>
> Reply-To: alt-photo-process-l@sask.usask.ca
> Date: Tue, 13 Dec 2005 00:10:22 -0500 (EST)
> To: alt-photo-process-l@sask.usask.ca
> Cc: alt-photo-process-error@sask.usask.ca
> Subject: Re: What do you think of...
>
>
>
> On Mon, 12 Dec 2005, Peter Marshall wrote:
>> He also recommended the use of an air brush (foot powered in those days) to
>> coat paper evenly.
>
> Dichromate via airbrush should of course only be done with fume hood &
> mask.... and then only if you're already dead.
>
> J.
>
>
Received on Tue Dec 13 10:14:19 2005