Richard Knoppow (dickburk@ix.netcom.com)
Fri, 29 Jan 1999 02:49:22 -0800
At 11:43 AM 1/29/99 +0100, you wrote:
>
>Dave and Liam:
>
>Thanks for the clear answers regarding hardening of gelatine emulsions, I
>think I understand the concept. Leaves me with one more question though.
>I've got some bottles with Ilford Hypam rapid Hardener which I believe
>contain Alum, which is Aluminium Oxide (Hydroxide?..have a book somewere
>where I can look it up..). So this Alum can also harden a gelatin
>emulsion I presume, but can it also prevent digestion by micro-organisms?
>(and be an alternative for Glyxol or Formaldehyde (which is obviously
>forbidden, although we have quite a few big containers in the lab for
>other purposes...) hardening of sized papers. I suppose not, I think that
>introducing salts in paper for gum etc. is not a good idea..
>
>
>Cor Breukel
>
>http://ruly70.medfac.leidenuniv.nl/~cor/cor.html
>"The Infrared Gallery"
>http://ruly70.medfac.leidenuniv.nl/~cor/ir-gallery.html
>
>
>
>
Alum in reference to the hardening agent is Potassium Aluminum Sulfate.
So called Chrome Alum is Potassium Chromium Sulfate
----
Richard Knoppow
Los Angeles,Ca.
dickburk@ix.netcom.com
This archive was generated by hypermail 2.0b3 on Sat Nov 06 1999 - 10:06:45