U of S | Mailing List Archive | alt-photo-process-l | Re: Non-nasal identification of 'off' gum arabic solution

Re: Non-nasal identification of 'off' gum arabic solution



From: etienne garbaux <photographeur@nerdshack.com>
Subject: Re: Non-nasal identification of 'off' gum arabic solution
Date: Wed, 04 Oct 2006 22:48:20 -0400

> It would be interesting to prepare two more batches -- one that has
> just a drop or two of tea tree oil, and one that has just 1 ml of
> alcohol, which is also an antiseptic, to see whether tea tree oil or
> alcohol is a more effective preservative.

The bactericide effect of ethanol or 2-propanol drops very
significantly below 70% concentration and is very weak below 50%
concentration. At a concentration below 0.2% it's useless for such a
purpose.

I personally don't understand why people want yet another biocide
after knowing dozens of agents that are inexpensive, effective, and
easy to use. This topic came up many times but I've never heard of a
case where a new biocide enabled a new kind of photography or
anything...

http://wiki.silvergrain.org/wiki/index.php/Biocides