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

I hear ya, about the smell of soured gum arabic. The first time I mixed up
the stuff from powder I trusted the old lit that said yes, it soured, but it
worked just fine. YES it worked fine, but every time I used it I literally
gagged! It is the WORST frikkin' smell, almost as bad as putrifying meat.

Anyway, I am really interested to know about tea tree oil. I wonder if it
is oily at all, and if you get "fish eyes" in your gum coats--the coat
separates into swiss cheese looking holes. Please keep us posted when you
use it, or if you want, send me a little vial of the stuff and I'd be
willing to test it at the same time, too.

I use thymol--i get 10 grams of the stuff and mix it up with 10ml of
alcohol. It works great and i never get mold in my gum. But it is very
fragrant, and so when I open up my tupperware box full of gum supplies and
that little envelope of thymol crystals is in there, it's like getting a
jolt of a headache remedy or Vicks Vaporub. But it works great and isn't
very expensive and a little goes a looooonnnnngggg way.

But I am very interested in your tea tree oil test because I think you can
buy that at a drug store, correct?
PS since there are so many options in development etc. the fact that a more acid gum might be faster has never been an issue in my practice so that I have noticed differences between them all, and I mix my own or use store bought and lately have been using up some 6 yr old stuff I came across...
----- Original Message ----- From: "Arcus, Paul" <Paul.Arcus@dsto.defence.gov.au>
To: <alt-photo-process-l@usask.ca>
Sent: Wednesday, October 04, 2006 5:00 PM
Subject: Non-nasal identification of 'off' gum arabic solution

Some time ago I posted a thread about the use of tea tree oil as a
preservative for gum arabic (GA) solution.
As tea tree oil is easy to source I wanted to use it for preservation of
GA solution mixed from powdered GA (because I cannot source formalin or
Tea tree oil is also a natural antiseptic, anti-bacterial, non-irritant
and soluble in alcohol so it may provide a good alternative.

As I live in the tropics GA solution with no preservative stored at room
temperature usually smells worse than cat excrement after about 10 days.

It also goes cloudy and / or gains a nice crust of green mould.

About 3 months ago I mixed up 50ml of 26% GA solution adding 1ml of 10%
tea tree oil in alcohol. I also made a batch with no preservative.
The non-preserved GA went bad after 11 days. It went yellowish, cloudy
and stank like 7 pairs of old socks kept warm in a plastic bag.

To date the GA / tea tree oil solution appears a tiny bit cloudy but has
no visible mould.
The smell of tea tree oil is overpowering so I am unable to judge its
efficacy by smell.

I'm hoping soon to make some prints using the GA / tea tree solution.
I would also make side-by-side comparison with non-preserved (fresh) GA

Elsewhere I've read that the properties of GA solution change with age
(clearing, staining, etc).
Noting these ageing effects and noting that I cannot judge it by smell
how would I know if the solution is bad due to ageing / contamination or
some other factor?