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 am aware of Tea Tree Oil via my massage therapist, but she doesn't use it in massage oils.  I know it is STRONG and I wouldn't want to get it in my eye or anyother little nook or cranny!  But I am not surprised that it will do what you say.  I imagine a small amount would do it. 

Best Wishes,
Mark Nelson

Precision Digital Negatives - The System
PDNPrint Forum at Yahoo Groups

In a message dated 10/4/06 6:12:36 PM, Paul.Arcus@dsto.defence.gov.au writes:

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?