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

Non-nasal identification of 'off' gum arabic solution

  • To: alt-photo-process-l@usask.ca
  • Subject: Non-nasal identification of 'off' gum arabic solution
  • From: "Arcus, Paul" <Paul.Arcus@dsto.defence.gov.au>
  • Date: Thu, 05 Oct 2006 08:30:11 +0930
  • Comments: "alt-photo-process mailing list"
  • List-id: alt-photo-process mailing list <alt-photo-process-l@sask.usask.ca>
  • Reply-to: alt-photo-process-l@usask.ca
  • Thread-index: AcbnwgiP4axkMqyEROybsMciq5irFwAQXdWQ
  • Thread-topic: 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?