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

Paul wrote:

> About 3 months ago I mixed up 50ml of 26% GA solution adding 1ml of
> 10% tea tree oil in alcohol.

This sounds like an awful lot of preservative to me. I'd expect to put
1 ml of 10% tea tree oil (or 1 or 2 drops of tea tree oil without the
alcohol) into at least 500 ml of solution, maybe even a liter. This
would probably make olfactory tests easier, too!

> 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.

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.

Best regards,