RE: formula needed: Gum Arabic from powder

OK, thanks all, this is more fun than I'd imagined...I found a product
-- "Dr. Scholl's Clear Away Liquid Wart Remover System" with 17%
salicylic acid by weight. It also includes "Castor Oil, Ethyl Lactate,
Flexible Collodion, Polybutene, Alcohol 18% w/w and Ether 53% v/v
(from flexible collodion)" Shoulds like it could almost be used as a
photo emulsion with the addition of some silver nitrate.

-Darryl

-----Original Message-----
From: T. E. Andersen [mailto:postlister@microscopica.com]
Sent: Wed 11/24/2004 4:05 PM
To: alt-photo-process-l@sask.usask.ca
Subject: Re: formula needed: Gum Arabic from powder
 
Ryuji Suzuki wrote:
> Adding an acid to gum solution may help a bit, especially if
combined
> with refrigeration but it can only slow bacterial growth and not
> suppress the growth or kill them. This may be ok as a short term
> preservative for edible stuff, but no good for long term, because
> yeast and fungi grow in acid environment, even if refrigerated.
> (Usually, bacteria grow faster and their growth limits the shelf
> life. If acid is used to slow them down, shelf life is now limited
by
> yeasts and molds.)

In 1996 I made a batch of gum solution that I never got round to
using.
It contains approx 0.2% salicylic acid. It has been in the fridge most

of the time, with some months now and then in room temperature. As far

as I can tell, no fermentation or fungus has developed. I don't know
if
this is typical, but if it is, salicylic acid should definitely do the

trick. It is also quite water soluble, so it should be washed out
during
processing. It is also safe to work with (you could even use it in
your
jam :-)!

Best regards,

Tom Einar