Re: Copy of: buying Gum Arabic

Martin Becka (marbecka@club-internet.fr)
Wed, 29 May 1996 15:15:07 +0200 (MET DST)

>>From: akleiman@infoabc.com (Alan Kleiman)
>>Subject: Re: Copy of: buying Gum Arabic
>>>------------------------<included message follows>----------------------
>>>
>>>> From: gayster@micronet.fr (gayster alain)
>>>> Date: Sun, 26 May 1996 19:05:49 +0200 (MET DST)
>>>> Subject: Re: Copy of: buying Gum Arabic
>>>
>>> On Thu, 23 May 96 Judy Seigel wrote about gum conservation :
>>>
>>>>You will need to keep it in the fridge.
>>>
>>>Yes, indeed.
>>>
>>>>Why not add a few drops of formaldehyde (maybe gloxal works too) or
>>>>thymol? My home-mixed gum is a year old and still fine with
>>>>formaldehyde added.
>>>
>>>You may also add some salicylic acid (you can get it in chemist's shop).
>>>It is used to preserve jam and other food. So it is safe.
>>>
>>>Alain

Alan Kleiman wrote

> How much salicylic acid.

L.P.Clerc in "La Technique Photographique"(1942) wrote
Add 2 or 3 g salicylic acid to 1000 ml mixed gum
( 500 g gum add water to make 1000ml )

H.Schneeberger in "Les procedes au charbon"(1937) wrote
Add 5 g salicylic acid to 1000 ml mixed gum

C.Puyo in "Le procede a la gomme bichromatee" (1904), and A.Maskell et
R.Demachy in "Le procede a la gomme bichromatee" wrote that's better work
with fresh mixed gum.

I add to my home-mixed gum ( 500 g gum, water to make 1000ml ) 3 g
salicylic acid.I print trichrome or polychrome gums and I have in my lab
many bottles, some of them are 1 year old and I can work fine with them.

>Dose salicylic acid disolves in water.
> Alan Kleiman
> akleiman@infoabc.com
>
The salicylic acid is wery litte soluble in cold water, but dissolves
easily in hot water.

Martin
--------------------------
marbecka@club-internet.fr
--------------------------