U of S | Mailing List Archive | alt-photo-process-l | RE: Newbie Gum fun!

RE: Newbie Gum fun!

Hi Jacek, won't comment about Arches since I have no experience with
that paper but I know that Fabriano Artistico is a good paper for gum
(use HP for more a photographic look).

My method of mixing gum solution from powder is:
- Weigh 100g gum powder
- Weigh 200g (200ml) distilled water (= 2 x gum -> interpolate according
to gum weight)
- Weigh 2.5g Sodium Benzoate (= 2.5% x 100g gum -> interpolate according
to gum weight)
- Mix Sodium Benzoate into distilled water (= sodium benzoate solution)
- Mix gum powder into sodium benzoate solution, stir thoroughly breaking
lumps / aggregations at least 10-15 minutes 
- Close the mouth of the vessel (with its original cover or using cling
- Wait few hours until most of the liquid is free from froth (I usually
mix gum in the evening and wait until next morning)
- Pour slowly / carefully to the final container (paying attention to
not transfer the last bits of froth)

I still have 5 months old gum solution that looks and smells same as the
first day it was mixed...

BTW, not that I give importance but my gum powder is white, not yellow
-> probably because it's more finely ground than yours...

Hope this helps,

-----Original Message-----
From: Jacek [mailto:gonsaj@iinet.net.au] 
Sent: Monday, April 16, 2007 11:17 AM
To: alt-photo-process-l@usask.ca
Subject: Newbie Gum fun!


I have bought the powder form of Gum Arabic, its a straw yellow. I tried
two methods, to make a 35% solution in 100ml (35g of gum). 
The first method was to use a coffee filter and put 35g of that in there
and poured distilled water to make 100ml out of it. There was one big
gooey mess in the filter. Which I threw away once I got my 100ml. 

The other method was to put the gum 35g in 100ml of water, when I did
this I thought there was no way the gooey mess will actually dissapear,
but as an hour or so progressed it started slowly disappearing! :) I'll
check on it tonight, and might pass that 100ml through a coffee filter
to see if any sediment is caught and throw that away.

What methods do you use to make a solution of gum arabic from powder?
Many thanks Jacek Gonsalves