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 film) - 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, Loris. -----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
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