Mixing Powdered Gum Arabic

Andrew O'Neill

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Anyone have experience doing this? Mind sharing your procedure? I need to to work with 14 Baum. I no longer can purchase in quart sizes at my local art store. Instead they've got these dinky little bottles of a really thin looking stuff.
 

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Hi Andrew

I've only bought it pre-mixed but I have Christina Anderson's book and she says to
put about 300g of your powered gum into a graduate and slowly add and mix Distilled water mixing it slowly
and once it looks like paste add the remainder to bring the total volume to I L.. She says it will be cloudy but eventually clear up.
and her mixture is pretty thick.
Christoper James on hte other hand in his book says his mixture is 1:6 and suggests you can
put 30G of gum with 180cc of water and let it sit together until it enters solution on its own ( after a few days )...
Both Christina and Christopher suggest filtering out the stuff that isn't dissolved...

I'm lazy ... and don't know the concentration of the stuff that I have...

John
 
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Andrew O'Neill

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Thanks, John! I think I'll try Christina Anderson's method, as I prefer to mix up a large batch. Apparently I'll need to add a preservative as it can go bad quickly. I don't have any thymol, but I do have some stinkin' formalyn that I would like to use up.
 

ced

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Clove oil & or Lavender much nicer smelling & for sure less toxic than formol. Mine has kept for years without fungus developing.
 

Herzeleid

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My ratio for gum arabic solution is 1+3, 1 part gum 3 parts water. And I happen to have a baumemeter and my preparation is spot on 14Bé. I buy gum arabic in powdered form, I mix it with water and with a help of hand blender everything is homogenous in minutes. However mixing with a hand blender, introduces lot of air and it needs to settle. Usually the solution contains minute amounts of dirt and other impurities. I use a fine mesh filter to remove impurities and let the solution settle for a day.

I have used sodium benzoate as preservative, 0.5 gr per 100gr of gum. I have 5-6 years old gum arabic solutions in perfect condition. I use thymol for methods involving gelatine, but for gum I would not change benzoate. Since gum arabic solution is by nature acidic sodium benzoate works perfect in those ph conditions.
 

Dan Pavel

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I use crystals, not powder, diluted 40% gum+60% water (weight) and add thymol as a preserver. I prefer crystals because I can sort them and only use the clear and lighter in color ones. As a result I throw about 20-30% of the total amount of gum and my solution looks much more transparent and less colored than the pre-mixed ones. I let the crystals dilute for at least 3-4 days and after that I filter the solution 3 times before adding thymol. Filtering is a very time-consuming operation as the filter-canvas needs to be washed often. For1l of solution it will take some 3-4 hours as no more than 100 ml of solution can be poured into the funnel at once. As a result another approx. 20-30% of the solution is lost. The final solution is a bit less dense than the starting one and that's why I start with a 40% gum-60% water dilution. Stored in the refrigerator it will last for years.
 
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Andrew O'Neill

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Mixed up a batch. 1+3. Used my wife's mixer D). All went into solution easily in a few minutes. Let the frothy batch sit covered in the counter until all froth gone. Added a measured amount of sodium benzoate, which eventually absorbed into the gum solution. It wouldn't stir in, so leaving it in the gum solution for an hour or so, absorbed it.
Made a test print this morning. Very satisfied.
 

Herzeleid

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Good to hear all went well. Proof is in the pudding, That is a good looking print.
 

Debanjan

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In case you do not have distilled water handy, please boil normal water first and then once it cools down a bit, you can do the mixture in exactly the same way as other posts had suggested. I do not have easy access to distilled water and found that driving out the oxygen from water prevents fungal growth totally .. the free air in the bottle above the solution doesn't impact much..
 
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