U of S | Mailing List Archive | alt-photo-process-l | RE: Gum Arabic Froth

RE: Gum Arabic Froth


I'm mixing up my first "real" batch of gum from powder (1g gum + 2ml H2O).
Cold water seems to work the best. But after the initial stirring it's very
frothy (and chunky). Is this normal? What do people do with the froth? Skim
it or let it flash off. On a 25g + 50ml batch I used 10 drops of Formalin to

Yes it is quite normal to foam. Don't skim the foam. 

How are you mixing the gum and water? With an electric blender? Using a
blender will mix the gum fairly uniformly, however and residual gum powder
left on the sides of the blender vessel should be scraped off to be blended
into the mix. Use a plastic cake icing thingy to scrape the sides. 

Don't use formalin as a preservative, instead use a few drops of a 100%
solution of thymol. Formalin will probably cause the gum to harden. After
mixing the gum pour the solution in a storage container and let it sit over
night. It will be foam free the next day. When emptying the mixing vessel
scrape all of the dry powder or chunks into your storage vessel, they will
dissolve too.

I mix about 500 ml at a time. A 75 ml batch won't last very long.

Don Bryant