[Alt-photo] Re: lump gum

[Guido Ceuppens]

Laura,

I used the following procedure with lumps of gum:

300 grs of gum are slowly dissolved in 850 ml of cold water, this may take
several days. The impurities are then filtered or fished out, some
recommend to suspend the lumps of gum in a muslin bag to prevent the
impurities to float in the solution. Once dissolved a preservation agent
must be added to the solution: in the past I have added either 15 ml of
formol or 7.5 grs of sodium benzoate. I have used the thus prepared gum for
years without it going bad (I mainly use casein now but occasionally use
gum that was prepared from powder –same procedure- 7 years ago).

Welcome back and good luck,

Guido

______________________________________________

> Alt-photo-process-list | altphotolist.org
>