Clearing of iron compounds

Gasparinho (nop51076@mail.telepac.pt)
Fri, 31 Jan 1997 21:27:10 +0100

On Jan 30 1997 Richard Sulivan said:

>It is my guess that in some cases there are secondary compounds that are
>formed during coating and development that are insoluble in one or more of
>the clearing agents. Ferric acetate appears to be one of these, and it is
>generated by the use of acetate developers that have small quantities of
>free acetic acid.

I remember reading something similar in the past, and since then when I use
acetate developers for my kallitypes, I always add a small amount of either
sodium or potassium carbonate, until a have a pH of about 8, and then
proceed with adding tartaric acid until I reach my working pH 3. Addind
oxalic acid also produces interesting results.

Clearing became much simpler since I adopted this procedure.
I must be getting old. I had almost forgotten why I do it!
Carlos Gasparinho
nop51076@mail.telepac.pt

http://members.tripod.com/~CarlosGasparinho/