I thought that you were saying in earlier post on the subject of ferric
oxalate that extra oxalic acid was good? and now it is the cause of the
formation of silver oxalate? It is also recommended by Pizzighelli in
his writings, 6 to 8 g per 100ml?
I thought that the formation of silver oxalate was due to extra oxalate
ions in solution and that the addition of ferric nitrate prevented its
formation.
> The way to solve this problem is to add small quantities of a concentrated
> solution of ferric nitrate to it while stirring. Keep testing a small
> amount of the FO until a drop of silver goes in clean and doesn't make a
> cloudy precipitate. You do want to overdo it, as this will leave a trace of
> nitric acid in the solution. The nitric acid will act as a contrasting
> agent. Do this with a small clear beaker or test tube. Now you can add the
> silver nitrate.
This does work and I thank you for the ferric nitrate that I acquired
from you that allowed me to being using my ferric to make kallitypes.
>
> I think this free oxalic acid problem is one of the reasons that Kallitypes
> have not enjoyed much popularity in the modern era. Folks have not been
> able to get the proper materials and none of the printed modern articles on
> the Kallitype mention this other than the totally disorganized and
> unreadable Dick Steven's book. "Making Kallitypes." I think it is in there
> but if it can find it, you may deserve a hundred dollar prize.
Dick, It is in the chapter that follows how to make ferric. It goes
like this: How to make ferric, then how to make it work with Kallitypes,
I believes he titles it Optimizing the Sensitizer. He also share his
experience of how much ferric nitrate to add and how it changes his
prints. (a rate of .15g Ferric Nitrate/3ml Ferric Oxalate)
You can send the $100 any time or should I contact Dick and Ed.
-- Eric J. Neilsen 505-758-8868 http://laplaza.org/~ejnasn