[Alt-photo] oxalate ferric problem

bobkiss caribsurf.com bobkiss at caribsurf.com
Mon Mar 7 03:58:28 UTC 2016

Over the years and several batches of FO soln mixed out of the same large jar of FO, I have reheated my FO repeatedly and I have given it three or four days to dissolve.  I can stick a neg in my plate burner, set the number of units on the integrator, coat my paper with the same drop count and get a very closely matching print (speed, Dmax, and contrast) as what I have gotten with previously mixed batches of FO.  Days of mixing and reheating seem to have no effect on results.  
I recall Eric Neilsen saying that some batches of FO from different suppliers dissolved much more quickly than others but I see little difference in the prints and that is all that matters to me.


----- Original Message -----
From: "alt-photo-process-list at lists.altphotolist.org" <alt-photo-process-list at lists.altphotolist.org>
To: "alt-photo-process-list at lists.altphotolist.org" <alt-photo-process-list at lists.altphotolist.org>
Cc: "Keith Schreiber" <keith at jkschreiber.com>
Sent: Saturday, March 5, 2016 4:36:57 PM
Subject: Re: [Alt-photo] oxalate ferric problem

Hi Jusdado,

Is this the same batch of ferric oxalate that you were using earlier? If so, how old is it? I mean how long have you had it? If you can’t get it to dissolve within 24 hours it is probably expired. Though I see Bob says his sometimes takes longer. In my experience if it doesn’t dissolve completely in 24 hours it is not going to. In any case, do not reheat it after it has cooled. 

On the other hand, have you tried to siphon out what you can of the dissolved portion? If so, have you tried printing with it? I did that with the batch I was having trouble with a couple weeks ago and found that it works fine for Pt/Pd. I suspect it would for Kallitype too.

~ Keith

> On Mar 5, 2016, at 1:17 PM, jusdado via Alt-photo-process-list <alt-photo-process-list at lists.altphotolist.org> wrote:
> 2nd attempt to dissolve ferric oxalate. 100 cc. distilled water at 80 / 90C. + 20 gr. ferric oxalate added slowly stirring constantly. After 2 hours, all the ferric oxalate in the container with water and stirring + 0.5 gr. oxalic acid. 2 more hour and + 0.5g. oxalic acid and stirring. 2 more hours and + 0.5 g oxalic acid and stirring. When the stirring stops, deep yellow mud, up, water with a yellowish color.
> I'll let you all night continuously agitated.
> Ferric oxalate never reaches its complete dissolution ?.

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