Can ferric oxalate be resuscitated?
I'm planning to try my hand at making some Ziatypes and Pt/Pd prints soon and have acquired the needed chemistry. When I went to shelve them in a dark cabinet, I found some old chemistry from about 10 years ago that had never been opened. The old stuff includes:
Ferric Oxalate #2 solution
40% Ferric Ammonium Oxalate #1 solution
Ammonium Ferric Oxalate #1
Ammonium Ferric Oxalate #2
all of which look clear and greenish through the amber glass bottles. I'm assuming these chemicals are well past their useful life.
Can these chemicals be resuscitated somehow? Like maybe through the addition of oxalic acid and hydrogen peroxide? Or should I just trash them?
Also, is Ferric Ammonium Oxalate the same thing as Ammonium Ferric Oxalate?
I also found:
1% Potassium Chloroplatinate sol.
5% Gold Chloride sol.
Cesium Palladium #3 sol.
Lithium Palladium #3 sol.
Argyrotype sensitizer sol.
I assume all these chemicals will be OK. Erno?
I've used FO that was 6 months old that was too far gone. Also, I can see the ammonium FO being greenish, but not the FO. I've got a small amount of both in powdered form that I can send you this week if you need it quick. I'd go that route before trying to revive the stuff you have.
There's supposed to be a way to resuscitate FeOx, involving oxalic acid, but I forget the details. Try pinging Bostick & Sullivan for advice and specific formulae. I THINK the Ferric Ammonium and Ammonium Ferric are the same, just a different order for writing them out. The FeOx may be the one chemical though that you just toss and replace, because of all those chemicals for pt/pd you've got, it's one of the cheapest.
Thanks Bill, but I don't really need any. I have fresh chemicals. It's just that I found this old stash and since it was unopened, I was hoping there was a way to make it good again rather than just tossing it.
The ammoniums may still be OK. You could do a quick printing test on a small print and only risk a few drops of your pd solution.
The FO #2 is intended for develop-out pt/pd printing and contains potassium chlorate as a restrainer for contrast control. This is BAD stuff when it comes to making quality prints. There are much better ways to control contrast in developing-out pt/pd printing (ie not Ziatype) - Na2 in the sensitizer or dichromate in the developer.
Your other chemicals should still be OK, especially the gold, pd and pt solutions. Can't comment on the argyro sensitizer.
A good resource for identifying chemicals by their various names is www.chemfinder.com.
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According to Mike Ware, Ammonium Iron(III) Oxalate solution "...Stored carefully at room temperature in the absence of light, ... will keep indefinitely...". See:
(Subtitle: "C. Iron solution (1.4 molar)")
Probably the Argyrotype sensitizer is off. Again quoting Mike Ware: "...The solution should keep for a year, at least. If it throws down a small amount of black precipitate, it should be re-filtered...". See:
(Subtitle: "Making up the Sensitizer")
Argyrotype sensitizer is similar to Vandyke in some ways and I couldn't keep Vandyke solution more than 1 year w/o silver plating and/or precipitation and/or fog...
Originally Posted by Kerik
I think what Scott is thinking about is adding some 3% hydrogen peroxide (the household stuff) to the FO. Do NOT place the cap on tight, or bad things could happen - all those gases want to go somewhere. IIRC what happens is the ferrous goes back to ferric state. Might be something to try, don't have my copy of Arentz book handy, but am pretty sure it is in there and as was mentioned you can just call B&S.
The other stuff would be in the dark (pun intended) about what to do.