Is very acidic Ferric Oxalate a problem - Clearing Kallitypes
Oh man, I'm practically pulling my hair out trying to produce a Kallitype with nice clean whites.
Here's my process:
Mixing 10 drops of each FO & SN into a solution and brushing on Cott paper - taking about 10 seconds of brushing with a Richeson 'Magic Brush'.
Leaving the paper to dry flat for 5 minutes and then 30 minutes hanging to dry.
Exposing in a Nuarc 26-1K
Developing in Sodium Citrate with potassium dichromate 2ml/litre.- citric acid added to bring up acidity - 8 minutes
Cleared in Citric Acid Baths - X2 total of 8 minutes
Toned in Gold Thiourea - 4 minutes
Fixed in Sodium Thio. - 2 minutes.
washed - 30 minutes.
The FO solution was made less than a week ago, from FO from B&S. It was made without hot water (magnetic stirrers are awesome!) and has been stored in the fridge.
The prints are not 'almost completely clearing of stain" coming out of the developer (as Sandy K. says they should). When dry, the test prints have a slight yellow in the highlights.
I have also tried Ammonium Citrate/Sodium Acetate developer which is recommended in Christopher James' book for solving the problem of buff coloured highlights.
- The developer appears to be around PH5, slightly more acidic than it should be (PH6). How would I make it more alkaline?
- The FO solution has a PH of 1.5? This seem extra-specially acid? This may because my distilled water is about PH 4.5!
- The SN solution is fairly old (2007) but I don't think that would cause staining? My Silver Nitrate crystals were given to me by a friends and are most likely fairly old.
- I have the Nuarc surrounded by black-out material, so it does get hot in there. Could heat be a problem?
- Perhaps I need to try another brand of distilled water?
Thanks for your help. I hope to solve this problem before I pull out all of my hair!
Have you tried a different paper?
I have used other papers.
Yes, I have used other papers. I was originally using Platine but it was not clearing. I've also recently tried Buxton and Herschel which seemed to be clearing fairly well but not upon close inspection. Also, the texture of the papers wasn't working with my current project. I do quite like the Cott paper, as it's a brighter white with a smooth texture.
Though it's close, the Cott is not completely clearing; the whites are buff. This shows when the test print is scanned.
It's close thought, really close. So I'll keep working on it.
I'm concerned about the acidity of my FO solution though? Is that normal?
Perhaps try some EDTA after the initial citric acid clearing baths. Tablespoon/liter should do. I've never had a problem with cot 320, but you might give a minute or two soak in a 3% oxallic acid solution prior to coating and see if that helps. Your process looks fine to me, sometimes the stars don't align and cause havoc for some reason,
Originally Posted by Erik L
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Have you tried developing without the potassium dichromate?
Last edited by cliveh; 10-08-2013 at 08:33 PM. Click to view previous post history.
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Originally Posted by cliveh
Looking back at my notes, I did try developing half the print with potassium dichromate and the other without, but that was with ammonium citrate/sodium acetate dev.
The one without had much worse stain. Even the one with, had noticeable stain.
I will try this with sodium citrate developer, doing the same type of test.
I have used EDTA disodium and it does help. Sandy King suggests that the print should have most of the stain removed by the developer. So I'm focusing on that. Perhaps I will try the oxallic acid soak on the paper. Though it seems that the oxalic acid is primarily helpful in creating deeper blacks. Though the Cott is supposed to be a very neutral ph paper, perhaps my Cottt has been compromised? and needs to be acidified?
Originally Posted by Erik L
What color is your SN solution? I'm having a very similar issue with the Athentype and realized that I have way more precipitant than I recall in the past. EDTA helped quite a bit with mine, but somewhat in the same boat as you. I'll escalate this discussion to Dick Sullivan Thursday night and see what he has to say.
My Silver Nitrate solution appears pretty much clear. It was made in 2006 and is in a small brown bottle which has been kept in the dark.
Originally Posted by Klainmeister
I'm curious about this Athenatype process. Could someone please tell me it's benefits over the kallitype/vandyke/argyrotype processes. Does it clear better and have better dmax? How does that work chemically?
Most of which I found has to do with the fumed silica aspect and not the actual process.