Dissolving ferric oxalate

Rvhj · Jan 5, 2023

Hello,
I went through the old post but I couldn't find helpful answers . From where I live i do not get premixed chemicals for a platinum palladium process. Importing chemicals is not economically for me.

I bought ferric oxalate powder , oxalic acid powder , 30% hydrogen peroxide. Mixed according to the following formula 55 ml of distilled water ,16 gram of ferric oxalate , one gram of oxalic acid and two drops of 30% hydrogen peroxide at 40 to 50 celsius. I cannot get it to dissolve.
I have attached the picture of the result I could attain

Any help is appreciated.

koraks · Jan 5, 2023

Rvhj said:
Mixed according to the following formula 15 ml of distilled water ,16 gram of ferric oxalate , one gram of oxalic acid and two drops of 30% hydrogen peroxide at 40 to 50 celsius.

Where does this formula come from?

The oxalate concentration sounds high. Most sources of the pre-mixed solution are in the 25% range. You seem to be aiming at more than twice that.
This source mentions stirring for 8 hours to get a 25% solution with 2% oxalic acid to dissolve completely: https://jkschreiber.wordpress.com/platinumpalladium-notes/formulary-for-ptpd-printing/

How long did you stir yours?

I'm also puzzled at the total volume of your solution (for lack of a better word). You mention 15ml + 16g, but the volume I see in that beaker seems to be far more than this. Did you scale up the formula?
Not that it helps now, but when messing with new-to-me chemistry, I always start out with very small volumes to test the principle and only scale up once I've figured out how it works.

Btw, welcome to Photrio

Rvhj · Jan 5, 2023

koraks said:
Where does this formula come from?

The oxalate concentration sounds high. Most sources of the pre-mixed solution are in the 25% range. You seem to be aiming at more than twice that.
This source mentions stirring for 8 hours to get a 25% solution with 2% oxalic acid to dissolve completely: https://jkschreiber.wordpress.com/platinumpalladium-notes/formulary-for-ptpd-printing/

How long did you stir yours?

I'm also puzzled at the total volume of your solution (for lack of a better word). You mention 15ml + 16g, but the volume I see in that beaker
seems to be far more than this. Did you scale up the formula?
Not that it helps now, but when messing with new-to-me chemistry, I always start out with very small volumes to test the principle and only scale up once I've figured out how it works.

Btw, welcome to Photrio

Sorry it was a typo error. Its 55ml of distilled water.

My source
https://www.laboldtech.eu/metodiche/platinotipia-platino-palladio/

Platinum Palladium Printing — Studio Q Photography

Platinum Palladium Chemistry and Recipes printing from Wet Collodion Negatives.

studioq.com

I stirred for 1 hr.
Stiring for 1 hour was boring enough. How is it possible to stir for 8 hours?!

Thank you, happy to be here

Herzeleid · Jan 5, 2023

Looking at the color of the precipitate, you have ferrous oxalate, not ferric oxalate. Are you certain that it is ferric iron? Preparing ferric oxalate from ferrous oxalate, oxalic acid, and hydrogen peroxide is a bit tricky. Since peroxide decomposes some of the oxalic acid to carbon dioxide and water in the end you might need more oxalic acid and peroxide. It is not a straight dump-and-mix procedure with ferric oxalate preparation.
I found this method helpful when I started trying to make my own FO.

http://www.ericneilsenphotography.com/free_papers/Ferric%20Oxalate%20Making%20Liquid.pdf

But if you can find the text for the method below it is far superior but it would take at least 2-3 days to prepare. It uses Ferric Nitrate and oxalic acid since nitrate ions are oxidizing there is no need for hydrogen peroxide. This reaction produces nitric acid so it will disintegrate paper filters. You can also find information on the method in Platinomicon by Mike Ware, page 301. (3rd method)

PREPARING FERRIC OXALATE POWDER (by Vicente-M. Vizcay Castro, August/1999)
(English revision and adaptation by Jeffrey D. Mathias)

Rudeofus · Jan 5, 2023

Rvhj said:
Stiring for 1 hour was boring enough. How is it possible to stir for 8 hours?!

Look for "magnetic stirrer". These are little devices (form factor and appearance like a kitchen scale), in which a motor in the base spins a magnet. You can put a beaker with liquid on the platform, and a little magnet covered in plastic will spin inside that beaker, driven by the spinning magnet in the base.

With such a device you can stir for weeks without getting bored.

nmp · Jan 5, 2023

Per LabOTech, it is better to use excess water to start, dissolve and then evaporate to proper composition. So they start with 27 gr in 120ml water, that's like 23%. You are starting out at around 29%. But you should still get some into the solution. From the looks of it, there does not seem to be any. Serder may be on to something. Please do confirm you do not have ferrous by mistake, although I am not even sure you can get ferrous from the usual suppliers.

Also in situations like this, it is better to add the powder slowly while stirring - not water to the powder because the solids tend to clump up that way and then they become impossible to dissolve no matter what you do afterwards. Add a little powder, stir and let it thoroughly wet (or better yet, let it dissolve) before adding more.

As mentioned, magnetic stirrer is useful for this. Get the one with heating element so you can keep the solution warm while you let stir hours on end, if you have to.

:Niranjan.

Alan9940 · Jan 5, 2023

I'd have to pull out my notes for the exact recipe I use--something like 6.2g FO powder to 25ml distilled water--but, what I do is put the FO powder into a small brown glass bottle, pour in 25ml of warm distilled water, shake it up a bit, then put it in my pants pocket for the day. My usual daily activities mixed it up pretty well. Then, I give it a good shake before bed and it sits overnight. It's usually good to go after about 24 hours.

nmp · Jan 5, 2023

Alan9940 said:
I'd have to pull out my notes for the exact recipe I use--something like 6.2g FO powder to 25ml distilled water--but, what I do is put the FO powder into a small brown glass bottle, pour in 25ml of warm distilled water, shake it up a bit, then put it in my pants pocket for the day. My usual daily activities mixed it up pretty well. Then, I give it a good shake before bed and it sits overnight. It's usually good to go after about 24 hours.

One good thing about this method is it allows for a rigorous shaking that is much more effective than a beaker and a stirring rod. Get a bottle with good cap with a plastic liner (or Saran wrap works too) so there is no contamination.

:Niranjan.

Rolleiflexible · Jan 5, 2023

Your water is too cold. Instead of 50C, boil the water. The ferric oxalate will dissolve straight away.

Rvhj · Jan 5, 2023

Herzeleid said:
Looking at the color of the precipitate, you have ferrous oxalate, not ferric oxalate. Are you certain that it is ferric iron? Preparing ferric oxalate from ferrous oxalate, oxalic acid, and hydrogen peroxide is a bit tricky. Since peroxide decomposes some of the oxalic acid to carbon dioxide and water in the end you might need more oxalic acid and peroxide. It is not a straight dump-and-mix procedure with ferric oxalate preparation.
I found this method helpful when I started trying to make my own FO.

http://www.ericneilsenphotography.com/free_papers/Ferric%20Oxalate%20Making%20Liquid.pdf

But if you can find the text for the method below it is far superior but it would take at least 2-3 days to prepare. It uses Ferric Nitrate and oxalic acid since nitrate ions are oxidizing there is no need for hydrogen peroxide. This reaction produces nitric acid so it will disintegrate paper filters. You can also find information on the method in Platinomicon by Mike Ware, page 301. (3rd method)

PREPARING FERRIC OXALATE POWDER (by Vicente-M. Vizcay Castro, August/1999)
(English revision and adaptation by Jeffrey D. Mathias)

There is no way for me to confirm if its is ferric or ferrous. I just trust manufacturer that I am provided the right chemical. I want to keep everything as simple as possible but I will resort to synthesizing ferric oxalate as the last resort.

I have read in this forum that Ferric oxalate can be a reddish brown powder. I think it was said by k sullivan.

Rvhj · Jan 5, 2023

Rolleiflexible said:
Your water is too cold. Instead of 50C, boil the water. The ferric oxalate will dissolve straight away.

All the receipts asked for water at 40 to 50 degree Celsius. I can try boiling the water. Will it damage the molecule ?convert it to ferrous form or something?

Rvhj · Jan 5, 2023

nmp said:
Per LabOTech, it is better to use excess water to start, dissolve and then evaporate to proper composition. So they start with 27 gr in 120ml water, that's like 23%. You are starting out at around 29%. But you should still get some into the solution. From the looks of it, there does not seem to be any. Serder may be on to something. Please do confirm you do not have ferrous by mistake, although I am not even sure you can get ferrous from the usual suppliers.

Also in situations like this, it is better to add the powder slowly while stirring - not water to the powder because the solids tend to clump up that way and then they become impossible to dissolve no matter what you do afterwards. Add a little powder, stir and let it thoroughly wet (or better yet, let it dissolve) before adding more.

As mentioned, magnetic stirrer is useful for this. Get the one with heating element so you can keep the solution warm while you let stir hours on end, if you have to.

:Niranjan.

Alan9940 said:
I'd have to pull out my notes for the exact recipe I use--something like 6.2g FO powder to 25ml distilled water--but, what I do is put the FO powder into a small brown glass bottle, pour in 25ml of warm distilled water, shake it up a bit, then put it in my pants pocket for the day. My usual daily activities mixed it up pretty well. Then, I give it a good shake before bed and it sits overnight. It's usually good to go after about 24 hours.

Thanks for the options guys. I will update you the results.

I will try using boiling distilled water 1st.

Rolleiflexible · Jan 5, 2023

I am not a chemist but I don’t think those atoms are that delicate. I buy the powder from Artcraft. Its instructions say to heat the water to a “scorching” 190F to 200F temperature before mixing. Elsewhere, I recall Dick Sullivan (of B&S) writing that B&S uses boiling water to force ferric oxalate into solution, but I can no longer locate the quotation and am writing from memory. FWIW I have been using boiling water for the past year and my Kallitypes are not lacking in photosensitivity.

Rvhj · Jan 5, 2023

Rolleiflexible said:
I am not a chemist but I don’t think those atoms are that delicate. I buy the powder from Artcraft. Its instructions say to heat the water to a “scorching” 190F to 200F temperature before mixing. Elsewhere, I recall Dick Sullivan (of B&S) writing that B&S uses boiling water to force ferric oxalate into solution, but I can no longer locate the quotation and am writing from memory. FWIW I have been using boiling water for the past year and my Kallitypes are not lacking in photosensitivity.

Lemme try this

Rolleiflexible · Jan 5, 2023

BTW, ferric oxalate is toxic. Be sure to use care when mixing.

Rvhj · Jan 13, 2023

Rolleiflexible said:
Your water is too cold. Instead of 50C, boil the water. The ferric oxalate will dissolve straight away.

Added 16 grams of ferric oxalate 1g of oxalic acid in 55 ml of boiling distilled water. Didn't dissolve

Rvhj · Jan 13, 2023

This is what I have

koraks · Jan 13, 2023

Here's a video that shows the ferric oxalate that's available from LabOldTech in Italy: Yours looks decidedly different. I have severe doubts that what's in that jar matches what it says on the label.

Rvhj · Jan 13, 2023

Tried 16 grams of ferric oxalate 1 gram of oxalic acid in 200 ml of water. Didn't dissolve

Rvhj · Jan 13, 2023

koraks said:
Here's a video that shows the ferric oxalate that's available from LabOldTech in Italy: Yours looks decidedly different. I have severe doubts that what's in that jar matches what it says on the label.

Rvhj · Jan 13, 2023

I also doubt about what I have. I also read in this forum that pure ferric oxalate is a fine reddish brown powder. Let me try to find that link

Rvhj · Jan 13, 2023

Making Ferric Oxalate | Photrio.com Photography Forums https://www.photrio.com/forum/forum/threads/making-ferric-oxalate.16881/post-233907

"Pure FO powder is the familiar yellow brown dust." This is quoted by Kevin sulivan from B&S.

This is the only ferric oxalate I could find. Maybe I should visit some organic chemistry professors nearby and confirm.

koraks · Jan 13, 2023

If you could get help from someone in the field of chemistry, that would of course be great!

Rvhj · Jan 13, 2023

koraks said:
If you could get help from someone in the field of chemistry, that would of course be great!

Rolleiflexible · Jan 13, 2023

FWIW the ferric oxalate I buy from Artcraft is a pale green. At least I think it is, being partly colorblind. Mine looks nothing like yours. I know there is some ambiguity to the chemistry but I would be surprised to find that the color changes from source to source.

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