Sodium Carbonate

Jaq · Mar 27, 2008

Hi

I recently was given a large bucket of sodium carbonate. I know that this chemical is used in a photographic process, I just can't find out which one from the internet.
Do any of you know? :confused:

Thanks for the info.

Regards,

Emile

juan · Mar 27, 2008

I use it in developers - both film and paper. Agfa, IIRC, had some fixer formulas that used it.
juan

Rlibersky · Mar 27, 2008

It is used in just about every developer as an accelarator.

Mike Wilde · Mar 27, 2008

paper developers for sure

sod carb is used in all sorts of b&w paper developers.

Dektol 1l stock solution - diluted between 1:1 and 1:4 - from memory - is about:

3g metol (or 0.3g phenidone) , 45g sodium sulfite, 12g hydroquinone, 70g Sodium Carbonate, and then 2 -4 g of Potassium Bromide.

CBG · Mar 27, 2008

Rlibersky said:
It is used in just about every developer as an accelarator.

Not quite, but very many. It is as noted before an "accelerator" for developers. In plain terms, an alkalai, since all common developers* will not function in a neutral or acidic environment.

* except amidol

Common accelerators are:
Sodium Sulfite
Borax
Sodium Metaborate
Sodium Carbonate
Potassium Carbonate
TSP Tri sodium Phosphate
Sodium Hydroxide
Potassium Hydroxide

Sodium Carbonate is used in something roughly like half of the several hundred developer formulas I have in my computer (don't ask, it's an obsession)

It's also used in some toners and a small miscelany of other photograpic processes,

Best,

C

dpurdy · Mar 27, 2008

CBG said:
Not quite, but very many. It is as noted before an "accelerator" for developers. In plain terms, an alkalai, since all common developers* will not function in a neutral or acidic environment.

* except amidol

Common accelerators are:
Sodium Sulfite
Borax
Sodium Metaborate
Sodium Carbonate
Potassium Carbonate
TSP Tri sodium Phosphate
Sodium Hydroxide
Potassium Hydroxide

Sodium Carbonate is used in something roughly like half of the several hundred developer formulas I have in my computer (don't ask, it's an obsession)

It's also used in some toners and a small miscelany of other photograpic processes,

Best,

C

I don't think sodium sulfite is ever going to get your developer going. I know I mix my paper developer with a bunch of sodium sulfite and sodium carbonate and if I leave out the sodium carbonate the developer doesn't do a darn thing regardless of how much sodium sulfite it has in there.

Anscojohn · Mar 27, 2008

Jaq said:
Hi

I recently was given a large bucket of sodium carbonate. I know that this chemical is used in a photographic process, I just can't find out which one from the internet.
Do any of you know? :confused:

Thanks for the info.

Regards,

Emile

Ascertain in what form is the sodium carbonate (anhydrous? monohydrate? crystal?). It can be used to make up most paper developers, some (few) film developers.

Also, a 2 % solution after print fixing and before washing of fiber-based papers speeds up your wash time.
John, Mount Vernon, Virginia USA

gainer · Mar 27, 2008

dpurdy said:
I don't think sodium sulfite is ever going to get your developer going. I know I mix my paper developer with a bunch of sodium sulfite and sodium carbonate and if I leave out the sodium carbonate the developer doesn't do a darn thing regardless of how much sodium sulfite it has in there.

D-23 has only Metol, sodium sulfite and water and is nearly as active as D-76. However, we seldom develop paper in D-76 either.

Jaq · Mar 27, 2008

OK, that makes sense actually. I also received a bucket of sodium sulfite, but I thought it was used only in fixers. I was slightly disappointed as I thought I had half of the ingredients. Excellent!
Do any of you know (dpurdy for example ) a formula that I could use as a paper developer using both sodium carbonate and sodium sulfite?

dpurdy · Mar 27, 2008

Just about all the paper formulas I know of use both. The one I use most for commercial work is 2.7 grams metol, 40 grams sod. sulfite, 10.6 grams Hydroquinone, 87 grams sod. carbonate, 0.8 grams Pot Bromide. Makes a liter of stock and dilutes 1:2 and lasts all day.

D-23 does indeed utilize only 7.5 grams metol and 100 grams sodium sulfite in a liter working solution. I have never tried it. But I will point out that the divided developers all store the developing agents in solution with sodium sulfite. The sodium carbonate is kept in solution by it's self. far as I know.

Photo Engineer · Mar 27, 2008

D-72, or Dektol is the most common formula out there for home mixing and usable for papers.

PE

dancqu · Mar 27, 2008

dpurdy said:
D-23 does indeed utilize only 7.5 grams metol
and 100 grams sodium sulfite in a liter
working solution.

Dilute 1:7 for a slow working semi-compensating
developer; 500ml, one 120 roll, 16 minutes. Works
well for me. Dan

tpersin · Mar 27, 2008

it's also often used to bleach cyanotypes (before toning) formula vary..... 1g Na2CO3:100ml H2O often works well....

CBG · Mar 28, 2008

Anscojohn said:
It can be used to make up most paper developers, some (few) film developers.

Slightly less than half, 240 or 42% of the 567 film developers and 140 or about 55% of 241 paper developers I have listed have Sodium Carbonate in my very unscientific query. Those numbers are less accurate than they look since there are a few duplicate formulations I have not yet weeded out and a few just plain dubious formulas I have sifted off obscure corners of the net. But I suspect the general tendency for carbonate to be used is very closely mirrored by my numbers.

C

CBG · Mar 28, 2008

Jaq said:
Do any of you know (dpurdy for example ) a formula that I could use as a paper developer using both sodium carbonate and sodium sulfite?

Check in the APUG articles under paper developers.

www.apug.org/forums/forum222

Most of those listed show sulfite and carbonate.

C

CBG · Mar 28, 2008

Anscojohn said:
Also, a 2 % solution after print fixing and before washing of fiber-based papers speeds up your wash time.

Sodium Sulfite is almost always used in home mixed wash aid. Within the several chemicals have been shown to have some effectiveness as wash aids, Sodium Sulfite is predominant. I have not seen carbonate listed among them, but can't rule it out since several alkalais are noted as having measurable benefits for washing.

One common formula for Wash Aid:

Stock Solution
Water 750 ml
Sodium Sulfite (anhydrous) 100 gr
Sodium Metabisulfite 25 gr
Cold water to 1.0 L

Dilute 1+4 for use

I gather sulfite by itself is workable as a wash aid, but do not have solid confirmation of that. Maybe one of our resident chemist experts could weigh in?

C

gainer · Mar 28, 2008

PC-TEA has neither sulfite nor carbonate. The stock contains only Phenidone, ascorbic acid and triethanolamine. Add ony water to get the working solution.

Kirk Keyes · Mar 28, 2008

CBG said:
I have not seen carbonate listed among them, but can't rule it out since several alkalais are noted as having measurable benefits for washing.

Agfa used to recommend a carbonate solution as a wash aid in the 70s. I think the idea was that increasing the pH of the emulsion would cuase the emulsion to swell, allowing the fixer to wash out faster.

CBG · Mar 28, 2008

Kirk Keyes said:
Agfa used to recommend a carbonate solution as a wash aid in the 70s. I think the idea was that increasing the pH of the emulsion would cuase the emulsion to swell, allowing the fixer to wash out faster.

Interesting. I found this comparison of chemicals used as wash aid:

Solution........................pH at M/250...............Effectiveness relative
.................................................. ....................to pure water

Demineralized water...............~6............................ ...1.0
Sodium chloride.....................6.1.......................... .....1.5
Sodium bisulfite.....................4.1................. ..............2.8
Sodium sulfate.......................6.4................. ..............14
Sodium bicarbonate................8.4.................... ............49
Sodium sulfite........................9.2....................... ........87
Sodium hydroxide...................11.6.................. ............89

I don't remember where I dug it up, but your information seems like it fits.

C

Photo Engineer · Mar 28, 2008

The table above was recently posted here on APUG, and one attribute is to Grant Haist. That progression is correct, but the potential for damage to the film or paper goes up with pH above about 8, and therefore a hardener was used in these situations.

PE

dancqu · Mar 29, 2008

CBG said:
Interesting. I found this comparison of chemicals used as wash aid:

Solution........................pH at M/250...............Effectiveness relative
.................................................. ....................to pure water

Demineralized water...............~6............................ ...1.0
Sodium chloride.....................6.1.......................... .....1.5
Sodium bisulfite.....................4.1................. ..............2.8
Sodium sulfate.......................6.4................. ..............14
Sodium bicarbonate................8.4.................... ............49
Sodium sulfite........................9.2....................... ........87
Sodium hydroxide...................11.6.................. ............89

C

I don't see any carbonate. Just what is meant by effectiveness?
Were equal molar quantities used? Times and temperatures.?
Not knowing the test parameters what are we to make of
those numbers? Dan

Paul Verizzo · Mar 29, 2008

It came from Haist, quoting other Kodak researchers

CBG said:
Interesting. I found this comparison of chemicals used as wash aid:

Solution........................pH at M/250...............Effectiveness relative
.................................................. ....................to pure water

Demineralized water...............~6............................ ...1.0
Sodium chloride.....................6.1.......................... .....1.5
Sodium bisulfite.....................4.1................. ..............2.8
Sodium sulfate.......................6.4................. ..............14
Sodium bicarbonate................8.4.................... ............49
Sodium sulfite........................9.2....................... ........87
Sodium hydroxide...................11.6.................. ............89

I don't remember where I dug it up, but your information seems like it fits.

C

It came from Haist, quoting other Kodak researchers.

The one common salt not listed which I think would be of "great" interest is sodium carbonate. I presume it would rate up there close to the hydroxide.

IIRC, Kodak HCA is sodium sulfite plus sodium bisulfite or some other acidic salt. I presume to lessen the swelling of the gelatin, which will give faster results.

CBG · Mar 29, 2008

dancqu said:
I don't see any carbonate. Just what is meant by effectiveness? Were equal molar quantities used? Times and temperatures.?
Not knowing the test parameters what are we to make of those numbers? Dan

I can't be more informative. Wish I had access to original text in full. I take it that those chemicals help wash paper in rough proportion to the "effectiveness numbers", but that said, I'm sticking with sulfite.

C

dancqu · Mar 29, 2008

CBG said:
I can't be more informative. Wish I had access to original
text in full. I take it that those chemicals help wash paper
in rough proportion to the "effectiveness numbers", but
that said, I'm sticking with sulfite. C

I see the ph was measured at a concentration of 1/250
molar. It would be a generalization to say those ph values
hold at higher or lower concentrations. I'd need to run some
numbers but can say now that M/250 is very little chemistry.
Unrealistically little; less than one gram/liter of any of the
chemicals listed. Hard to believe. Explanation?

And effectiveness? How so; maybe half the water or half
the time? Maybe half the remaining hypo using the
same wash procedure?

All in all, just some more information that leaves us
hanging; RE the discussion concerning hypo testing.
I've more to add to that thread. Dan

Sodium Carbonate

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