Replacement for sodium sulfite ?

[VesaL]

Hello!
i´m about to mix older color developer (CD-1 type) which one part consist(s) of sodium sulfite.
Can it be substituted for Sodium Sulfate, aka Glauber´s Salt ?

Many thanks for the kind help in advance,
Regards,
Vesa

 

[Rudeofus]

These two look similar, but behave very differently in photographic bathes. Sodium Sulfite is an essential ingredient in many photographic bathes, whereas Glauber's salt is almost irrelevant.

 

[VesaL]

Hello and thanks for the quick reply. I´l have to pass Glaubers Salt then. I do have Kodak Hypo Clearing agent in sachet, but it also contains some sodium metabisulfite, dunno does that compound have adverse effects in the developer..

-Vesa

 

[Rudeofus]

If you can find a credible source for CD-1, then you will find a good source for Sodium Sulfite much more easily. That's like one of the most basic compounds in photo chemistry, and it has many other uses. It's dirt cheap, too, so try to find a local source to keep shipping costs in check.

 

[glbeas]

Sodium sulfite can often be found at pool supply shops. Not sure if the purity is up to the task though.

 

[VesaL]

Many thanks for all who have contributed to my question, I'll check the local suppliers & pool shops
- Vesa

 

[Bob Carnie]

How would one know if the sodium sulfite from pool shops is good for our purposes?? and secondly what do pool shops do with sodium sulfite?

 

[glbeas]

How would one know if the sodium sulfite from pool shops is good for our purposes?? and secondly what do pool shops do with sodium sulfite?

Its used for modifying the chlorine level from what I remember. I bought a quart sized container of it quite a few years back, price was nothing to worry over.

 

[Wayne]

if you buy a 30 lb bag from the company that supplies the pool companies, it will say right on it what grade it is.

 

[darkroommike]

Sulfite and thiosulfite are both used to reduce chlorine levels. Sodium sulfite also used in wine-making, food preservation, etc. Food grade is good enough for most darkroom formulas. I would not hesitate to use it for a substitute HCA but in a color developer I would use photograde, source it from the same place you got your CD-1.

 

[Bob Carnie]

Interesting

 

[Ian Grant]

These two look similar, but behave very differently in photographic bathes. Sodium Sulfite is an essential ingredient in many photographic bathes, whereas Glauber's salt is almost irrelevant.

Not strictly true Sodium Sulphate is used in tropical developers to help reduce the emulsion swelling.

Sulfite and thiosulfite are both used to reduce chlorine levels. Sodium sulfite also used in wine-making, food preservation, etc. Food grade is good enough for most darkroom formulas. I would not hesitate to use it for a substitute HCA but in a color developer I would use photograde, source it from the same place you got your CD-1.

Never heard of Thiosulphite. I suspect you mean Metabisulphite or the less pure US version Bisulphite. JT Baker sell both - Bisulphite is usually around 95% Metabisulphite the rest Bisulphite although Kodak's could be a lower Metabisulphite content 90% springs to mind, it's largely differences in manufacture. Food grade is the same as Photographic grade in most cases/

Ian

 

[Bob Carnie]

Where in Canada would I be able to buy Food grade Sodium Sulfite?? any takers

 

[Patrick Robert James]

I get sodium sulfite at the pool supply- Leslie's. It says right on the package it is over 99% sodium sulfite with a trace amount of sodium sulfate. I suppose the trace amount would have little effect. I buy it there just for the convenience.

Some pool supply places have thiosulfate as well if you fancy mixing up your own fixer. As someone said above, they are both used to reduce chlorine, not that I am an expert on that. Just what it says on the bottle....

 

[Mr Bill]

It says right on the package it is over 99% sodium sulfite with a trace amount of sodium sulfate.

Yes, should be no problem. This is what happens when it is exposed to air, it oxidizes to sulfate; this is basically how it becomes "used up" when it is protecting the developing agent in a developer solution. So if there's any sulfate in it, this is really equivalent to just being slightly used.

The more pertinent thing is what other impurities may be in it, and whether these affect your usage. In a fixer or a bleach-fix for paper, most things are not a problem. But for sulfite used in a developer there could be issues. You sort of need to have an idea how sensitive things could be. If you don't have such knowledge, the safest thing is probably to buy official photo grade, OR by from an oufit that caters to photographers (THEY will have already made the judgment). Or, if you have more time than money, you might want to buy the cheapest and do your own testing.

Food grade is the same as Photographic grade in most cases/

Well, this may be true for practical purposes, but the formal standards are most definitely not the same. For example, food grade is pretty loose on iron content, whereas photo grade is not. (If they had a specific photographic FIXER grade, it would probably allow higher iron content.) I spent time as the QC manager at an outfit mixing or regenerating thousands of gallons of replenishers every day; we had copies of the ANSI photograde standards for dozens of chemicals, and we did analytical screening before "approving" any new supplier. I'm just saying that I have had some familiarity with photograde chemical standards.

 

[MattKing]

Where in Canada would I be able to buy Food grade Sodium Sulfite?? any takers

Does this alternative help? https://www.amazon.ca/EMS-21300-Sod...qid=1529802486&sr=1-1&keywords=sodium+sulfite

 

[darkroommike]

Not strictly true Sodium Sulphate is used in tropical developers to help reduce the emulsion swelling.



Never heard of Thiosulphite. I suspect you mean Metabisulphite or the less pure US version Bisulphite. JT Baker sell both - Bisulphite is usually around 95% Metabisulphite the rest Bisulphite although Kodak's could be a lower Metabisulphite content 90% springs to mind, it's largely differences in manufacture. Food grade is the same as Photographic grade in most cases/

Ian

My bad Ian, I, of course meant Sodium Thiosulfate (excuse the American spelling) used for all sorts of interesting things including de-chlorination.

 

[dpurdy]

RE pool supply Sodium Sulfite, I am on my second 50 pound bag from a local shop and if it isn't working right I can't tell. I mix paper developer and film developer with it.